IOS-button属性edge
IOS中UIButton 的内容，标题，背景在button容器的相对位子的设置
UIButton *button = [UIButton
buttonWithType:UIButtonTypeCustom];//button的类型
button.frame = CGRectMake(100, 100,90, 90);//button的frame
button.backgroundColor = [UIColor cyanColor];//button的背景颜色
// [button setBackgroundImage:[UIImage
imageNamed:@"man_64.png"] forState:UIControlStateNormal];
//
在UIButton中有三个对EdgeInsets的设置：ContentEdgeInsets、titleEdgeInsets、imageEdgeInsets
[button setImage:[UIImage imageNamed:@"IconHome@2x.png"]
forState:UIControlStateNormal];//给button添加image
button.imageEdgeInsets =
UIEdgeInsetsMake(5,13,21,button.titleLabel.bounds.size.width);//设置image在button上的位置（上top，左left，下bottom，右right）这里可以写负值，对上写－5，那么image就象上移动5个像素
[button setTitle:@"首页"
forState:UIControlStateNormal];//设置button的title
button.titleLabel.font = [UIFont
systemFontOfSize:16];//title字体大小
button.titleLabel.textAlignment =
NSTextAlignmentCenter;//设置title的字体居中
[button
setTitleColor:[UIColor whiteColor]
forState:UIControlStateNormal];//设置title在一般情况下为白色字体
[button setTitleColor:[UIColor grayColor]
forState:UIControlStateHighlighted];//设置title在button被选中情况下为灰色字体
button.titleEdgeInsets = UIEdgeInsetsMake(71,
-button.titleLabel.bounds.size.width-50, 0,
0);//设置title在button上的位置（上top，左left，下bottom，右right）
// [button setContentEdgeInsets:UIEdgeInsetsMake(70, 0, 0,
0)];//
// button.contentHorizontalAlignment =
UIControlContentHorizontalAlignmentCenter;//设置button的内容横向居中。。设置content是title和image一起变化
[button addTarget:self action:@selector(tap)
forControlEvents:UIControlEventTouchUpInside];
[self.view
addSubview:button];