更改图像的颜色
//Swift
imageView.tintColor = UIColor.redColor()
imageView.image = imageView.image?.imageWithRenderingMode(.AlwaysTemplate)
//Swift 3
imageView.tintColor = UIColor.red
imageView.image = imageView.image?.withRenderingMode(.alwaysTemplate)
//Objective-C
imageView.tintColor = [UIColor redColor];
imageView.image = [imageView.image imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]