iPhone UIView以编程方式替换图像颜色,如在Photoshop或Illustrator中

Question

我有一组图形,我想在我的应用程序中重用.它们是具有透明度的按钮和图像.我不想拥有数十个硬编码的按钮图像,而是希望拥有一个按钮图像,并能够动态地为其指定颜色,例如导航栏和它的色彩.

是否有可能替换/改变UIView的色调？

或者:我知道如果我将透明图像覆盖在另一个UIView上,那么我可以改变背景颜色,两个图像将混合在一起.但透明区域将呈现背景的色调.

有没有办法保持透明区域透明,同时将两个图像混合在一起？我听说有剪贴膜,但从未使用它们.

谢谢!

更新:

这应该工作,但返回零图像,我看到其他人报告相同的问题.也许这将在未来发挥作用

-(void)doHueAdjustFilter
{

    //does not work, returns nil image
    CIImage* inputImage = [CIImage imageWithCGImage:[[UIImage imageNamed:@"button.jpg"]CGImage]];

    CIFilter *myFilter;
    NSDictionary *myFilterAttributes;
    myFilter = [CIFilter filterWithName:@"CIHueAdjust"];
    [myFilter setDefaults];

    myFilterAttributes = [myFilter attributes];
    [myFilterAttributes setValue:inputImage forKey:@"inputImage"];
    [myFilterAttributes setValue:[NSNumber numberWithFloat:0.9] forKey:@"inputAngle"];


    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *ciimage = [myFilter outputImage];
    CGImageRef cgimg = [context createCGImage:ciimage fromRect:[ciimage extent]];
    UIImage *uimage = [UIImage imageWithCGImage:cgimg scale:1.0f orientation:UIImageOrientationUp];
    [caduceusImageView setImage:uimage];
    CGImageRelease(cgimg);

}

Answer 1

我对这段代码片段感到非常兴奋.它完全改变了图形或按钮的色调.矢量图形看起来像我在插画中改变了色调.这节省了大量时间,因为我不再需要放弃我的工作,切换到插图画家并开始绘制具有不同色调的按钮.一个按钮适用于所有人!

适用于iOS5

-(UIImage*)doHueAdjustFilterWithBaseImageName:(NSString*)baseImageName hueAdjust:(CGFloat)hueAdjust
{

    CIImage *inputImage = [[CIImage alloc] initWithImage:[UIImage imageNamed:baseImageName]];
    CIFilter * controlsFilter = [CIFilter filterWithName:@"CIHueAdjust"];
    [controlsFilter setValue:inputImage forKey:kCIInputImageKey];

    [controlsFilter setValue:[NSNumber numberWithFloat:hueAdjust] forKey:@"inputAngle"];

    NSLog(@"%@",controlsFilter.attributes);
    CIImage *displayImage = controlsFilter.outputImage;
    UIImage *finalImage = [UIImage imageWithCIImage:displayImage];

    CIContext *context = [CIContext contextWithOptions:nil];
    if (displayImage == nil || finalImage == nil) {
        // We did not get output image. Let's display the original image itself.
       return  [UIImage imageNamed:baseImageName];
    }else {
        // We got output image. Display it.
        return  [UIImage imageWithCGImage:[context createCGImage:displayImage fromRect:displayImage.extent]];
    }


}