Handlerの使用解析

6653 ワード

HandlerにはPostとsendMessageの2つの使い方があります.
义齿

post(Runnable r):一般的なpost方式.

postAtTime(Runnable r,long uptimeMillis):ある絶対時間に

を実行するように設定

postAtTime(Runnable r, Object token, long uptimeMillis)

postDelayed(Runnable r,long delayMillis):実行遅延時間を設定して

を実行
Handlerを決める

private Handler mPostHandler = new Handler();

サブスレッドを作成:

private class TestThread extends Thread{
    @Override
    public void run() {

        try {
            Thread.sleep(5000);


            /**
             * Post     Runnable          .
             *    ：
             * post(Runnable)
             * postAtTime(Runnable,long)
             * postDelayed(Runnable,long)
             *
             *   Handler Post    ，      Runnable        ，   Runnable   ，  run()  。     run()        UI      。
             */
            mPostHandler.post(new Runnable() {
                @Override
                public void run() {
                    text.setText("Handler Post      ");
                    LogHelper.i("Handler Post      ");
                }
            });

            /**
             * postAtTime:              。
             */
            mPostHandler.postAtTime(new Runnable() {
                @Override
                public void run() {
                    text.setText(text.getText().toString()+"
 Handler postAtTime      ");
                    LogHelper.i("Handler postAtTime      ");
                }
            }, SystemClock.uptimeMillis() + 5000);

            /**
             * postDelayed:    .
             */
            mPostHandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    text.setText(text.getText().toString()+"
 Handler postDelayed      ");
                    LogHelper.i("Handler postDelayed      ");
                }
            },1000);



        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

sendMessage方式
まずHandlerでMessageを処理します.

sendMessage(Message msg):

sendMessageDelayed(Message msg, long delayMillis):

sendMessageAtTime(Message msg, long uptimeMillis) :

sendEmptyMessage(int what)

sendEmptyMessageDelayed(int what, long delayMillis)

sendEmptyMessageAtTime(int what, long uptimeMillis) : private Handler mHandler = new Handler(){

  @Override
  public void handleMessage(Message msg) {
      switch (msg.what){
          case MSG_ONE:
              String obj = (String)msg.obj;
              LogHelper.i("
 obj is : " + obj);
              text.setText(text.getText().toString()+"obj is : " + obj);

              int arg1 = msg.arg1;
              int arg2 = msg.arg2;
              LogHelper.i("
 arg1 is : " + arg1 + " arg2 is : " + arg2);
              text.setText(text.getText().toString()+"arg1 is : " + arg1 + " arg2 is : " + arg2);

              if(msg.getData() != null){
                 String test =  (String)msg.getData().get("test");
                  LogHelper.i("
 test is : " + test);
                  text.setText(text.getText().toString()+"test is : " + test);
              }
              break;
          case MSG_TWO:
              LogHelper.i("receive  MSG_TWO ");
              break;
      }
  }

};

サブスレッドの作成

private class TestMessageThread extends Thread {
    @Override
    public void run() {

        try {
            Thread.sleep(5000);

            /**
             *  3     Message：
             *
             * 1、Message message = new Message();
             * 2、Message message = Message.obtain();
             * 3、Message message = mHandler.obtainMessage();
             *
             */
            Message message = Message.obtain();

            /**
             * what         Message    ，    Handler handleMessage     what      Message，             
             */
            message.what = MSG_ONE;

            /**
             *     arg1 arg2 Message       
             */
            message.arg1 = 100;
            message.arg2 = 101;

            /**
             *      obj  Object     Message      
             */
            message.obj = new String("Obj String");

            /**
             *   setData   getData   Message      Bundle     
             */
            Bundle bundle = new Bundle();
            bundle.putString("test","test string");
            message.setData(bundle);

            mCallHandler.sendMessage(message);
            /**
             *      。
             */
            mCallHandler.sendEmptyMessage(MSG_TWO);

            /**
             *              。
             */
            mHandler.sendMessageAtTime(message,SystemClock.uptimeMillis() + 5000);

            /**
             *     
             */
            mHandler.sendMessageDelayed(message,1000);

        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }
}

HandlerにはCallback付きの構造関数もあります.

/**
 * Callback         true，      ，      false，         handleMessage，       .
 */
private Handler mCallHandler = new Handler(new Handler.Callback() {
    @Override
    public boolean handleMessage(Message msg) {
        if(msg.what == MSG_TWO){
            LogHelper.i("Callback  MSG_TWO ");
            return true;
        }
        return false;
    }
}){
    @Override
    public void handleMessage(Message msg) {
        switch (msg.what){
            case MSG_ONE:
                String obj = (String)msg.obj;
                LogHelper.i("
 obj is : " + obj);
                text.setText(text.getText().toString()+"obj is : " + obj);

                int arg1 = msg.arg1;
                int arg2 = msg.arg2;
                LogHelper.i("
 arg1 is : " + arg1 + " arg2 is : " + arg2);
                text.setText(text.getText().toString()+"arg1 is : " + arg1 + " arg2 is : " + arg2);

                if(msg.getData() != null){
                    String test =  (String)msg.getData().get("test");
                    LogHelper.i("
 test is : " + test);
                    text.setText(text.getText().toString()+"test is : " + test);
                }
                break;
            case MSG_TWO:
                LogHelper.i("receive  MSG_TWO ");
                break;
        }
    }
};

iOSは、画面に対するコントロールの位置を取得します.

Mongoコマンドとか初心者が苦しんだ所を書き残す。