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  • Android setVisibility(View.GONE)无效的问题及原因分析

    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);
        }
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  • 原文地址:https://www.cnblogs.com/zhujiabin/p/9013748.html
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