Question

我要做的是让我的程序在更改图像之前等待3秒钟。我做了我的研究，似乎这可以解决它，但它告诉我，我需要让c1和c2最终。但是，这会破坏我的其余代码。

我试图在3秒后运行这两行：

c1.getImg().setImageResource(R.drawable.facedown);
c2.getImg().setImageResource(R.drawable.facedown);

这是什么解决方案？谢谢！

private Thread thread;

public void checkMatch(int num) {
    flips++;
    President c1 = null;
    President c2 = cards.get(num - 1);
    if (flips % 2 != 0) {
        return;
    } else {
        for (President c : cards) {
            if (c.isFlipped() == true && c.isMatched() == false && c != c2) {
                c1 = c;
            }
        }

        if (c1.getPresident() == c2.getPresident()) {
            cards.get(c1.getCard() - 1).setMatched(true);
            cards.get(c2.getCard() - 1).setMatched(true);
        } else {

            cards.get(c1.getCard() - 1).setFlipped(false);
            cards.get(c2.getCard() - 1).setFlipped(false);

             thread = new Thread() {
             @Override
             public void run() {
             try {
             synchronized (this) {
             wait(3000);
             }
             } catch (InterruptedException ex) {
             }

             // TODO
//THESE TWO LINES ARE THE ONES I WANT TO RUN AFTER 3 SECONDS
                    c1.getImg().setImageResource(R.drawable.facedown);
                    c2.getImg().setImageResource(R.drawable.facedown);
             }
             };

             thread.start();
        }
    }
}

 @Override
 public boolean onTouchEvent(MotionEvent evt) {
 if (evt.getAction() == MotionEvent.ACTION_DOWN) {
 synchronized (thread) {
 thread.notifyAll();
 }
 }
 return true;
 }

09-07 17:04:19.937: E/AndroidRuntime(6822): FATAL EXCEPTION: Thread-4693
09-07 17:04:19.937: E/AndroidRuntime(6822): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:4746)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:823)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.View.requestLayout(View.java:15473)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.View.requestLayout(View.java:15473)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.View.requestLayout(View.java:15473)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.View.requestLayout(View.java:15473)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.widget.RelativeLayout.requestLayout(RelativeLayout.java:318)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.view.View.requestLayout(View.java:15473)
09-07 17:04:19.937: E/AndroidRuntime(6822):     at android.widget.ImageView.setImageResource(ImageView.java:352)

Answer 1

将c1和c2声明为全局变量。

private Thread thread;

President c1, c2;

public void checkMatch(int num) {
    flips++;
    c1 = null;
    c2 = cards.get(num - 1);
    ....
    ....
}

修改

您正在尝试从非UI线程更改UI。而不是以下：

thread = new Thread() { @Override public void run() { try { synchronized (this) { wait(3000); } } catch (InterruptedException ex) { } // TODO //THESE TWO LINES ARE THE ONES I WANT TO RUN AFTER 3 SECONDS c1.getImg().setImageResource(R.drawable.facedown); c2.getImg().setImageResource(R.drawable.facedown); } }; thread.start();

使用处理程序：

new Handler().postDelayed(new Runnable() { @Override public void run() { c1.getImg().setImageResource(R.drawable.facedown); c2.getImg().setImageResource(R.drawable.facedown); } }, 3000L);

在没有最终的情况下继续等待3秒

1 个答案: