努力从 Thread 更新我的 UI

Question

我已经尝试过 AsyncTask、Handler 和一个简单的线程来实现我想要做的事情，但我无法让它们中的任何一个工作，下面是我需要用来更新我的 UI 的逻辑......

public class GameProcessor extends Thread {

@Override
public void run() {

    for (Integer integer : sequence) {

        //set button state to pressed
        Console.getBottomLeft().getButton().setBackgroundResource(R.drawable.button_focused);

        try {
            sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        //set button state to un-pressed

        try {
            sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

    try {
        sleep(1000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }


}

}

请不要回复，除了主线程之外，您无法从任何地方更新 UI，我已经知道这一点，并且需要一个解决方案来解决如何在更新 UI 的同时从后端循环一些值。据我所知， AsyncTask 和 Handler 不会有太大帮助。

任何帮助将不胜感激！

Answer 1

如果您了解 UI 线程，为什么不知道：

runOnUiThread(new Runnable() {
    public void run() {
        //set button state to un-pressed or pressed.. or whatever you want..
    }
});

我不明白你的问题

Answer 2

在您的 Activity (mHandler) 中创建一个成员 Handler 对象。每当你想从另一个线程更新你的 UI 时，调用

mHandler.post(new Runnable(){
    public void run(){
        //update the button state
    }
});

Handler 会在 UI 线程中为你调用这个 run() 方法。

这是简化的。您可能希望将 Runnables 创建为成员变量，这样您就不会一遍又一遍地重新创建相同的 Runnables。

Answer 3

    If you want to loop through some valuse, while updating the UI at the same time, then you may consider using AsyncTask and may use this feature:

    protected void onProgressUpdate(Integer... progress) {
             setProgressPercent(progress[0]);
         }

    And from :
    protected Long doInBackground(URL... urls) {
                 calculate value
                 publishProgress(value);
              return totalSize;
         }

    This will keep on updating UI thread with intermediate values you send.

    In case you already know this and have tried and it does not solve your purpose, am sorry :)

or you can try this:

公共无效运行（）{

        Console.post(new Runnable() {
            public void run() {
                Console.getBottomLeft().getButton().setBackgroundResource(R.drawable.button_focused);
            }
        });
    }

Answer 4

为了更新您的 UI 线程，您可以使用处理程序。下面是一个使用 AsyncTask 和 Handler 的简单示例：

    private static final String MESSAGE_KEY = "com.example.mypackage.MSGKEY";
    private static final int MESSAGE_AUTHENTICATING = 0;
    private static final int MESSAGE_AUTHENTICATED = 1;

    /**
     * This handler will update UI 
     * 
     */
    private final Handler handler = new Handler() {
        public void handleMessage(Message msg) {
            switch (msg.getData().getInt(MESSAGE_KEY)) {
            case MESSAGE_AUTHENTICATING:
                hashstream_stream.setVisibility(View.GONE);
                hashstream_progress.setVisibility(View.VISIBLE);
                break;
            case MESSAGE_AUTHENTICATED:
                hashstream_stream.setVisibility(View.VISIBLE);
                hashstream_progress.setVisibility(View.GONE);
                break;
            default:
                break;

            }
        }
    };

    /**
    * This method should be used to update UI thread.
    * 
    * @param value
    */
    private void postMessage(int value) {
        Message msgObj = handler.obtainMessage();
        Bundle bundle = new Bundle();
        bundle.putInt(MESSAGE_KEY, value);
        msgObj.setData(bundle);
        handler.sendMessage(msgObj);
    }

    /**
     * AsyncTask Helper class as network op
     * 
     * 
     */
    private class StreamHashTagTask extends AsyncTask<Void, Void, Void> {

        @Override
        protected Void doInBackground(Void... params) {

            //Do actual operation in here

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);

            postMessage(MESSAGE_AUTHENTICATED);
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();

            postMessage(MESSAGE_AUTHENTICATING);
        }

        /**
         * If you need to update progress override onProgressUpdate() method.
         * Since I am indeterminate using progress bar as authentication time
         * cannot be calculated , I don't need update here
         */

    }

Answer 5

你试过了吗？

instanceOfActivity.runOnUiThread(new Runnable(){
    @Override
    public void run() {
        Console.getBottomLeft().getButton().setBackgroundResource(R.drawable.button_focused);
    }
});

但在这种情况下，我不建议您在另一个对象中使用活动。

请使用上述界面：

public interface INotifyChange {
     void notify(object value); // Example: void notify(int progress);
}

在您调用 GameProcessor

的活动中

INotifychange mNotifier;

mNotifier = new INotifyChange() {
    @Override
    public void notify(object value) {
        runOnUiThread(new Runnable(){
            @Override
            public void run() {
                //You can update your UI here.
            }
        });
    }
};

// 还有你的GameProcessor

private INotifyChange mNotifier;
public GameProcessor(INotifyChange aNotifier) {
    mNotifier = aNotifier;
}

//要更新UI的地方，请调用

mNotifier.notify(value);