UIbutton的三个不同内边距含义

UIbutton *shareButton=[UIbutton alloc] init];
    // 被切掉的区域就不能显示内容了
    // contentEdgeInsets : 切掉按钮内部的内容
   shareButton.contentEdgeInsets = UIEdgeInsetsMake(10, 20, 10, 20);
    // imageEdgeInsets : 切掉按钮内部UIImageView的内容
   shareButton.imageEdgeInsets = UIEdgeInsetsMake(5, 5, 5, 5);

    // titleEdgeInsets : 切掉按钮内部UILabel的内容

shareButton.titleEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 0);