public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        try {
            // 主线程阻塞了，为啥运行没有报错？
            Thread.sleep(1000 * 10);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

}

代码亲测过，上面那种情况不会anr，下面这种情况可能会anr。我猜导致这种结果的原因可能是上面的阻塞发生在界面显示之前。

public class MainActivity extends AppCompatActivity {

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

        final Handler handler  = new Handler(){
            public void handleMessage(Message msg){
                try {
                    // 主线程阻塞期间，连续2次点击屏幕会ANR
                    Thread.sleep(1000 * 10);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        };

        Thread t = new Thread() {
            public void run() {
                try {
                    sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                handler.sendEmptyMessage(1);
            }
        };
        t.start();

    }

}