Setting the cause and effect of masks to Yes when working on a layer

I've never been able to figure out why to set button.layer.masksToBounds = YES Now that I've been setting the border and rounded corners for the view Image view Button.

When you get to know masks, you'll understand why this is going to work. "A layer can have a

The associated mask mask is a bitmap that has an alpha value when the pixel is merged with the pixels it contains

The mask is applied to the pixels of the layer. When you want to set the fillet radius of a layer, you can effectively

Set a mask above the layer. However, you can also specify any mask. For example, a shape of a letter A

Mask It will only show up in mask (that is, the part of the layer).

For more specific drawing and compositing of pixels, see:

http://blog.csdn.net/u010670117/article/details/44082391

Setting the cause and effect of masks to Yes when working on a layer