编写一个日志记载程序，可以记录身边的不良现象

创建一个Criminallntent应用，并且向Java包中编写以下类：

Crime:

package com.bignerdranch.android.criminalintent;

import java.util.Date;
import java.util.UUID;

public class Crime {

    private UUID mId;//UUID是Android框架里的java工具类，有了它方便产生唯一的ID值
    private String mTitle;
    private Date mDate;
    private boolean mSolved;
    private String mSuspect;

    public Crime() {
        this(UUID.randomUUID());//随机产生一个ID值
    }

    public Crime(UUID id) {
        mId = id;
        mDate = new Date();
    }
//自动生成的getter方法和setter方法
    public UUID getId() {
        return mId;
    }

    public String getTitle() {
        return mTitle;
    }

    public void setTitle(String title) {
        mTitle = title;
    }

    public Date getDate() {
        return mDate;
    }

    public void setDate(Date date) {
        mDate = date;
    }

    public boolean isSolved() {
        return mSolved;
    }

    public void setSolved(boolean solved) {
        mSolved = solved;
    }

    public String getSuspect() {
        return mSuspect;
    }

    public void setSuspect(String suspect) {
        mSuspect = suspect;
    }

    public String getPhotoFilename() {
        return "IMG_" + getId().toString() + ".jpg";
    }
}

CrimeFragment:
package com.bignerdranch.android.criminalintent;

import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.provider.MediaStore;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.content.FileProvider;
import android.text.Editable;
import android.text.TextWatcher;
import android.text.format.DateFormat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ImageView;

import java.io.File;
import java.util.Date;
import java.util.List;
import java.util.UUID;

import static android.widget.CompoundButton.*;
//让CrimeFragment继承Fragment类，这里继承的是Fragment(android.support.v4.app)是支持库版
public class CrimeFragment extends Fragment {

    private static final String ARG_CRIME_ID = "crime_id";
    private static final String DIALOG_DATE = "DialogDate";
//设置目标fragment
    private static final int REQUEST_DATE = 0;
    private static final int REQUEST_CONTACT = 1;
    private static final int REQUEST_PHOTO = 2;

    private Crime mCrime;
    private File mPhotoFile;
    private EditText mTitleField;
    private Button mDateButton;
    private CheckBox mSolvedCheckbox;
    private Button mReportButton;
    private Button mSuspectButton;
    private ImageButton mPhotoButton;
    private ImageView mPhotoView;

//编写newInstance（UUID）方法
    public static CrimeFragment newInstance(UUID crimeId) {
        Bundle args = new Bundle();
        args.putSerializable(ARG_CRIME_ID, crimeId);

        CrimeFragment fragment = new CrimeFragment();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {//这是公用方法，托管fragment的activity要调用它们
        super.onCreate(savedInstanceState);
        //获取rxtra数据并取得Crime对象
        UUID crimeId = (UUID) getArguments().getSerializable(ARG_CRIME_ID);
        mCrime = CrimeLab.get(getActivity()).getCrime(crimeId);
        mPhotoFile = CrimeLab.get(getActivity()).getPhotoFile(mCrime);
    }

    @Override//配置视图和fragment的关联
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        //这里有三个参数，第一个是fragment的视图直接调用LayoutInflater inflater生成的
        //第二个参数是视图的父视图，通常需要父视图来正确配置组件
        //第三个参数告诉布局生成器是否将生成的视图添加给父视图
        View v = inflater.inflate(R.layout.fragment_crime, container, false);

        mTitleField = (EditText) v.findViewById(R.id.crime_title);
        mTitleField.setText(mCrime.getTitle());//更新视图对象
        mTitleField.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                mCrime.setTitle(s.toString());
            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });
//禁用Button按钮，确保它不会影响用户的点击，长期处于灰色的状态，用户一看就知道是不可以按的。
        mDateButton = (Button) v.findViewById(R.id.crime_date);
        updateDate();
        mDateButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                FragmentManager manager = getFragmentManager();
                DatePickerFragment dialog = DatePickerFragment
                        .newInstance(mCrime.getDate());
                dialog.setTargetFragment(CrimeFragment.this, REQUEST_DATE);
                dialog.show(manager, DIALOG_DATE);
            }
        });

        mSolvedCheckbox = (CheckBox) v.findViewById(R.id.crime_solved);
        mSolvedCheckbox.setChecked(mCrime.isSolved());
        mSolvedCheckbox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, 
                    boolean isChecked) {
                mCrime.setSolved(isChecked);
            }
        });

        mReportButton = (Button) v.findViewById(R.id.crime_report);
        mReportButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent i = new Intent(Intent.ACTION_SEND);
                i.setType("text/plain");
                i.putExtra(Intent.EXTRA_TEXT, getCrimeReport());
                i.putExtra(Intent.EXTRA_SUBJECT,
                        getString(R.string.crime_report_subject));
                i = Intent.createChooser(i, getString(R.string.send_report));
                startActivity(i);
            }
        });

        final Intent pickContact = new Intent(Intent.ACTION_PICK,
                ContactsContract.Contacts.CONTENT_URI);
        mSuspectButton = (Button) v.findViewById(R.id.crime_suspect);
        mSuspectButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                startActivityForResult(pickContact, REQUEST_CONTACT);
            }
        });
        if (mCrime.getSuspect() != null) {
            mSuspectButton.setText(mCrime.getSuspect());
        }

        PackageManager packageManager = getActivity().getPackageManager();
        if (packageManager.resolveActivity(pickContact,
                PackageManager.MATCH_DEFAULT_ONLY) == null) {
            mSuspectButton.setEnabled(false);
        }

        mPhotoButton = (ImageButton) v.findViewById(R.id.crime_camera);
        final Intent captureImage = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        boolean canTakePhoto = mPhotoFile != null &&
                captureImage.resolveActivity(packageManager) != null;
        mPhotoButton.setEnabled(canTakePhoto);
//按钮的监听器
        mPhotoButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Uri uri = FileProvider.getUriForFile(getActivity(),
                        "com.bignerdranch.android.criminalintent.fileprovider",
                        mPhotoFile);
                captureImage.putExtra(MediaStore.EXTRA_OUTPUT, uri);

                List<ResolveInfo> cameraActivities = getActivity()
                        .getPackageManager().queryIntentActivities(captureImage,
                                PackageManager.MATCH_DEFAULT_ONLY);

                for (ResolveInfo activity : cameraActivities) {
                    getActivity().grantUriPermission(activity.activityInfo.packageName,
                            uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
                }

                startActivityForResult(captureImage, REQUEST_PHOTO);
            }
        });

        mPhotoView = (ImageView) v.findViewById(R.id.crime_photo);
        updatePhotoView();

        return v;
    }

    @Override
    public void onPause() {
        super.onPause();

        CrimeLab.get(getActivity())
                .updateCrime(mCrime);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode != Activity.RESULT_OK) {
            return;
        }

        if (requestCode == REQUEST_DATE) {
            Date date = (Date) data
                    .getSerializableExtra(DatePickerFragment.EXTRA_DATE);
            mCrime.setDate(date);
            updateDate();
        } else if (requestCode == REQUEST_CONTACT && data != null) {
            Uri contactUri = data.getData();
            // 指明你希望返回的区域
            // values for.
            String[] queryFields = new String[]{
                    ContactsContract.Contacts.DISPLAY_NAME
            };
            // Perform your query - the contactUri is like a "where"
            // clause here
            Cursor c = getActivity().getContentResolver()
                    .query(contactUri, queryFields, null, null, null);
            try {
                // Double-check that you actually got results
                if (c.getCount() == 0) {
                    return;
                }
                // 清空第一列第一行的数据
                // 嫌疑人的姓名
                c.moveToFirst();
                String suspect = c.getString(0);
                mCrime.setSuspect(suspect);
                mSuspectButton.setText(suspect);
            } finally {
                c.close();
            }
        } else if (requestCode == REQUEST_PHOTO) {
            Uri uri = FileProvider.getUriForFile(getActivity(),
                    "com.bignerdranch.android.criminalintent.fileprovider",
                    mPhotoFile);

            getActivity().revokeUriPermission(uri,
                    Intent.FLAG_GRANT_WRITE_URI_PERMISSION);

            updatePhotoView();
        }
    }

    private void updateDate() {
        mDateButton.setText(mCrime.getDate().toString());
    }
//反馈案件信息
    private String getCrimeReport() {
        String solvedString = null;
        if (mCrime.isSolved()) {
            solvedString = getString(R.string.crime_report_solved);
        } else {
            solvedString = getString(R.string.crime_report_unsolved);
        }
        String dateFormat = "EEE, MMM dd";
        String dateString = DateFormat.format(dateFormat, mCrime.getDate()).toString();
        String suspect = mCrime.getSuspect();
        if (suspect == null) {
            suspect = getString(R.string.crime_report_no_suspect);
        } else {
            suspect = getString(R.string.crime_report_suspect, suspect);
        }
        String report = getString(R.string.crime_report,
                mCrime.getTitle(), dateString, solvedString, suspect);
        return report;
    }
//更新照片视图
    private void updatePhotoView() {
        if (mPhotoFile == null || !mPhotoFile.exists()) {
            mPhotoView.setImageDrawable(null);
        } else {
            Bitmap bitmap = PictureUtils.getScaledBitmap(
                    mPhotoFile.getPath(), getActivity());
            mPhotoView.setImageBitmap(bitmap);
        }
    }
}

CrimeLab:
package com.bignerdranch.android.criminalintent;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import com.bignerdranch.android.criminalintent.database.CrimeBaseHelper;
import com.bignerdranch.android.criminalintent.database.CrimeCursorWrapper;
import com.bignerdranch.android.criminalintent.database.CrimeDbSchema;
import com.bignerdranch.android.criminalintent.database.CrimeDbSchema.CrimeTable;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

import static com.bignerdranch.android.criminalintent.database.CrimeDbSchema.CrimeTable.*;
import static com.bignerdranch.android.criminalintent.database.CrimeDbSchema.CrimeTable.Cols.*;

public class CrimeLab {
    private static CrimeLab sCrimeLab;
    //注意sCrimeLab变量的s前缀，表示static，看到此前缀就大致猜出它是一个静态变量
    private Context mContext;
    private SQLiteDatabase mDatabase;
//其他类创建CrimeLab对象的唯一方法是使用下面这个get（）方法
    public static CrimeLab get(Context context) {
        if (sCrimeLab == null) {
            sCrimeLab = new CrimeLab(context);//传入context对象
        }

        return sCrimeLab;
    }

    private CrimeLab(Context context) {
        mContext = context.getApplicationContext();
        mDatabase = new CrimeBaseHelper(mContext)
                .getWritableDatabase();

    }

    public void addCrime(Crime c) {
        ContentValues values = getContentValues(c);
        mDatabase.insert(CrimeTable.NAME, null, values);
    }

    public List<Crime> getCrimes() {
        List<Crime> crimes = new ArrayList<>();
        CrimeCursorWrapper cursor = queryCrimes(null, null);
        try {
            cursor.moveToFirst();
            while (!cursor.isAfterLast()) {
                crimes.add(cursor.getCrime());
                cursor.moveToNext();
            }
        } finally {
            cursor.close();
        }
        return crimes;
    }

    public Crime getCrime(UUID id) {
        CrimeCursorWrapper cursor = queryCrimes(
                CrimeTable.Cols.UUID + " = ?",
                new String[]{id.toString()}
        );
        try {
            if (cursor.getCount() == 0) {
                return null;
            }
            cursor.moveToFirst();
            return cursor.getCrime();
        } finally {
            cursor.close();
        }
    }

    public File getPhotoFile(Crime crime) {
        File filesDir = mContext.getFilesDir();
        return new File(filesDir, crime.getPhotoFilename());
    }

    public void updateCrime(Crime crime) {
        String uuidString = crime.getId().toString();
        ContentValues values = getContentValues(crime);
        mDatabase.update(CrimeTable.NAME, values,
                CrimeTable.Cols.UUID + " = ?",
                new String[]{uuidString});
    }

    private CrimeCursorWrapper queryCrimes(String whereClause, String[] whereArgs) {
        Cursor cursor = mDatabase.query(
                CrimeTable.NAME,
                null, // Columns - null selects all columns
                whereClause,
                whereArgs,
                null, // groupBy
                null, // having
                null  // orderBy
        );
        return new CrimeCursorWrapper(cursor);
    }

    private static ContentValues getContentValues(Crime crime) {
        ContentValues values = new ContentValues();
        values.put(UUID, crime.getId().toString());
        values.put(TITLE, crime.getTitle());
        values.put(DATE, crime.getDate().getTime());
        values.put(SOLVED, crime.isSolved() ? 1 : 0);
        values.put(CrimeTable.Cols.SUSPECT, crime.getSuspect());

        return values;
    }
}

CrimeListActivity:
package com.bignerdranch.android.criminalintent;

import android.support.v4.app.Fragment;
//表单动作类
public class CrimeListActivity extends SingleFragmentActivity {

    @Override
    protected Fragment createFragment() {
        return new CrimeListFragment();
    }
}

CrimeListFragment:
package com.bignerdranch.android.criminalintent;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

public class CrimeListFragment extends Fragment {

    private static final String SAVED_SUBTITLE_VISIBLE = "subtitle";

    private RecyclerView mCrimeRecyclerView;
    private CrimeAdapter mAdapter;
    private boolean mSubtitleVisible;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_crime_list, container, false);

        mCrimeRecyclerView = (RecyclerView) view
                .findViewById(R.id.crime_recycler_view);
        mCrimeRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

        if (savedInstanceState != null) {
            mSubtitleVisible = savedInstanceState.getBoolean(SAVED_SUBTITLE_VISIBLE);
        }

        updateUI();

        return view;
    }

    @Override
    public void onResume() {
        super.onResume();
        updateUI();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putBoolean(SAVED_SUBTITLE_VISIBLE, mSubtitleVisible);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
        inflater.inflate(R.menu.fragment_crime_list, menu);

        MenuItem subtitleItem = menu.findItem(R.id.show_subtitle);
        if (mSubtitleVisible) {
            subtitleItem.setTitle(R.string.hide_subtitle);
        } else {
            subtitleItem.setTitle(R.string.show_subtitle);
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.new_crime:
                Crime crime = new Crime();
                CrimeLab.get(getActivity()).addCrime(crime);
                Intent intent = CrimePagerActivity
                        .newIntent(getActivity(), crime.getId());
                startActivity(intent);
                return true;
            case R.id.show_subtitle:
                mSubtitleVisible = !mSubtitleVisible;
                getActivity().invalidateOptionsMenu();
                updateSubtitle();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    private void updateSubtitle() {
        CrimeLab crimeLab = CrimeLab.get(getActivity());
        int crimeCount = crimeLab.getCrimes().size();
        String subtitle = getString(R.string.subtitle_format, crimeCount);

        if (!mSubtitleVisible) {
            subtitle = null;
        }

        AppCompatActivity activity = (AppCompatActivity) getActivity();
        activity.getSupportActionBar().setSubtitle(subtitle);
    }

    private void updateUI() {
        CrimeLab crimeLab = CrimeLab.get(getActivity());
        List<Crime> crimes = crimeLab.getCrimes();

        if (mAdapter == null) {
            mAdapter = new CrimeAdapter(crimes);
            mCrimeRecyclerView.setAdapter(mAdapter);
        } else {
            mAdapter.setCrimes(crimes);
            mAdapter.notifyDataSetChanged();
        }

        updateSubtitle();
    }

    private class CrimeHolder extends RecyclerView.ViewHolder
            implements View.OnClickListener {

        private Crime mCrime;

        private TextView mTitleTextView;
        private TextView mDateTextView;
        private ImageView mSolvedImageView;//初始化图片信息
//定义CrimeHolder内部类，它会实例化并使用list_item_crime布局
        public CrimeHolder(LayoutInflater inflater, ViewGroup parent) {
            //实例化list_item_crime布局并传给super（）方法，即ViewHolder的构造方法
            super(inflater.inflate(R.layout.list_item_crime, parent, false));
            itemView.setOnClickListener(this);

            mTitleTextView = (TextView) itemView.findViewById(R.id.crime_title);
            mDateTextView = (TextView) itemView.findViewById(R.id.crime_date);
            mSolvedImageView = (ImageView) itemView.findViewById(R.id.crime_solved);
            //控制图片显示
        }

        public void bind(Crime crime) {
            mCrime = crime;
            mTitleTextView.setText(mCrime.getTitle());
            mDateTextView.setText(mCrime.getDate().toString());
            mSolvedImageView.setVisibility(crime.isSolved() ? View.VISIBLE : View.GONE);
        }

        @Override
        public void onClick(View view) {
            Intent intent = CrimePagerActivity.newIntent(getActivity(), mCrime.getId());
            //传递Crime实例
            startActivity(intent);
        }
    }

    private class CrimeAdapter extends RecyclerView.Adapter<CrimeHolder> {

        private List<Crime> mCrimes;

        public CrimeAdapter(List<Crime> crimes) {
            mCrimes = crimes;
        }

        @Override
        public CrimeHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
            return new CrimeHolder(layoutInflater, parent);
        }

        @Override
        public void onBindViewHolder(CrimeHolder holder, int position) {
            Crime crime = mCrimes.get(position);
            holder.bind(crime);
        }

        @Override
        public int getItemCount() {
            return mCrimes.size();
        }

        public void setCrimes(List<Crime> crimes) {
            mCrimes = crimes;
        }
    }
}

CrimePagerActivity:
package com.bignerdranch.android.criminalintent;

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;

import java.util.List;
import java.util.UUID;

public class CrimePagerActivity extends AppCompatActivity {

    private static final String EXTRA_CRIME_ID =
            "com.bignerdranch.android.criminalintent.crime_id";

    private ViewPager mViewPager;
    private List<Crime> mCrimes;

    public static Intent newIntent(Context packageContext, UUID crimeId) {
        Intent intent = new Intent(packageContext, CrimePagerActivity.class);
        intent.putExtra(EXTRA_CRIME_ID, crimeId);
        return intent;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_crime_pager);

        UUID crimeId = (UUID) getIntent()
                .getSerializableExtra(EXTRA_CRIME_ID);

        mViewPager = (ViewPager) findViewById(R.id.crime_view_pager);

        mCrimes = CrimeLab.get(this).getCrimes();
        FragmentManager fragmentManager = getSupportFragmentManager();
        //设置adapter为FragmentStatePagerAdapter的一个匿名实例
        mViewPager.setAdapter(new FragmentStatePagerAdapter(fragmentManager) {

            @Override
            public Fragment getItem(int position) {
                Crime crime = mCrimes.get(position);
                return CrimeFragment.newInstance(crime.getId());
            }

            @Override
            public int getCount() {
                return mCrimes.size();
            }
        });

        for (int i = 0; i < mCrimes.size(); i++) {
            if (mCrimes.get(i).getId().equals(crimeId)) {
                mViewPager.setCurrentItem(i);
                break;
            }
        }
    }
}

DatePickerFragment:
package com.bignerdranch.android.criminalintent;

import android.app.Activity;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.DatePicker;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class DatePickerFragment extends DialogFragment {

    public static final String EXTRA_DATE =
            "com.bignerdranch.android.criminalintent.date";

    private static final String ARG_DATE = "date";

    private DatePicker mDatePicker;
//传递数据给DatePickerFragment
    public static DatePickerFragment newInstance(Date date) {
        Bundle args = new Bundle();
        args.putSerializable(ARG_DATE, date);
//获取 Date对象并初始化DatePicker
        DatePickerFragment fragment = new DatePickerFragment();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Date date = (Date) getArguments().getSerializable(ARG_DATE);

        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DAY_OF_MONTH);

        View v = LayoutInflater.from(getActivity())
                .inflate(R.layout.dialog_date, null);

        mDatePicker = (DatePicker) v.findViewById(R.id.dialog_date_picker);
        mDatePicker.init(year, month, day, null);

        return new AlertDialog.Builder(getActivity())
                .setView(v)
                .setTitle(R.string.date_picker_title)
                .setPositiveButton(android.R.string.ok,
                        new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                int year = mDatePicker.getYear();
                                int month = mDatePicker.getMonth();
                                int day = mDatePicker.getDayOfMonth();
                                Date date = new GregorianCalendar(year, month, day).getTime();
                                sendResult(Activity.RESULT_OK, date);
                            }
                        })
                .create();
    }

    private void sendResult(int resultCode, Date date) {
        if (getTargetFragment() == null) {
            return;
        }

        Intent intent = new Intent();
        intent.putExtra(EXTRA_DATE, date);

        getTargetFragment()
                .onActivityResult(getTargetRequestCode(), resultCode, intent);
    }
}

PictureUtils:
package com.bignerdranch.android.criminalintent;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Point;

public class PictureUtils {
    public static Bitmap getScaledBitmap(String path, Activity activity) {
        Point size = new Point();
        activity.getWindowManager().getDefaultDisplay()
                .getSize(size);
        return getScaledBitmap(path, size.x, size.y);
    }

    public static Bitmap getScaledBitmap(String path, int destWidth, int destHeight) {
        // Read in the dimensions of the image on disk
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        float srcWidth = options.outWidth;
        float srcHeight = options.outHeight;

        // Figure out how much to scale down by
        int inSampleSize = 1;
        if (srcHeight > destHeight || srcWidth > destWidth) {
            float heightScale = srcHeight / destHeight;
            float widthScale = srcWidth / destWidth;

            inSampleSize = Math.round(heightScale > widthScale ? heightScale :
                    widthScale);
        }

        options = new BitmapFactory.Options();
        options.inSampleSize = inSampleSize;

        // Read in and create final bitmap
        return BitmapFactory.decodeFile(path, options);
    }
}

SingleFragmentActivity:
package com.bignerdranch.android.criminalintent;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.AppCompatActivity;
//几乎每次新建activity都要使用这样的代码，为了避免重复，我们将这段代码直接封装在抽象类里面
public abstract class SingleFragmentActivity extends AppCompatActivity {
//添加一个通用的超类
    protected abstract Fragment createFragment();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment);

        FragmentManager fm = getSupportFragmentManager();
        Fragment fragment = fm.findFragmentById(R.id.fragment_container);

        if (fragment == null) {
            fragment = createFragment();
            fm.beginTransaction()
                    .add(R.id.fragment_container, fragment)
                    .commit();
        }
    }
}

以上只是Java类的代码部分，还需要编写xml部件代码才能正常运行

下面是xml：

在src包中添加如下组件代码（后缀均为.xml）：

AndroidManifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.bignerdranch.android.criminalintent">

    <uses-feature
        android:name="android.hardware.camera"
        android:required="false" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <!--配置主界面的crime列表，配置crimelistativity为launcher activity-->
        <activity android:name=".CrimeListActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <!--嫌疑人姓名信息-->
        <activity
            android:name=".CrimePagerActivity"
            android:parentActivityName=".CrimeListActivity">
        </activity>
        <!--提供商信息-->
        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.bignerdranch.android.criminalintent.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/files" />
        </provider>
    </application>

</manifest>

activity_crime_pager:
<!--动态嫌疑人页面的组件-->
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
                                   android:id="@+id/crime_view_pager"
                                   android:layout_width="match_parent"
                                   android:layout_height="match_parent" />

activity_fragment:
<!--动态片段组件-->
<FrameLayout android:id="@+id/fragment_container"
             xmlns:android="http://schemas.android.com/apk/res/android"
             android:layout_width="match_parent"
             android:layout_height="match_parent" />

dialog_date:
<!--日志数据组件-->
<?xml version="1.0" encoding="utf-8"?>
<DatePicker xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/dialog_date_picker"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:calendarViewShown="false"/>

fragment_crime:
<!--日志数据组件-->
<?xml version="1.0" encoding="utf-8"?>
<DatePicker xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/dialog_date_picker"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:calendarViewShown="false"/>

fragment_crime_list:
<?xml version="1.0" encoding="utf-8"?>
<!--使用utf-8可以适应中文输入-->
<!--配置CrimeListFragment的视图，使其和父视图-->
<android.support.v7.widget.RecyclerView android:id="@+id/crime_recycler_view"
                                        xmlns:android="http://schemas.android.com/apk/res/android"
                                        android:layout_width="match_parent"
                                        android:layout_height="match_parent"/>

list_item_crime:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
                                             xmlns:app="http://schemas.android.com/apk/res-auto"
                                             xmlns:tools="http://schemas.android.com/tools"
                                             android:layout_width="match_parent"
                                             android:layout_height="wrap_content"
                                             android:orientation="vertical"
    >

    <TextView
        android:id="@+id/crime_title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="Crime Title"
        android:textColor="@android:color/black"
        android:textSize="18sp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@+id/crime_solved"
        app:layout_constraintTop_toTopOf="parent"/>
<!--以layout开头的属性都属于局部参数，用来向父组件做指示，告诉父布局如何安排自己-->
    <TextView
        android:id="@+id/crime_date"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Crime Date"
        android:layout_marginStart="16dp"
        app:layout_constraintLeft_toLeftOf="parent"
        android:layout_marginTop="8dp"
        app:layout_constraintTop_toBottomOf="@+id/crime_title"
        app:layout_constraintRight_toLeftOf="@+id/crime_solved"
        android:layout_marginEnd="8dp"/>

    <ImageView
        android:id="@+id/crime_solved"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:srcCompat="@drawable/ic_solved"
        android:layout_marginTop="16dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="16dp"
        android:layout_marginEnd="16dp"
        app:layout_constraintRight_toRightOf="parent"/>
</android.support.constraint.ConstraintLayout>

values:
colors:
<!--色彩控制组件-->
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <!--浅蓝-->
    <color name="colorPrimaryDark">#303F9F</color>
    <!--深蓝-->
    <color name="colorAccent">#FF4081</color>
    <!--粉色-->
</resources>

strings:
<!--包含Crime类实例中的信息-->
<resources>
    <string name="app_name">CriminalIntent</string>
    <string name="crime_title_hint">Enter a title for the crime.</string>
    <string name="crime_title_label">Title</string>
    <string name="crime_details_label">Details</string>
    <string name="crime_solved_label">Solved</string>
    <string name="date_picker_title">Date of crime:</string>
    <!--为对话框添加字符串资源-->
    <string name="new_crime">New Crime</string>
    <string name="show_subtitle">Show Subtitle</string>
    <string name="hide_subtitle">Hide Subtitle</string>
    <string name="subtitle_format">%1$d crimes</string>
    <string name="crime_suspect_text">Choose Suspect</string>
    <string name="crime_report_text">Send Crime Report</string>
    <string name="crime_report">%1$s!
    The crime was discovered on %2$s. %3$s, and %4$s
        <!--字符串在屏幕上都能显示-->
  </string>
    <string name="crime_report_solved">The case is solved</string>
    <string name="crime_report_unsolved">The case is not solved</string>
    <string name="crime_report_no_suspect">there is no suspect.</string>
    <string name="crime_report_suspect">the suspect is %s.</string>
    <string name="crime_report_subject">CriminalIntent Crime Report</string>
    <string name="send_report">Send crime report via</string>
</resources>

styles:
<resources>

    <!-- 应用主题组件-->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- 设置应用颜色风格-->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

</resources>

 

运行结果：

完成了记录主题时间、拍照、发送给联系人的功能，还可以设定问题是否被解决的一个勾选框。