Android在Activity中启动一个新进程报错：Can't create handler inside thread that has not called Looper.prepare()。

现象：

在Activity中启动一个新进程报错:Can't create handler inside thread that has not called Looper.prepare()。

源码:

		button.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
				dialog.setTitle("进度对话框");
				dialog.setMessage( "正在加载，请稍后...");
				dialog.show();////显示进度对话框
				new Thread()
				{
					public void run() {
						try {
							sleep(1000);
						} catch (InterruptedException e) {
							e.printStackTrace();
						}
						dialog.dismiss();
					};
				}.start();
			}
		});

分析：

一般在非 UI 的线程中不允许调弹出带或者关闭对话框之类的

解决方法：

方法一、将 代码块放到Looper.prepare();和Looper.loop();中间运行

public void onClick(View v) {
				// TODO Auto-generated method stub
				final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
				dialog.setTitle("进度对话框");
				dialog.setMessage( "正在加载，请稍后...");
				dialog.show();////显示进度对话框
				new Thread()
				{
					public void run() {
						Looper.prepare();
						try {
							sleep(1000);
						} catch (InterruptedException e) {
							e.printStackTrace();
						}
						dialog.dismiss();
						Looper.loop();
					};
				}.start();
			}
		});

方法二、将代码块放到主线程的 UiThread中运行

		button.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				final ProgressDialog dialog = new ProgressDialog(MainActivity.this);
				dialog.setTitle("进度对话框");
				dialog.setMessage( "正在加载，请稍后...");
				dialog.show();////显示进度对话框
				new Thread()
				{
					public void run() {
						try {
							sleep(1000);
						} catch (InterruptedException e) {
							e.printStackTrace();
						}
						
						MainActivity.this.runOnUiThread(new Runnable() {  
                            @Override  
                            public void run() {  
                            	dialog.dismiss();
                            }  
                        });
						
					};
				}.start();
			}
		});