启用滚动时调用 `getDrawingCache` 返回 null [英] Call to `getDrawingCache` returns null when scroll is enabled

问题描述

这段代码缺少什么?相同的代码适用于 ICS.在 API 8 上，滚动出现并且一些内容超出屏幕.这种情况下如何获取绘图缓存?

What is missing in this code? This same code works on ICS. On API 8 the scroll appears and some content goes out of screen. How to get the drawing cache in this case?

代码:

TableLayout page = (TableLayout) findViewById(R.id.page);
page.setDrawingCacheEnabled(true);
page.buildDrawingCache();

// getDrawingCache returns null...
Bitmap pageBmp = Bitmap.createBitmap(page.getDrawingCache(true));
page.destroyDrawingCache();
page.setDrawingCacheEnabled(false);

推荐答案

我解决了.创建视图大小的位图并将视图绘制到其中.

I solved it. Created a bitmap of view size and drew the view into it.

TableLayout page = (TableLayout) findViewById(R.id.page);
Bitmap pageBmp = Bitmap.createBitmap(page.getWidth(), page.getHeight(), 
                                       Config.ARGB_8888);
Canvas canvas = new Canvas(pageBmp);
page.draw(canvas);

使用了 pageBmp 位图..

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