立即更改子视图的可见性时更新android视图

Question

I have an view, that is a RelativeLayout. Inside that layout, there is an image, that has visibility set to gone by default. What I want to achieve is to change visibility to visible programmatically and after that make a view snapshot, draw it to canvas.

    View icon = v.findViewById(android.R.id.icon2);
    if (icon != null) {
        icon.setVisibility(View.VISIBLE);
        v.invalidate();
        v.forceLayout();
        icon.invalidate();
        icon.refreshDrawableState();
    }

....

    v.setDrawingCacheEnabled(true);
    mFloatBitmap = Bitmap.createBitmap(v.getDrawingCache());
    v.setDrawingCacheEnabled(false);

The resulting bitmap does not contain changes icon.setVisibility(View.VISIBLE); . How should I invalidate the view immediatelly? Neither of the methods I used after icon.setVisibility(View.VISIBLE); did not work.

Answer 1

It won't actually become visible until after it has gone through an onMeasure and an onDraw. Until onMeasure it doesn't know its height, until onDraw it doesn't have a cache. You're going to have to do this after the draw occurs. There's no way to make it happen immediately.