四种更新UI的方法

笔记：

 

// 使用handler.post(Runnable)更新UI
    public void updateUI_Fun1() {
        new Thread() {
            public void run() {
                Handler handler = new Handler();
                handler.post(new Runnable() {

                    @Override
                    public void run() {
                        textView.setText("this is update content");
                    }
                });
            };
        }.start();
    }

    // 使用handler发送消息更新UI
    public void updateUI_Fun2() {
        Handler handler = new Handler(new Callback() {

            @Override
            public boolean handleMessage(Message msg) {
                // 对handler发送消息的预处理，返回falst则执行下面的handlerMessage() true则不执行

                return false;
            }
        }) {
            public void handleMessage(Message msg) {
                textView.setText("this is update content");
            };
        };
    }

    // 使用UI线程更新UI
    public void updataUI_Fun3() {
        runOnUiThread(new Runnable() {

            @Override
            public void run() {
                textView.setText("updata ui content");
            }
        });
    }

    // 使用View.post( Runnable)更新UI
    public void updateUI_Fun4() {
        textView.post(new Runnable() {

            @Override
            public void run() {
                textView.setText("this is update context");

            }
        });
    }

 

使用子线程自带的Looper更新UI:

代码笔记：

 

private Handler handler2;
    private HandlerThread thread;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        myHandlerThread = (Button) findViewById(R.id.MyThreadHandler);
        handlerThread = (Button) findViewById(R.id.HandlerThread);

        //利用HandlerThread线程执行耗时操作，可以简单代替AsyncTask等。主线程给子线程发送消息
        handlerThread.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                thread=new HandlerThread("aaaa");
                thread.start();
                handler2=new Handler(thread.getLooper()){
                    @Override
                    public void handleMessage(Message msg) {
                        Toast.makeText(SecondActivity.this,    "this is HandlerThread", Toast.LENGTH_SHORT).show();
                    }
                };
                handler2.sendEmptyMessage(1);
            }
        });