从相机中选择照片扫描以及加载二维码扫描界面

1.xml中的写法：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/zxing"
        android:id="@+id/btn_1"/>
    <Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/tp"
    android:id="@+id/btn_2"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/dz"
        android:id="@+id/btn_3"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/cs"
        android:id="@+id/btn_4"/>
</LinearLayout>



2.mainactivity中的写法

package com.example.w.lianxi66;

import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.uuzuche.lib_zxing.activity.CaptureActivity;
import com.uuzuche.lib_zxing.activity.CodeUtils;
import com.uuzuche.lib_zxing.activity.ZXingLibrary;

import utils.CheckPermissionUtils;
import utils.ImageUtil;

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_IMAGE =2;
    private static final int REQUEST_CODE =1 ;
    private Button btn_1;
    private Button btn_2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ZXingLibrary.initDisplayOpinion(this);
        btn_1 = findViewById(R.id.btn_1);
        btn_2 = findViewById(R.id.btn_2);
        initPermission();
        btn_1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
                startActivityForResult(intent,REQUEST_CODE);
            }
        });

      btn_2.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
              intent.addCategory(Intent.CATEGORY_OPENABLE);
              intent.setType("image/*");
              startActivityForResult(intent,REQUEST_IMAGE);
          }
      });


    }

    private void initPermission() {
        String[] permissions = CheckPermissionUtils.checkPermission(this);
        if (permissions.length == 0) {
            //权限都申请了
            //是否登录
        } else {
            //申请权限
            ActivityCompat.requestPermissions(this, permissions, 100);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case REQUEST_CODE:
                if (requestCode==REQUEST_CODE) {
                    //处理扫面结果，在界面上显示
                    if (data!=null) {
                        Bundle bundle = data.getExtras();
                        if (bundle==null) {
                            return;
                        }
                        if (bundle.getInt(CodeUtils.RESULT_TYPE)==CodeUtils.RESULT_SUCCESS) {
                            String result = bundle.getString(CodeUtils.RESULT_STRING);
                            Toast.makeText(this, "解析结果:" + result, Toast.LENGTH_LONG).show();
                        } else if (bundle.getInt(CodeUtils.RESULT_TYPE) == CodeUtils.RESULT_FAILED) {
                            Toast.makeText(MainActivity.this,"解析二维码失败", Toast.LENGTH_LONG).show();
                        }

                    }
                }
                break;
                case REQUEST_IMAGE:
                    if (requestCode == REQUEST_IMAGE) {
                        if (data != null) {
                            Uri uri = data.getData();
                            try {
                                CodeUtils.analyzeBitmap(ImageUtil.getImageAbsolutePath(this, uri), new CodeUtils.AnalyzeCallback() {
                                    @Override
                                    public void onAnalyzeSuccess(Bitmap mBitmap, String result) {
                                        Toast.makeText(MainActivity.this, "解析结果:" + result, Toast.LENGTH_LONG).show();
                                        Log.i("ZxingActivity.this", "二维码图片识别==: " + result);
                                    }
                                    @Override
                                    public void onAnalyzeFailed() {
                                        Toast.makeText(MainActivity.this, "解析二维码失败", Toast.LENGTH_LONG).show();


                                    }
                                });
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }


                    }
                    break;
        }

    }


}



3.工具类1

package utils;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.support.v4.content.ContextCompat;

import java.util.ArrayList;
import java.util.List;

public class CheckPermissionUtils {
    private CheckPermissionUtils() {
    }

    //需要申请的权限
    private static String[] permissions = new String[]{
            Manifest.permission.WRITE_EXTERNAL_STORAGE,
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.CAMERA,
            Manifest.permission.SEND_SMS
    };

    //检测权限
    public static String[] checkPermission(Context context){
        List<String> data = new ArrayList<>();//存储未申请的权限
        for (String permission : permissions) {
            int checkSelfPermission = ContextCompat.checkSelfPermission(context, permission);
            if(checkSelfPermission == PackageManager.PERMISSION_DENIED){//未申请
                data.add(permission);
            }
        }
        return data.toArray(new String[data.size()]);
    }
}

4.工具类2

package utils;

import android.annotation.TargetApi;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;

public class ImageUtil {
    @TargetApi(19)
    public static String getImageAbsolutePath(Context context, Uri imageUri) {
        if (context == null || imageUri == null)
            return null;
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT && DocumentsContract.isDocumentUri(context, imageUri)) {
            if (isExternalStorageDocument(imageUri)) {
                String docId = DocumentsContract.getDocumentId(imageUri);
                String[] split = docId.split(":");
                String type = split[0];
                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
            } else if (isDownloadsDocument(imageUri)) {
                String id = DocumentsContract.getDocumentId(imageUri);
                Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
                return getDataColumn(context, contentUri, null, null);
            } else if (isMediaDocument(imageUri)) {
                String docId = DocumentsContract.getDocumentId(imageUri);
                String[] split = docId.split(":");
                String type = split[0];
                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                String selection = MediaStore.Images.Media._ID + "=?";
                String[] selectionArgs = new String[]{split[1]};
                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        } // MediaStore (and general)
        else if ("content".equalsIgnoreCase(imageUri.getScheme())) {
            // Return the remote address
            if (isGooglePhotosUri(imageUri))
                return imageUri.getLastPathSegment();
            return getDataColumn(context, imageUri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(imageUri.getScheme())) {
            return imageUri.getPath();
        }
        return null;
    }

    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is Google Photos.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }

    public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
        Cursor cursor = null;
        String column = MediaStore.Images.Media.DATA;
        String[] projection = {column};
        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }
}

5.所需的权限

<uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.FLASHLIGHT" />

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

    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET" />

6，build.gradle中的权限implementation 'cn.yipianfengye.android:zxing-library:2.2'