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：