一个简单的自定义Android日历

自定义的一个Android日历

1.先上图片

2.思路：

     布局是使用了两个Button，中间的一个TextView，最下方一个RecycelrVeiw。这不用多讲。最主要的还是如何获得日期并正确显示。

2.1如何获得日期

     通过Calendar类可以获得日期。

2.2如何显示

     首先获得当月1号是星期几，比如说2018/6/1是星期五，那么就应该让它显示在星期五上。对于之前的五月后几天，可以通过Calendar的add方法获得

3.布局代码

activity_main.xml:

<com.calendardemo.cjl.calendardemo.utils.calendarView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <Button
            android:layout_width="80dp"
            android:layout_height="50dp"
            android:layout_alignParentLeft="true"
            android:onClick="lastMonth"
            android:text="上一月"/>
        <TextView
            android:id="@+id/calendar_month_head"
            android:layout_width="80dp"
            android:layout_height="50dp"
            android:gravity="center"
            android:textSize="20dp"
            android:layout_centerInParent="true" />
        <Button
            android:layout_width="80dp"
            android:layout_height="50dp"
            android:layout_alignParentRight="true"
            android:onClick="nextMonth"
            android:text="下一月"/>
    </RelativeLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp" 
            android:layout_weight="1"
            android:textColor="#000000"
            android:text="日"/>
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="一"/>
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="二"/>
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="三"/>
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="四"/>
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="五"/>
        <TextView
            android:gravity="center"
            android:layout_width="0dp"
            android:layout_height="50dp"
            android:layout_weight="1"
            android:text="六"/>
        
    </LinearLayout>
    <android.support.v7.widget.RecyclerView
        android:id="@+id/calendar_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </android.support.v7.widget.RecyclerView>
</com.calendardemo.cjl.calendardemo.utils.calendarView>

4.recyclerview的item布局代码

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center"
    >
    <TextView
        android:id="@+id/recycler_view_item_tv"
        android:layout_width="35dp"
        android:layout_height="35dp"
        android:layout_marginLeft="15dp"
        android:gravity="center"
        android:text="25"
        android:textSize="20dp"/>

</LinearLayout>

6.MainAcivity：

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "cjl";
    private RecyclerView recyclerView;
    private Calendar calendar = Calendar.getInstance();
    private TextView textView;
    private List<DateUtils> dates = new ArrayList<>();
    private RecyclerViewAdapter adapter;
    private ChangerDateOfAdapter changerDateOfAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.calendar_month_head);
        recyclerView = (RecyclerView) findViewById(R.id.calendar_recycler_view);
        //更新数据
        refreshCaledar();

        int year = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH) + 1;
        textView.setText(String.valueOf(year) + "/" + String.valueOf(month));

        GridLayoutManager manager = new GridLayoutManager(getApplicationContext(), 7);
        adapter = new RecyclerViewAdapter(dates,this);
        recyclerView.setLayoutManager(manager);
        recyclerView.setAdapter(adapter);

    }
    public void setChangerDatrOfAdapter(ChangerDateOfAdapter changerDatrOfAdapter){
        this.changerDateOfAdapter=changerDatrOfAdapter;
    }

    /**
     * 上一个月
     */
    public void lastMonth(View v) {
        calendar.add(Calendar.MONTH, -1);
        int years = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH) + 1;
        textView.setText(String.valueOf(years) + "/" + String.valueOf(month));
        refreshCaledar();
        adapter.notifyDataSetChanged();
        changerDateOfAdapter.changerMonth(-1);
    }

    /**
     * 下一月
     */
    public void nextMonth(View v) {
        calendar.add(Calendar.MONTH, +1);
        int years = calendar.get(Calendar.YEAR);
        int month = calendar.get(Calendar.MONTH) + 1;
        textView.setText(String.valueOf(years) + "/" + String.valueOf(month));
        refreshCaledar();
        adapter.notifyDataSetChanged();
        changerDateOfAdapter.changerMonth(1);
    }

    // TODO: 2018/6/20 刷新控件
    private void refreshCaledar() {
        //清除list数据
        if (dates != null) {
            dates.clear();
        }
        //将原有的calendar复制
        Calendar calendars = (Calendar) calendar.clone();
        //将日改为1号，以用来确定1号为星期几
        calendars.set(Calendar.DAY_OF_MONTH, 1);
        //获得1号的星期
        int weekday = calendars.get(Calendar.DAY_OF_WEEK) - 1;
       //偏移calendas
        calendars.add(Calendar.DAY_OF_MONTH, -weekday);
        int maxNumber = 6 * 7;
        while (dates.size() < maxNumber) {
            int yaer = calendars.get(Calendar.YEAR);
            int month=calendars.get(Calendar.MONTH);
            int day=calendars.get(Calendar.DAY_OF_MONTH);
            DateUtils utils=new DateUtils();
            utils.setYear(yaer);
            utils.setMonth(month);
            utils.setDay(day);
            dates.add(utils);
            calendars.add(Calendar.DAY_OF_MONTH, 1);
        }
    }

}

7.recyclerview的Adapter代码

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder>
        implements ChangerDateOfAdapter {
    private static final String TAG = "cjl";
    private List<DateUtils> dateList;
    private Calendar calendar;
    private int nowYear;
    private int nowMonth;
    private int nowDay;
    private MainActivity mContext;
    private Calendar calendars;

    static class MyViewHolder extends RecyclerView.ViewHolder {
        TextView textView;

        public MyViewHolder(View itemView) {
            super(itemView);
            textView = (TextView) itemView.findViewById(R.id.recycler_view_item_tv);
        }
    }

    public RecyclerViewAdapter(List<DateUtils> dateList, MainActivity context) {
        this.dateList = dateList;
        this.mContext=context;
        calendar = Calendar.getInstance();
        calendars = (Calendar) calendar.clone();
        mContext.setChangerDatrOfAdapter(this);

    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_item, parent,
                false);
        MyViewHolder myViewHolder = new MyViewHolder(view);

        return myViewHolder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        DateUtils dateUtils = dateList.get(position);
        int year = dateUtils.getYear();
        int month = dateUtils.getMonth();
        int day = dateUtils.getDay();

        nowYear = calendar.get(Calendar.YEAR);
        nowMonth = calendar.get(Calendar.MONTH);
        nowDay = calendar.get(Calendar.DAY_OF_MONTH);

        int months=calendars.get(Calendar.MONTH);

        if (year == nowYear && month == nowMonth && day == nowDay) {
            holder.textView.setTextColor(Color.parseColor("#FF00FF"));
        }
        if (month != months) {
            holder.textView.setTextColor(Color.parseColor("#D1CB07"));
            Log.i(TAG, "yanse: ");
        }
        holder.textView.setText(String.valueOf(day));
    }

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

    @Override
    public void changerMonth(int i) {
        calendars.add(Calendar.MONTH,i);
    }
}