Android 错误：只有创建视图层次结构的原始线程才能触摸其视图

Question

得到一个错误：android.view.ViewRootImpl$CalledFromWrongThreadException：只有创建视图层次结构的原始线程可以触摸它的视图。
我真的不知道为什么。

  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button generate = (Button) findViewById(R.id.gen);
    final TextView dice1 = (TextView) findViewById(R.id.dice1);
    final TextView dice2 = (TextView) findViewById(R.id.dice2);
    final TextView dice3 = (TextView) findViewById(R.id.dice3);


    generate.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {           
            dice1.setText(" ");
            dice2.setText(" ");
            dice3.setText(" ");         
            Thread thread = new Thread()
            {
                @Override
                public void run() {
                    try {
                        while(true) {
                            sleep(2000);
                            setText("lol", "lol", "lol");
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            };
            thread.start();             
        }

    });
}
public void setText(String d1, String d2, String d3){
    dice1.setText(d1);
    dice2.setText(d2);
    dice3.setText(d3);  
}

谢谢你的帮助。

Answer 1

你有这个错误是因为你在另一个线程而不是 UI 线程中操作视图。您的setText方法修改了 3 个 TextViews ( dice1, dice2, dice3)的文本。

你应该runOnUiThread像这样调用这个方法：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button generate = (Button) findViewById(R.id.gen);
    final TextView dice1 = (TextView) findViewById(R.id.dice1);
    final TextView dice2 = (TextView) findViewById(R.id.dice2);
    final TextView dice3 = (TextView) findViewById(R.id.dice3);

    generate.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {           
            dice1.setText(" ");
            dice2.setText(" ");
            dice3.setText(" ");         
            Thread thread = new Thread()
            {
                @Override
                public void run() {
                    try {
                        while(true) {
                            sleep(2000);
                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    setText("lol", "lol", "lol");
                                }
                            });
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            };
            thread.start();             
        }

    });
}
public void setText(String d1, String d2, String d3){
    dice1.setText(d1);
    dice2.setText(d2);
    dice3.setText(d3);  
}