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?


当前回答

如果你想手动屏蔽你的图像,这里是更新的代码,适用于视网膜屏幕

- (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;
}

其他回答

正如Ric已经在他的帖子中提到的,你可以在代码中设置渲染模式,你也可以直接在图像目录中这样做,见下面所附的图像。只需要设置渲染为模板图像

注意,我在使用iOS 7和这种方法时遇到过问题。如果你也使用iOS 7,你可能也想在代码中完成,就像这里描述的。

你应该试试

设置好框架后

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];

}

斯威夫特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)

不确定你到底想要什么,但这个category方法会用指定的颜色掩盖一个UIImage,所以你可以有一个单独的图像,改变它的颜色为任何你想要的。

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;    
}

导入ImageUtils类别并执行如下操作…

#import "ImageUtils.h"

...

UIImage *icon = [UIImage imageNamed:ICON_IMAGE];

UIImage *redIcon = [icon maskWithColor:UIColor.redColor];
UIImage *blueIcon = [icon maskWithColor:UIColor.blueColor];

从ios7开始,在UIImage上有一个新的方法来指定渲染模式。使用渲染模式UIImageRenderingModeAlwaysTemplate将允许图像颜色由按钮的色调颜色控制。

objective - c

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIImage *image = [[UIImage imageNamed:@"image_name"] imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
[button setImage:image forState:UIControlStateNormal]; 
button.tintColor = [UIColor redColor];

斯威夫特

let button = UIButton(type: .custom)
let image = UIImage(named: "image_name")?.withRenderingMode(.alwaysTemplate)
button.setImage(image, for: .normal)
button.tintColor = UIColor.red