Android

MainActivity.java

package com.example.zc.alertdialog;

import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private Button mButton;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        mButton = (Button) findViewById(R.id.button);//引用已生成的组件
        mButton.setOnClickListener(
                new View.OnClickListener()
                {
                    @Override
                    public void onClick(View v)
                    {
                        //Alert1();
                        //Alert2();
                        Alert3();
                    }
                }
        );



    }

    public void Alert1()
    {
        new AlertDialog.Builder(this)
                .setTitle("Android 提示")
                .setMessage("这是一个提示,请确定")
                .show();
    }
    public void Alert2()
    {
        new AlertDialog.Builder(this)
                .setMessage("这是第二个提示")
                .setPositiveButton("确定",
                        new DialogInterface.OnClickListener(){
                            public void onClick(DialogInterface dialoginterface, int i){
                                //按钮事件
                            }
                        })
                .show();
    }
    public void Alert3()
    {
        new AlertDialog.Builder(this)
                .setTitle("提示")
                .setMessage("确定退出?")
                //.setIcon(R.drawable.quit)
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        setResult(RESULT_OK);//确定按钮事件
                        finish();
                    }
                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int whichButton) {
                        //取消按钮事件
                    }
                })
                .show();
    }



}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical"
    >

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="hello"
        android:layout_gravity="center"
        />

</LinearLayout>