android - MyLinearLayout.getDrawingCache() 给出 NullPointerException

Question

编辑：

没关系，让它这样工作

TopRatedPage.setDrawingCacheEnabled(true);
TopRatedPage.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
TopRatedPage.layout(0, 0, TopRatedPage.getMeasuredWidth(), TopRatedPage.getMeasuredHeight()); 
TopRatedPage.buildDrawingCache(true);
Bitmap screenshot = Bitmap.createBitmap(TopRatedPage.getDrawingCache());
TopRatedPage.setDrawingCacheEnabled(false);

---

老的：

我正在尝试从布局中截取屏幕截图，就像这样。

LinearLayout TopRatedPage = (LinearLayout)inflater.inflate(R.layout.toprated, null);
...
Bitmap screenshot;
TopRatedPage.setDrawingCacheEnabled(true);
screenshot = Bitmap.createBitmap(TopRatedPage.getDrawingCache()); // Caused by: java.lang.NullPointerException
TopRatedPage.setDrawingCacheEnabled(false);

任何想法我做错了什么？

谢谢！

编辑：也试过这样，它不会抛出错误，但给出一个空位图。

Bitmap screenshot = TopRatedPage.getDrawingCache();

Answer 1

试试这个，让我知道会发生什么..

LinearLayout TopRatedPage = (LinearLayout)inflater.inflate(R.layout.toprated, null);
Bitmap screenshot = Bitmap.createBitmap(LinearLayout .getWidth(), LinearLayout .getHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(screenshot);
LinearLayout.draw(c);
imageView.setImageBitmap(screenshot);

如果可能的话，使用，

View captureView = null;
captureView = inflater.inflate(R.layout.toprated, null);
Bitmap screenshot = Bitmap.createBitmap(captureView.getWidth(), captureView.getHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(screenshot);
captureView .draw(c);
imageView.setImageBitmap(screenshot);