习题4 3-6

package com.example.ex3_6;

import android.app.DatePickerDialog;
import android.app.ProgressDialog;
import android.app.TimePickerDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;
import android.view.View.OnClickListener;

public class MainActivity extends AppCompatActivity {
    Button btn1,btn2,btn3;
    TextView txt;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn1=findViewById(R.id.button1);
        btn2=findViewById(R.id.button2);
        btn3=findViewById(R.id.button3);
        txt=findViewById(R.id.text);
        btn1.setOnClickListener(new mClick());
        btn2.setOnClickListener(new mClick());
        btn3.setOnClickListener(new mClick());
    }
    class mClick implements OnClickListener{
        int m_year=2012;
        int m_month=1;
        int m_day=1;
        int m_hour=12,m_minute=1;
        public void onClick(View v){
            if(v==btn1){
                ProgressDialog d=new ProgressDialog(MainActivity.this);
                d.setTitle("进度对话框");
                d.setIndeterminate(true);
                d.setMessage("程序正在Loading...");
                d.setCancelable(true);
                d.setMax(10);
                d.show();
            }else if(v==btn2){

                DatePickerDialog.OnDateSetListener dateListener =new DatePickerDialog.OnDateSetListener(){
                    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth){
                        m_year=year;
                        m_month=monthOfYear;
                        m_day=dayOfMonth;
                        txt.setText(m_year+"/"+(m_month+1)+"/"+m_day);//注意m_year,m_day,m_month是int类型

                    }  };
                DatePickerDialog date=new DatePickerDialog(MainActivity.this,dateListener,m_year,m_month,m_day);
                date.setTitle("日期对话框");
                date.show();


            }else if(v ==btn3){
                TimePickerDialog.OnTimeSetListener timeListener =new TimePickerDialog.OnTimeSetListener(){
                    public void onTimeSet(TimePicker view, int hourOfDay, int minute){
                        m_hour=hourOfDay;
                        m_minute=minute;
                       txt.setText(m_hour+":"+m_minute);
                    }
                };
                TimePickerDialog d=new TimePickerDialog(MainActivity.this,timeListener,m_hour,m_minute,true);
                d.setTitle("时间对话框");
                d.show();

            }
           // txt.setText(m_year+"/"+(m_month+1)+"/"+m_day+" "+m_hour+":"+m_minute);

        }

    }
}

<?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="match_parent"
    tools:context=".MainActivity">
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/button1"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:text="进度对话框"
        android:textSize="18sp"
        />
    <Button
        android:id="@+id/button2"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:text="日期"
        android:textSize="18sp"
        />
    <Button
        android:id="@+id/button3"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:text="选择时间"
        android:textSize="18sp"
        />
    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="显示"
        android:textSize="18sp"
        />
</LinearLayout>

</android.support.constraint.ConstraintLayout>