Android应用开发学习之AlertDialog对话框

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:andro
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView 
        android:
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="对话框应用示例：" />"
    
    <Button
        android:
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="按钮对话框" />

    <Button
        android:
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="列表对话框" />

    <Button
        android:
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="单选列表对话框" />

    <Button
        android:
        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。