I noticed that when I place a white or black UIImage
into a UISegmentedControl
it automatically color masks it to match the tint of the segmented control. I thought this was really cool, and was wondering if I could do this elsewhere as well. For example, I have a bunch of buttons that have a uniform shape but varied colors. Instead of making a PNG for each button, could I somehow use this color masking to use the same image for all of them but then set a tint color or something to change their actual color?
17 Answers
As of iOS 7, there is a new method on UIImage
to specify the rendering mode. Using the rendering mode UIImageRenderingModeAlwaysTemplate
will allow the image color to be controlled by the button's tint color.
Objective-C
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [[UIImage imageNamed:@"image_name"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[button setImage:image forState:UIControlStateNormal];
button.tintColor = [UIColor redColor];
Swift
let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red
As Ric already mentioned in his post you can set the render mode in code, you can also do this directly in the image catalog, see attached image below. Just set the Render As
to Template Image
Caveat I have had problems with iOS 7 and this approach. So if you use iOS 7 as well you might want to do it in code as well to be sure, as described here.
You must set the image rendering mode to UIImageRenderingModeAlwaysTemplate
in order to have the tintColor
affect the UIImage. Here is the solution in Swift:
let image = UIImage(named: "image-name")
let button = UIButton()
button.setImage(image?.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate), forState: .Normal)
button.tintColor = UIColor.whiteColor()
SWIFT 4x
button.setImage(image.withRenderingMode(UIImage.RenderingMode.alwaysTemplate), for: .normal)
button.tintColor = UIColor.blue
If you have a custom button with a background image.You can set the tint color of your button and override the image with following .
In assets select the button background you want to set tint color.
In the attribute inspector of the image set the value render as to "Template Image"
Now whenever you setbutton.tintColor = UIColor.red
you button will be shown in red.
In Swift you can do that like so:
var exampleImage = UIImage(named: "ExampleImage.png")?.imageWithRenderingMode(.AlwaysTemplate)
Then in your viewDidLoad
exampleButtonOutlet.setImage(exampleImage, forState: UIControlState.Normal)
And to modify the color
exampleButtonOutlet.tintColor = UIColor(red: 1, green: 0, blue: 0, alpha: 1) //your color
EDIT Xcode 8
Now you can also just the rendering mode of the image in your .xcassets to Template Image and then you don't need to specifically declare it in the var exampleImage
anymore
Not sure exactly what you want but this category method will mask a UIImage with a specified color so you can have a single image and change its color to whatever you want.
ImageUtils.h
- (UIImage *) maskWithColor:(UIColor *)color;
ImageUtils.m
-(UIImage *) maskWithColor:(UIColor *)color
{
CGImageRef maskImage = self.CGImage;
CGFloat width = self.size.width;
CGFloat height = self.size.height;
CGRect bounds = CGRectMake(0,0,width,height);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext = CGBitmapContextCreate(NULL, width, height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
CGContextClipToMask(bitmapContext, bounds, maskImage);
CGContextSetFillColorWithColor(bitmapContext, color.CGColor);
CGContextFillRect(bitmapContext, bounds);
CGImageRef cImage = CGBitmapContextCreateImage(bitmapContext);
UIImage *coloredImage = [UIImage imageWithCGImage:cImage];
CGContextRelease(bitmapContext);
CGColorSpaceRelease(colorSpace);
CGImageRelease(cImage);
return coloredImage;
}
Import the ImageUtils category and do something like this...
#import "ImageUtils.h"
...
UIImage *icon = [UIImage imageNamed:ICON_IMAGE];
UIImage *redIcon = [icon maskWithColor:UIColor.redColor];
UIImage *blueIcon = [icon maskWithColor:UIColor.blueColor];
Swift 3:
This solution could be comfortable if you have already setted your image through xCode interface builder. Basically you have one extension to colorize an image:
extension UIImage {
public func image(withTintColor color: UIColor) -> UIImage{
UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
let context: CGContext = UIGraphicsGetCurrentContext()!
context.translateBy(x: 0, y: self.size.height)
context.scaleBy(x: 1.0, y: -1.0)
context.setBlendMode(CGBlendMode.normal)
let rect: CGRect = CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height)
context.clip(to: rect, mask: self.cgImage!)
color.setFill()
context.fill(rect)
let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}
}
Then , you can prepare this UIButton extension to colorize the image for a particular state:
extension UIButton {
func imageWith(color:UIColor, for: UIControlState) {
if let imageForState = self.image(for: state) {
self.image(for: .normal)?.withRenderingMode(.alwaysTemplate)
let colorizedImage = imageForState.image(withTintColor: color)
self.setImage(colorizedImage, for: state)
}
}
}
Usage:
myButton.imageWith(.red, for: .normal)
P.S. (working good also in table cells, you don't need to call setNeedDisplay()
method, the change of the color is immediate due to the UIImage extension..
For Xamarin.iOS (C#):
UIButton messagesButton = new UIButton(UIButtonType.Custom);
UIImage icon = UIImage.FromBundle("Images/icon.png");
messagesButton.SetImage(icon.ImageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate), UIControlState.Normal);
messagesButton.TintColor = UIColor.White;
messagesButton.Frame = new RectangleF(0, 0, 25, 25);
If you want to manually mask your image, here is updated code that works with retina screens
- (UIImage *)maskWithColor:(UIColor *)color
{
CGImageRef maskImage = self.CGImage;
CGFloat width = self.size.width * self.scale;
CGFloat height = self.size.height * self.scale;
CGRect bounds = CGRectMake(0,0,width,height);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext = CGBitmapContextCreate(NULL, width, height, 8, 0, colorSpace, kCGBitmapAlphaInfoMask & kCGImageAlphaPremultipliedLast);
CGContextClipToMask(bitmapContext, bounds, maskImage);
CGContextSetFillColorWithColor(bitmapContext, color.CGColor);
CGContextFillRect(bitmapContext, bounds);
CGImageRef cImage = CGBitmapContextCreateImage(bitmapContext);
UIImage *coloredImage = [UIImage imageWithCGImage:cImage scale:self.scale orientation:self.imageOrientation];
CGContextRelease(bitmapContext);
CGColorSpaceRelease(colorSpace);
CGImageRelease(cImage);
return coloredImage;
}
You Should Try
After Setting The Frame
NSArray *arr10 =[NSArray arrayWithObjects:btn1,btn2,nil];
for(UIButton *btn10 in arr10)
{
CAGradientLayer *btnGradient2 = [CAGradientLayer layer];
btnGradient2.frame = btn10.bounds;
btnGradient2.colors = [NSArray arrayWithObjects:
(id)[[UIColor colorWithRed:151.0/255.0f green:206.0/255.5 blue:99.0/255.0 alpha:1] CGColor],
(id)[[UIColor colorWithRed:126.0/255.0f green:192.0/255.5 blue:65.0/255.0 alpha:1]CGColor],
nil];
[btn10.layer insertSublayer:btnGradient2 atIndex:0];
}
Swift 3.0
let image = UIImage(named:"NoConnection")!
warningButton = UIButton(type: .system)
warningButton.setImage(image, for: .normal)
warningButton.tintColor = UIColor.lightText
warningButton.frame = CGRect(origin: CGPoint(x:-100,y:0), size: CGSize(width: 59, height: 56))
self.addSubview(warningButton)
let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red
If you are setting UIButton.tintColor
by UIColor(r:g:b:alpha:)
, remember to divide values by 255
. Those RGB values should be in between 0 and 1.