#if __IPHONE_OS_VERSION_MIN_REQUIRED >= 70000
#define SS_SINGLELINE_TEXTSIZE(text, font) [text length] > 0 ? [text
\ sizeWithAttributes:@{NSFontAttributeName:font}] : CGSizeZero;
#else #define SS_SINGLELINE_TEXTSIZE(text, font) [text length] > 0 ? [text sizeWithFont:font] : CGSizeZero;
#endif
@implementation UIButton (Edge)
- (void)setImagePositionWithType:(SSImagePositionType)type spacing:(CGFloat)spacing {
CGSize imageSize = [self imageForState:UIControlStateNormal].size;
CGSize titleSize = SS_SINGLELINE_TEXTSIZE([self titleForState:UIControlStateNormal], self.titleLabel.font);
switch (type) {
case SSImagePositionTypeLeft: {
self.titleEdgeInsets = UIEdgeInsetsMake(0, spacing, 0, 0);
self.imageEdgeInsets = UIEdgeInsetsMake(0, 0, 0, spacing);
break;
}
case SSImagePositionTypeRight: {
self.titleEdgeInsets = UIEdgeInsetsMake(0, - imageSize.width, 0, imageSize.width + spacing);
self.imageEdgeInsets = UIEdgeInsetsMake(0, titleSize.width + spacing, 0, - titleSize.width);
break;
}
case SSImagePositionTypeTop: {
// lower the text and push it left so it appears centered
// below the image
self.titleEdgeInsets = UIEdgeInsetsMake(0, - imageSize.width, - (imageSize.height + spacing), 0);
// raise the image and push it right so it appears centered
// above the text
self.imageEdgeInsets = UIEdgeInsetsMake(- (titleSize.height + spacing), 0, 0, - titleSize.width);
break;
}
case SSImagePositionTypeBottom: {
self.titleEdgeInsets = UIEdgeInsetsMake(- (imageSize.height + spacing), - imageSize.width, 0, 0);
self.imageEdgeInsets = UIEdgeInsetsMake(0, 0, - (titleSize.height + spacing), - titleSize.width);
break;
}
}
}
在UIButton中有三个对EdgeInsets的设置：ContentEdgeInsets、titleEdgeInsets、imageEdgeInsets
@property(nonatomic) UIEdgeInsets titleEdgeInsets; // default is UIEdgeInsetsZero
@property(nonatomic) UIEdgeInsets imageEdgeInsets; // default is UIEdgeInsetsZero
UIEdgeInsetsMake
里面的四个参数表示距离上边界、左边界、下边界、右边界的距离，默认都为零，title／image在button的正中央
UIKIT_STATIC_INLINE UIEdgeInsets UIEdgeInsetsMake(CGFloat top, CGFloat left, CGFloat bottom, CGFloat right) {
UIEdgeInsets insets = {top, left, bottom, right};
return insets;
}
这里使用button的titleEdgeInsets和imageEdgeInsets属性，通过这两个属性一下子调整过来.先说明，edgeInsets这个属性，就是增加控件的偏移，它是怎么移动空间的呢？4个属性是上，下，左，右。要往右移动5个点，可以这样做，左偏移增加10，或者左增加5并且右减少5，这样也可以。明白了这个原理就好办了，呵呵。
下面来计算偏移量，两个控件，假设图片的尺寸大于文字的尺寸。仅用于计算，实际应用中谁大谁小都无所谓，得到的公式是通用的。
设图片的的宽度为iw,文字的宽度为tw。设button中心点为横轴的零点，那么图片右偏移中心点为delta = (iw+tw)/2-tw=0.5iw-0.5tw。图片需要右移的距离为0.5iw-delta=0.5tw。对应的insets设置为imagedgeinsets=uiinsetsmake(0,0.5tw,0,-0.5tw);文字左偏移的距离为delta+0.5tw=0.5iw-0.5tw+0.5tw=0.5iw，对应的insets设置为titleedgeinsets= uiinsetsmake(0,-0.5iw,0,+0.5iw);
这样设置完成了。
同样的道理，高度也可以设置完成。最终为imageedgeinsets = uiinsetsmake(-0.5th,0.5tw,0.5th,-0.5tw);titeledgeinsets=uiinsetmake(0.5ih,-0.5iw,-0.5ih,+0.5iw）
根据insets特点，可以替换为：image:(-th,tw,0,0);title:(ih,-iw,0,0）从Label到Image这个顺序看，修改的值分别为正，负，负，正)，修改的值是前两项，分别是对方的高，宽，符号为正负负正，这就是正，负，负，正原理。
UIButton*itemButton = [UIButton buttonWithType:UIButtonTypeCustom];
[itemButton setTitleColor:COLOR_WITH_RGBString(@"666666") forState:UIControlStateNormal];
NSString*titleStr =@"title";
[itemButton setTitle:titleStr forState:UIControlStateNormal];
UIImage *btnImage = [UIImage imageNamed:@"image"];
[itemButton setImage:btnImage forState:UIControlStateNormal];
itemButton.frame=CGRectMake(0,0,KSCREENWIDTH,70);
itemButton.titleLabel.font= [UIFont systemFontOfSize:13];
CGSize titleSize = [titleStr boundingRectWithSize:CGSizeMake(KSCREENWIDTH, itemButton.titleLabel.frame.size.height) options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName:[UIFontsystemFontOfSize:13]} context:nil].size;
itemButton.imageEdgeInsets=UIEdgeInsetsMake(-titleSize.height/2+15, titleSize.width/2, titleSize.height/2, -titleSize.width/2);
itemButton.titleEdgeInsets=UIEdgeInsetsMake(btnImage.size.height/2+30, -btnImage.size.width/2, -btnImage.size.height/2, btnImage.size.width/2);
另外一种可行办法 图片在右，文字在左
[button setTitleEdgeInsets:UIEdgeInsetsMake(0, -image.size.width, 0, image.size.width)];
[button setImageEdgeInsets:UIEdgeInsetsMake(0, button.titleLabel.bounds.size.width, 0, -button.titleLabel.bounds.size.width)];