package com.andli.handlerandthread;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;

public class HandlerAndThreadActivity extends Activity {
	private String tag = "andli";

	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		Log.i(tag, "---------------Main------------------");
		Log.i(tag, "Thread_ID=" + Thread.currentThread().getId());
		Log.i(tag, "Thread_Name=" + Thread.currentThread().getName());

		Handler handler = new Handler();
		Log.i(tag, "--------------Handler_Thread----------");
		handler.post(runnable);

		Log.i(tag, "---------------Thread------------------");
		Thread thread = new Thread(runnable);
		thread.start();

	}

	Runnable runnable = new Runnable() {
		public void run() {
			Log.i(tag, "Thread_ID=" + Thread.currentThread().getId());
			Log.i(tag, "Thread_Name=" + Thread.currentThread().getName());
		}
	};
}

package com.lilin.handler;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ImageView;

/**
 * 通过Handler实现2秒自动换图
 * 
 * @author lilin
 * @date 2011-8-10 上午08:51:27
 * @ClassName: Main
 * @Description: TODO
 */
public class Main extends Activity {
	ImageView myImageView;// ImageView的引用

	public void onCreate(Bundle savedInstanceState) {// 重写的onCreate方法
		super.onCreate(savedInstanceState);
		setTitle("handler通信：每2秒自动换图");
		setContentView(R.layout.main);// 设置当前的用户界面

		
		System.out
				.println("当前activity的ID--->" + Thread.currentThread().getId());
		System.out.println("当前activity的名称--->"
				+ Thread.currentThread().getName());

		myImageView = (ImageView) findViewById(R.id.myImageView);

		new Thread() {
			public void run() {
				int i = 0;
				while (true) {// 循环
					myHandler.sendEmptyMessage((i++) % 4);// 发送消息
					System.out.println("handler的ID--->"
							+ Thread.currentThread().getId());
					System.out.println("handler的名称--->"
							+ Thread.currentThread().getName());
					try {
						Thread.sleep(2000);
					} catch (Exception e) {
						e.printStackTrace();
					}
				}

			};
		}.start();
	}

	Handler myHandler = new Handler() {// 创建一个Handler对象
		public void handleMessage(Message msg) {// 重写接收消息的方法
			switch (msg.what) {// 判断what的值
			case 0:// what值为0时
				myImageView.setImageResource(R.drawable.bbta);
				break;
			case 1:// what值为1时
				myImageView.setImageResource(R.drawable.bbtb);
				break;
			case 2:// what值为2时
				myImageView.setImageResource(R.drawable.bbtc);
				break;
			case 3:// what值为3时
				myImageView.setImageResource(R.drawable.bbtd);
				break;
			}
			super.handleMessage(msg);
		}
	};
}

头文件：

#import <UIKit/UIKit.h>

@interface AlertViewController : UIViewController <UIWebViewDelegate> {
	UIWebView *webView;
	UIAlertView *alert; 
}

@property (nonatomic, retain) IBOutlet UIWebView *webView;
@property (nonatomic, retain) UIAlertView *alert; 

- (void) NavURL;

@end

实现文件：

#import "AlertViewController.h"

@implementation AlertViewController

@synthesize webView, alert;

-(void) NavURL{
	[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://2015.iteye.com"]]];
}

- (void)webViewDidStartLoad:(UIWebView *)webView {
	if (alert == nil){                
		alert = [[UIAlertView alloc] initWithTitle: nil
																			 message: @"正在读取网络数据"
																			delegate: self
														 cancelButtonTitle: nil
														 otherButtonTitles: nil];
	}
	UIActivityIndicatorView *activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
	activityView.frame = CGRectMake(120.f, 48.0f, 37.0f, 37.0f);
	[alert addSubview:activityView];
	[activityView startAnimating];
	[activityView release];
	[alert show];
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
	[alert dismissWithClickedButtonIndex:0 animated:YES];
}

- (void)viewDidLoad {
	[super viewDidLoad];
	[self NavURL];
}

- (void)dealloc {
	[super dealloc];
	[webView release];
	[alert release];
	webView = nil;
	alert = nil;
}

@end

示例图：