Android setVisibility(View.GONE)无效的问题及原因分析
解决方案:可以在setVisibility()之前调用clearAnimation()方法清除掉动画,或setFillAfter(false)(时间上该函数内部也调用了clearAnimation())。
出现这种情况很可能是因为设置了animation,并且调用了setFillAfter(true),这就会导致setVisibility无效,只需要调用一下clearAnimation()方法或者去掉setFillAfter(true)语句即可。
实验证明只要在setVisibility之前设置View的mCurrentAnimation为null就可以,因此调用setAnimation(null)也是可以的。从源码来看setFillAfter为false时也会间接导致调用clearAnimation,而clearAnimation在这里使setVisibility有效的原因也是置mCurrentAnimation为null了。
setFillAfter为false时间接导致clearAnimation:
而mCurrentAnimation使GONE无效的初步分析很可能是下面的代码造成:
在dispatchDraw子View的时候,尽管不为VISIBLE,由于是||的关系,也会导致drawChild被调用。而drawChild的代码如下:
/** * Draw one child of this View Group. This method is responsible for getting * the canvas in the right state. This includes clipping, translating so * that the child's scrolled origin is at 0, 0, and applying any animation * transformations. * * @param canvas The canvas on which to draw the child * @param child Who to draw * @param drawingTime The time at which draw is occurring * @return True if an invalidate() was issued */ protected boolean drawChild(Canvas canvas, View child, long drawingTime) { return child.draw(canvas, this, drawingTime); }