对于UIbutton的两个属性imageInset、titleInset一直没有太明白，最近研究了一下，对于不对的地方，欢迎指正啊。
首先要理解，这里的（top、left、bottom、right）并不是直接代表距离button的边界距离，而是现在的一个边界距离相对以前的偏移量，系统默认条件下，图片在左，文字在右。
接着就需要计算出原始image的宽高，title的原始位置，以及现在的位置，下面是简单实现的代码：
-(void)test1//图片在左，文字在右
{
self.button1.contentHorizontalAlignment=UIControlContentHorizontalAlignmentRight;
//self.button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
//以上这两个设置都是可以的
CGFloattitleWidth =60;
CGFloatshowImageWidth =30;
CGFloatoriginalImageWidth =self.button1.frame.size.width>ImageWidth?ImageWidth:self.button1.frame.size.width;
CGFloatleftInset = (self.button1.frame.size.width-titleWidth-showImageWidth)/2;
CGFloatrightInset = leftInset;
CGFloattitleOrigionX = originalImageWidth;
[self.button1setImageEdgeInsets:UIEdgeInsetsMake(0, leftInset,0, rightInset+titleWidth)];
[self.button1setTitleEdgeInsets:UIEdgeInsetsMake(0, leftInset+showImageWidth-titleOrigionX,0, rightInset)];
}
实现效果：
-(void)test2//文字在左，图片在右
{
//self.button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentRight;
self.button1.contentHorizontalAlignment=UIControlContentHorizontalAlignmentLeft;
//以上这两种设置都可以
CGFloattitleWidth =60;
CGFloatshowImageWidth =30;
CGFloatoriginalImageWidth =self.button1.frame.size.width>ImageWidth?ImageWidth:self.button1.frame.size.width;
CGFloatleftInset = (self.button1.frame.size.width-titleWidth-showImageWidth)/2;
CGFloatrightInset = leftInset;
CGFloattitleOrigionX = originalImageWidth;
[self.button1setImageEdgeInsets:UIEdgeInsetsMake(0, leftInset+titleWidth,0, rightInset)];
[self.button1setTitleEdgeInsets:UIEdgeInsetsMake(0, leftInset-titleOrigionX,0, rightInset+showImageWidth)];
}
实现效果：
-(void)test3//图片在上，文字在下
{
//self.button2.contentHorizontalAlignment = UIControlContentHorizontalAlignmentRight;
self.button2.contentHorizontalAlignment=UIControlContentHorizontalAlignmentLeft;
//以上这两个设置都是可以的
CGFloattitleWidth =60;
CGFloattitleHight =20;
CGFloatshowImageWidth =30;
CGFloatshowImageHight = showImageWidth;
CGFloatoriginalImageWidth =self.button2.frame.size.width>ImageWidth?ImageWidth:self.button2.frame.size.width;
CGFloattitleOrigionX = originalImageWidth;
CGFloatimageLeftInset = (self.button2.frame.size.width-showImageWidth)/2;
CGFloatimageRightInset = imageLeftInset;
CGFloattitleLeftInset = (self.button2.frame.size.width-titleWidth)/2;
CGFloattitleRightInset = titleLeftInset;
CGFloattopInset = (self.button2.frame.size.height-showImageHight-titleHight)/2;
CGFloatbottomInset = topInset;
[self.button2setImageEdgeInsets:UIEdgeInsetsMake(topInset,imageLeftInset, titleHight+bottomInset,imageRightInset)];
[self.button2setTitleEdgeInsets:UIEdgeInsetsMake(topInset+showImageHight, titleLeftInset-titleOrigionX, bottomInset, titleRightInset)];
}
实现效果：
