Android学习之多线程开发总结<一>

本文介绍了一种在Android应用中实现UI更新的方法,通过使用Handler与子线程之间的消息传递来完成UI的刷新。文章详细展示了如何定义Handler、Runnable对象,并在不同场景下发送携带数据的消息来更新UI。
    
    private Handler mHandler = new Handler(){
    
        @Override
        public void handleMessage(Message msg) {
            // TODO Auto-generated method stub
            if(nProgressDialog != null && nProgressDialog.isShowing()){
                nProgressDialog.dismiss();
            }
            switch (msg.what) {
            case 1:
                System.out.println("-----------1--------------");
                System.out.println(msg.getData().getString("s1"));
                System.out.println(msg.getData().getString("s2"));
                try {
                    //TODO 
                } catch (Exception e) {
                    e.printStackTrace();
                }
                break;
            case 2:  
                Toast.makeText(getApplicationContext(), "information", Toast.LENGTH_SHORT).show(); 
                break;  
            case 3:  
                Toast.makeText(getApplicationContext(), "information", Toast.LENGTH_SHORT).show(); 
                break;
            default:
                break;
            }
            super.handleMessage(msg);
        }
    };
    
    private Runnable mRunnable = new Runnable() {

        @Override
        public void run() {
            
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
                e.printStackTrace();
            }
            
            //TODO 具体操作
            
            Message msg = new Message();
            msg.what = 0;
            msg.obj = null;
            mHandler.sendMessage(msg);
        }
    };
        
    private Runnable nRunnable = new Runnable() {
    
        @Override
        public void run() {
            // TODO Auto-generated method stub
            String s1 = "fsdfsgfdsgdfgfdgdhshshs";
            String s2 = "fsfsdgdshdhdshrehreherh";

            Message msg = new Message();
            msg.what = 1;
            Bundle bundle = new Bundle();
            bundle.putString("s1", s1);
            bundle.putString("s2", s2);
            msg.setData(bundle);
            MainActivity.this.mHandler.sendMessage(msg);
        }
    };
    
    //如何调用
    ProgressDialog nProgressDialog = ProgressDialog.show(MainActivity.this, "正在查询", "操作需要稍长时间,请耐心等待!");
    Thread thread = new Thread(mRunnable);
    thread.start();
    thread = null;
    
    //创建一个新的线程来执行xxx等相应操作
    new Thread(new Runnable() {
        
        @Override
        public void run() {
            try {
                //更新UI
                String mInfo = "information\n";
                mHandler.sendMessage(mHandler.obtainMessage(0, mInfo));
            } catch (Exception e) {
                e.printStackTrace();
            }
            
        }
    }).start();
    
    private class mThread extends Thread{
        public void run() {
            // TODO Auto-generated method stub
            String s1 = "fsdfsgfdsgdfgfdgdhshshs";
            String s2 = "fsfsdgdshdhdshrehreherh";
 
            Message msg = new Message();
            msg.what = 1;
            Bundle bundle = new Bundle();
            bundle.putString("s1", s1);
            bundle.putString("s2", s2);
            msg.setData(bundle);
            MainActivity.this.mHandler.sendMessage(msg);
        }
    }
    
    //如何调用
    ProgressDialog nProgressDialog = ProgressDialog.show(MainActivity.this, "正在查询", "操作需要稍长时间,请耐心等待!");
    mThread thread = new mThread();
    thread.start();
    thread = null;
    
    //注意以下区别
    Message msg = new Message();
    msg.what = 0;
    msg.obj = null;
    mHandler.sendMessage(msg);
    
    Message msg = mHandler.obtainMessage();
    msg.what = xxx;
    msg.arg1 = xxx;
    msg.arg2 = xxx;
    msg.obj = xxx;
    msg.sendToTarget();
    
    //For example
    mHandler.obtainMessage(0, arg1, -1).sendToTarget();

 

转载于:https://www.cnblogs.com/shuaiwen/p/3499026.html

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