作者：刘昊昱

博客：http://blog.csdn.net/liuhaoyutz

本文中我们通过一个例子来看AlertDialog对话框的实现，其运行效果如下：

主布局文件main.xml内容如下：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical" >

    <TextView

        android:id="@+id/textView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textSize="20dp"

        android:text="对话框应用示例：" />"

    <Button

        android:id="@+id/button1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="按钮对话框" />

    <Button

        android:id="@+id/button2"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="列表对话框" />

    <Button

        android:id="@+id/button3"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="单选列表对话框" />

    <Button

        android:id="@+id/button4"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="多选列表对话框" />

</LinearLayout>

布局文件中只是简单的放置了4个按钮。

下面看主Activity文件，其内容如下：

package com.liuhaoyu;

import android.app.Activity;

import android.app.AlertDialog;

import android.app.AlertDialog.Builder;

import android.content.DialogInterface;

import android.content.DialogInterface.OnClickListener;

import android.content.DialogInterface.OnMultiChoiceClickListener;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;

public class MainActivity extends Activity {

	private boolean[] checkedItems;

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        Button button1 = (Button) findViewById(R.id.button1);

		button1.setOnClickListener(new View.OnClickListener() {

			@Override

			public void onClick(View v) {

				AlertDialog alert = new AlertDialog.Builder(MainActivity.this).create();

				alert.setIcon(R.drawable.image01);

				alert.setTitle("按钮对话框：");

				alert.setMessage("带按钮的对话框！");

				alert.setButton(DialogInterface.BUTTON_NEGATIVE,"取消", new OnClickListener() {

					@Override

					public void onClick(DialogInterface dialog, int which) {

						Toast.makeText(MainActivity.this, "您单击了取消按钮",

								Toast.LENGTH_SHORT).show();

					}

				});

				alert.setButton(DialogInterface.BUTTON_POSITIVE,"确定", new OnClickListener() {

					@Override

					public void onClick(DialogInterface dialog, int which) {

						Toast.makeText(MainActivity.this, "您单击了确定按钮",

								Toast.LENGTH_SHORT).show();

					}

				});

				alert.setButton(DialogInterface.BUTTON_NEUTRAL,"中立",new OnClickListener(){

					@Override

					public void onClick(DialogInterface dialog, int which) {

						Toast.makeText(MainActivity.this, "您单击了中立按钮",

								Toast.LENGTH_SHORT).show();

					}

				});

				alert.show();

			}

		});

		Button button2 = (Button) findViewById(R.id.button2);

		button2.setOnClickListener(new View.OnClickListener() {

			@Override

			public void onClick(View v) {

				final String[] items = new String[] { "苹果", "三星", "HTC", "联想", "小米" };

				Builder builder = new AlertDialog.Builder(MainActivity.this);

				builder.setIcon(R.drawable.image01);

				builder.setTitle("请选择手机品牌：");

				builder.setItems(items, new OnClickListener() {

					@Override

					public void onClick(DialogInterface dialog, int which) {

						Toast.makeText(MainActivity.this,

								"您选择了" + items[which], Toast.LENGTH_SHORT).show();

					}

				});

				builder.create().show();

			}

		});

		Button button3 = (Button) findViewById(R.id.button3);

		button3.setOnClickListener(new View.OnClickListener() {

			@Override

			public void onClick(View v) {

				final String[] items = new String[] { "苹果", "三星", "HTC", "联想", "小米" };

				Builder builder = new AlertDialog.Builder(MainActivity.this);

				builder.setIcon(R.drawable.image01);

				builder.setTitle("请选择手机品牌：");

				builder.setSingleChoiceItems(items, 0, new OnClickListener() {

					@Override

					public void onClick(DialogInterface dialog, int which) {

						Toast.makeText(MainActivity.this,

								"您选择了" + items[which], Toast.LENGTH_SHORT).show();

					}

				});

				builder.setPositiveButton("确定", null);

				builder.create().show();

			}

		});

		Button button4 = (Button) findViewById(R.id.button4);

		button4.setOnClickListener(new View.OnClickListener() {

			@Override

			public void onClick(View v) {

				checkedItems= new boolean[] { false, true, false,true, false };

				final String[] items = new String[] { "苹果", "三星", "HTC", "联想", "小米" };

				Builder builder = new AlertDialog.Builder(MainActivity.this);

				builder.setIcon(R.drawable.image01);

				builder.setTitle("请选择手机品牌：");

				builder.setMultiChoiceItems(items, checkedItems,

						new OnMultiChoiceClickListener() {

							@Override

							public void onClick(DialogInterface dialog,

									int which, boolean isChecked) {

								checkedItems[which]=isChecked;

							}

						});

				builder.setPositiveButton("确定", new OnClickListener() {

					@Override

					public void onClick(DialogInterface dialog, int which) {

						String result="";

						for(int i=0;i<checkedItems.length;i++){

							if(checkedItems[i]){

								result+=items[i]+"、";

							}

						}

						if(!"".equals(result)){

							result=result.substring(0, result.length()-1);

							Toast.makeText(MainActivity.this, "您选择了[ "+result+" ]", Toast.LENGTH_LONG).show();

						}

					}

				});

				builder.create().show();

			}

		});

    }

}

程序中为4个按钮设置了点击监听器，在监听器中创建了4种不同的对话框。