Android-03:简单进度条的使用

演示简单的进度条，这里启了一个线程来做一些耗时较长的操作，防止activity死掉：

 

public class ProgressBarDemo extends Activity {
    // 进度条
    ProgressDialog pd = null;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 显示进度条
        pd = ProgressDialog.show(ProgressBarDemo.this, "请稍后", "正在读取证书列表…");
        //新建线程  
        new Thread(){ 
            @Override  
            public void run() {  
                // Do something

                // 向handler发消息  
                handler.sendEmptyMessage(0);  
            }}.start();
    }
    private Handler handler = new Handler(){  
        
        @Override  
        public void handleMessage(Message msg) {  
            // thread finished
            //关闭ProgressDialog  
            pd.dismiss();
    }}