Android Handler和HandlerThread使用方法

Handler的官方注释如下:

A Handler allows you to send and process <a href="file:///F:/android%E5%AD%A6%E4%B9%A0/docs-3.0_r01-linux/docs/reference/android/os/Message.html">Message</a> and Runnable objects associated with a thread’s <a href="file:///F:/android%E5%AD%A6%E4%B9%A0/docs-3.0_r01-linux/docs/reference/android/os/MessageQueue.html">MessageQueue</a>. Each Handler instance is associated with a single thread and that thread’s message queue. Handler会关联一个单独的线程和消息队列。Handler默认关联主线程,虽然要提供Runnable参数 ,但默认是直接调用Runnable中的run()方法。也就是默认下会在主线程执行,如果在这里面的操作会有阻塞,界面也会卡住。如果要在其他线程执行,可以使用HandlerThread。

Handler使用方法:

Handler handler = new Handler() {

			@Override
			public void handleMessage(Message msg) {
				// 处理发送过来的消息
				Bundle b = msg.getData();
				System.out.println("msg:" + msg.arg1);
				System.out.println("msg:" + b.getString("name") + " - age:" + b.getInt("age"));
				super.handleMessage(msg);
			}

        };

        Message msg = handler.obtainMessage();
        msg.arg1 = 121;
        Bundle b = new Bundle();
        b.putInt("age", 24);
        b.putString("name", "Fatkun");
        msg.setData(b);
        msg.sendToTarget();

        handler.post(r);

    }

    Runnable r = new Runnable() {

		public void run() {
			try {
                                // 在这里只是睡一下
				Thread.sleep(10000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}

		}
	};

HandlerThread使用方法:

//把上面创建Handler的代码
Handler handler = new Handler() {
...
}

//改为:
HandlerThread thread = new HandlerThread("athread");
thread.start(); //要把线程启动
        
Handler handler = new Handler(thread.getLooper()) {
...
}

参考:

Android中的Handler, Looper, MessageQueue和Thread的关系

updatedupdated2023-12-062023-12-06