Android—对话框

layout文件：

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="com.hanqi.testapp2.TestActivity5"
     android:orientation="vertical">

     <Button
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="一般对话框"
         android:onClick="bt1_onClick"/>
     <Button
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:onClick="bt2_onClick"
         android:text="单选对话框"/>
     <Button
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:onClick="bt3_onClick"
         android:text="复选对话框"/>
 </LinearLayout>

java类代码：

 package com.hanqi.testapp2;

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

 public class TestActivity5 extends AppCompatActivity {

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_test5);
     }
     //一般对话框
     public void bt1_onClick(View v)
     {
         //对话框不能直接实例化
         //内部提供了构造器
         //方法链调用
         AlertDialog alertDialog = new AlertDialog.Builder(this)
                 .setTitle("确认对话框")
                 .setMessage("确实要删除么")
                 .setPositiveButton("确认", new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
                         Toast.makeText(TestActivity5.this, "执行删除，which = " + which, Toast.LENGTH_SHORT).show();
                     }
                 })//正面按钮
                 .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
                         Toast.makeText(TestActivity5.this, "取消删除，which = " + which, Toast.LENGTH_SHORT).show();
                     }
                 })
                 .setNeutralButton("中立", new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
                         Toast.makeText(TestActivity5.this, "按钮，which = " + which, Toast.LENGTH_SHORT).show();
                     }
                 }).setCancelable(false)
                 .show();//显示对话框
     }
     //单选对话框
     public void bt2_onClick(View v)
     {
         //final可以让常量的生命周期延长到整个实例
         final String [] str = {"男","女"};
         new AlertDialog.Builder(this)
                 .setTitle("单选对话框")
                 .setSingleChoiceItems(str, 0, new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
                         Toast.makeText(TestActivity5.this, "which = "+which+
                                 "，选中的是"+str[which], Toast.LENGTH_SHORT).show();
                         //关闭对话框
                         dialog.dismiss();
                     }
                 }).setCancelable(false)
                 .show();
     }
     //复选对话框
     public void bt3_onClick(View v)
     {
         final String [] str = {"宝马","奔驰","劳斯莱斯","宾利"};
         final boolean[] ch = {true,false,false,true};
         new AlertDialog.Builder(this)
                 .setTitle("复选对话框")
                 .setMultiChoiceItems(str, ch, new DialogInterface.OnMultiChoiceClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                         //改变对应数组项的选中状态
                         ch[which] = isChecked;
                     }
                 })
                 .setPositiveButton("确认", new DialogInterface.OnClickListener() {
                     @Override
                     public void onClick(DialogInterface dialog, int which) {
                         int i = 0;
                         //获取最终的选中状态
                         for (boolean b:ch)
                         {
                             Toast.makeText(TestActivity5.this, str[i]+"选中状态 = "+
                                     (b?"选中":"未选中"), Toast.LENGTH_SHORT).show();
                             i++;
                         }
                     }
                 })
                 .setNegativeButton("取消", null)
                 .setCancelable(false)
                 .show();
     }
 }

效果图：