使用UIImage作为掩码来填充不同的颜色

Question

我发现此代码here，但我不确定如何使用它。

- (void)drawRect:(CGRect)rect 
{ 
    CGRect bounds = [self bounds]; 
    [[UIColor blackColor] set]; 
    CGContextRef context = UIGraphicsGetCurrentContext(); 
    CGContextClipToMask(context, bounds, [myImage CGImage]); 
    CGContextFillRect(context, bounds); 
} 

上午我继承一个UIImage？ drawRect在哪里需要被调用？谢谢

Answer 1

希望能帮助你。

#pragma mark - Fill color To Image 
-(void)fillColorToImage:(SelectedObject *)obj Color:(UIColor *)tintColor{ 
UIGraphicsBeginImageContextWithOptions(obj.image.size, NO, 0.0f); 
[tintColor setFill]; 
CGRect bounds = CGRectMake(0, 0, obj.image.size.width, obj.image.size.height); 
UIRectFill(bounds); 
[obj.image drawInRect:bounds blendMode:kCGBlendModeDestinationIn alpha:1.0]; 
imgFillColor = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, obj.frame.size.width, obj.frame.size.height)]; 
imgFillColor.image = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 
[self.view addSubview:imgFillColor]; 
// [self.view addSubview:imgVw]; 
imageview.image = [self maskImage:imageview.image withMask:imgFillColor.image]; 
[self.view addSubview:btnNav]; 
} 
#pragma mark - mask 
- (UIImage*) maskImage:(UIImage *) image withMask:(UIImage *) mask 
{ 
CGImageRef imageReference = image.CGImage; 
CGImageRef maskReference = mask.CGImage; 

CGImageRef imageMask = CGImageMaskCreate(CGImageGetWidth(maskReference), 
             CGImageGetHeight(maskReference), 
             CGImageGetBitsPerComponent(maskReference), 
             CGImageGetBitsPerPixel(maskReference), 
             CGImageGetBytesPerRow(maskReference), 
             CGImageGetDataProvider(maskReference), 
             NULL, // Decode is null 
             YES // Should interpolate 
             ); 

CGImageRef maskedReference = CGImageCreateWithMask(imageReference, imageMask); 
CGImageRelease(imageMask); 

UIImage *maskedImage = [UIImage imageWithCGImage:maskedReference]; 
CGImageRelease(maskedReference); 

return maskedImage; 
}