效果

首先需要知道纯颜色生成UIImage的方法

func imageWithColor(color:UIColor,size:CGSize) ->UIImage{

    let rect =CGRect(x:0, y:0, width: size.width, height: size.height)

    UIGraphicsBeginImageContext(rect.size)

    let context =UIGraphicsGetCurrentContext()

    CGContextSetFillColorWithColor(context, color.CGColor)

    CGContextFillRect(context, rect)

    let image =UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext()

    return image

}

然后设置UIButton 就OK了

let button =UIButton(frame:CGRect(x:100, y:100, width:100, height:100))

button.setBackgroundImage(imageWithColor(UIColor.whiteColor(), size: button.frame.size), forState: .Highlighted)

button.setBackgroundImage(imageWithColor(UIColor.redColor(), size: button.frame.size), forState: .Normal)

button.setTitle("哈哈", forState: .Normal)

button.titleLabel?.font=UIFont.systemFontOfSize(15)

button.setTitleColor(UIColor.redColor(), forState: .Highlighted)

button.setTitleColor(UIColor.whiteColor(), forState: .Normal)

view.addSubview(button)

就是如此简单！