Android线程、处理程序、HandleMessage：从外部类文件中的可运行线程更新UI线程

Question

背景：我正在尝试转换一个Java（非GUI）程序来运行在Android上。为了简单起见，假设这个程序有以下文件：

java,sinfer.java,main.java

public class MainActivity extends Activity {

    /* UI Elements */
    private TextView output;

    /* Thread Handler */
    private Handler uiHandler;

    /* Handle message override */
    public class UIHandler extends Handler {

        @Override
        public void handleMessage(Message msg) {
            output.append(msg.obj.toString());
            super.handleMessage(msg);
        }
    }

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

        output = (TextView) findViewById(R.id.displayTextView);
        uiHandler = new UIHandler();

        setStartButtonClickListener();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_run_fsi, menu);
        return true;
    }


    private void setStartButtonClickListener() {
        Button startButton = (Button) findViewById(R.id.startButton);
        startButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                runFSI();

            }
        });
    }

    private void runFSI() {
        // initialize SInfer and pass uiHandler

        SInfer inferer = SInfer.getInstance(/*other variables*/, uiHandler);


        // initialize DSGen
        DSGenerator dsGen;

        Thread t1 = new Thread(dsGen);
        Thread t2 = new Thread(inferer);
        t1.start();
        t1.yield();
        t2.start();
        t2.yield();

        try {
            Thread.sleep(10000);
        } catch (Exception e) {
        }

        inferer.stop();
        dsGen.stop();

    }

}

SInfer内部定义的run方法如下（System.out代码是从原始Java代码中遗留下来的）

@Override
public void run() {

    // System.out.println("Inference: Thread started...");

    while (stopFlag == false) {
        try {
            // System.out.println("SInference: run.........");
            Thread.sleep(200);
            inferenceResult = doInference();

            /* Send result to UI thread */

            Message msg = Message.obtain(uiHandler);
            msg.obj = inferenceResult.toString();
            uiHandler.sendMessage(msg);

        } catch (InterruptedException e) {
            // System.out.println(e.getMessage());
        }
    }
}

Answer 1

您正在运行Thread.Sleep（10000）；在主线程中（OnClick在UI线程中调用），所以在这10秒内UI中什么都不能更新。尝试在单独的线程中调用runFSI方法。