Calendar slide

/////////////////////////////////////// Code

package com.example.administrator.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class MainActivity extends AppCompatActivity {
    private Date date1;
    private Date date2;
    /**
     * 左面点击
     */
    TextView mIvLeftClick;

    /**
     * 右面点击
     */
    TextView mIvRightClick;
    /**
     * 年月
     */
    TextView tvYearMonthSet;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvYearMonthSet = findViewById(R.id.tv_year_month_set);
        mIvLeftClick = findViewById(R.id.iv_left_click);
        mIvRightClick = findViewById(R.id.iv_right_click);
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM");
        try {
            date1 = dateFormat.parse("2012-01");//最小时间(日历起始时间)
            date2 = dateFormat.parse("2012-10");//最大时间
        } catch (ParseException e) {
            e.printStackTrace();
        }
        //时间左面点击
        mIvLeftClick.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    ComitTimeDown(date1);
                } catch (ParseException e) {
                    e.printStackTrace();
                }
                if (tvYearMonthSet.getText().toString().equals("2012-01")) {
                    mIvLeftClick.setVisibility(View.GONE);
                }
            }
        });
        //时间右面点击
        mIvRightClick.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                {the try 
                    ComitTimeUp (DATE2); 
                } the catch (a ParseException E) { 
                    e.printStackTrace (); 
                } 
                IF (.. tvYearMonthSet.getText () toString () the equals ( "2012-10")) { 
                    mIvRightClick.setVisibility (View.GONE ); 
                } 
            } 
        }); 
    } 

    Private String ComitTimeDown (a Date date1) {throws a ParseException 
        the SimpleDateFormat new new DF = the SimpleDateFormat ( "the MM-YYYY"); 
        a Date DATE = df.parse (tvYearMonthSet.getText () toString ());. 
        / / 1 start time end time is less than 2 the same start time and end time is greater than the start time end time 3 
        if (date.getTime () <date1.getTime ( )) {
            //结束时间小于开始时间
            mIvLeftClick.setVisibility(View.GONE);
            mIvRightClick.setVisibility(View.VISIBLE);
            return null;
        } else if (date.getTime() == date1.getTime()) {
            //开始时间与结束时间相同
            mIvLeftClick.setVisibility(View.GONE);
            mIvRightClick.setVisibility(View.VISIBLE);
            return null;
        } else if (date.getTime() > date1.getTime()) {
            mIvLeftClick.setVisibility(View.VISIBLE);
            mIvRightClick.setVisibility(View.VISIBLE);
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            calendar.add(Calendar.MONTH, -1);
            tvYearMonthSet.setText (df.format (calendar.getTime ())); 
        } 
        return null; 
    } 

    Private String ComitTimeUp (a Date DATE2) {throws a ParseException 
        the SimpleDateFormat new new DF = the SimpleDateFormat ( "the MM-YYYY"); 
        a Date DATE = df.parse (tvYearMonthSet.getText () toString ().); 
        // start time is less than the end time. 1 2 start time and end time is larger than the same time as the start time of the end 3 
        IF (date.getTime ()> date2.getTime ()) { 
            // start time end time is less than 
            mIvRightClick.setVisibility (View.GONE); 
            mIvLeftClick.setVisibility (View.VISIBLE); 
            return null; 
        } the else IF (date.getTime () == date2.getTime ()) { 
            // start time and end same time
            mIvRightClick.setVisibility(View.GONE);
            mIvLeftClick.setVisibility(View.VISIBLE);
            return null;
        } else if (date.getTime() < date2.getTime()) {
            mIvRightClick.setVisibility(View.VISIBLE);
            mIvLeftClick.setVisibility(View.VISIBLE);
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(date);
            calendar.add(Calendar.MONTH, +1);
            tvYearMonthSet.setText(df.format(calendar.getTime()));
        }
        return null;
    }

}
//////////////////////////////////////样式

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="64dp"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:orientation="horizontal"
        android:paddingBottom="8dp"
        android:paddingTop="8dp">

        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_gravity="center_vertical"
            android:layout_weight="1">

            <TextView
                android:id="@+id/iv_left_click"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_gravity="center_vertical"
                android:text="左" />
        </LinearLayout>

        <TextView
            android:id="@+id/tv_year_month_set"
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_weight="2"
            android:text="2012-09"
            android:gravity="center" />

        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="48dp"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:gravity="end">

            <TextView
                android:id="@+id/iv_right_click"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_gravity="center_vertical"
                android:text="右" />
        </LinearLayout>
    </LinearLayout>

</LinearLayout>