Question

对于特定的线程，我有以下代码

public void run() {

    while (true) {
        currentWord = words.get(new Random().nextInt(words.size()));
        tvForeignWord.setText(currentWord.getWordForeign());
        tvScore.setText("Your score is " + score);
        for (int i = timer_length; i > 0; i--) {
            tvTimer.setText("You have " + i + " seconds remaining.");
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                //DEBUG e.printStackTrace();
            }
        }
    }
}

但是，我似乎收到此错误消息：

02-19 22:03:38.950: E/AndroidRuntime(17236): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

问题是什么？

当我这样做时：

public void run() {

    //while (true) {
        currentWord = words.get(new Random().nextInt(words.size()));
        tvForeignWord.setText(currentWord.getWordForeign());
        tvScore.setText("Your score is " + score);
        //for (int i = timer_length; i > 0; i--) {
            //tvTimer.setText("You have " + i + " seconds remaining.");
            //try {
                //Thread.sleep(1000);
            //} catch (InterruptedException e) {
                //DEBUG e.printStackTrace();
            //}
        //}
    }

我没有错误？

Answer 1

您不应该从单独的线程更新UI。在线程外部创建一个Handler对象并将runnables发布到该对象，或者尝试使用context.runOnUiThread（）在主线程上执行UI操作。

Answer 2

只允许UI线程操纵UI对象。您需要在UI线程和工作线程之间设置消息传递，以便工作线程在屏幕上产生更改。

不明白为什么线程在Android中发生变化？

2 个答案: