从1024 * 1024大小NSImage以编程方式创建图标

Question

我试图通过编程方式从1024x1024图像创建大小为120 * 120的ICNS。目前我正在创建一个NSImage，然后创建具有适当分辨率的CGImageRef对象，最后使用CGImageDestinationAddImage()将它们保存到路径中。

我已经浏览过各种链接，其中之一是：Creating an ICNS programmatically: "Unsupported Image Size"

但问题是，代码生成了相同大小的图标文件。(1024 * 1024)

下面是代码：

- (void)generateIconSizeFromImage:(NSString *)path
{
    //destination path

    NSURL *fileURL = [NSURL fileURLWithPath:@"/Users/harjotsingh/Desktop/TestIconGenerated/test1@2x.png"];
    CGImageDestinationRef dr = CGImageDestinationCreateWithURL((__bridge CFURLRef)fileURL, kUTTypePNG , 1, NULL);

    //image from path
    NSImage *img = [[NSImage alloc] initWithContentsOfFile:path];

    //setting its size to one of icon size
    [img setSize:NSMakeSize(60,60)];

    //setting its rep size to one of icon size
    for (NSImageRep *rep in [img representations])[rep setSize:NSMakeSize(60,60)];

    //setting the dpi, so it create 120 * 120 size icon file
    NSDictionary *imageProps1x = @{
                                   (__bridge NSString *)kCGImagePropertyDPIWidth: @144.0,
                                   (__bridge NSString *)kCGImagePropertyDPIHeight: @144.0,
                                   };

    // Add rect size
    NSRect prect = NSMakeRect(0,0,60,60);

    //get image for desired size
    CGImageRef generatedImage = [img CGImageForProposedRect:&prect context:[NSGraphicsContext currentContext] hints:nil];

    //sadly it shows the same 1024 * 1024 size
    NSLog(@"width:-- %zu && height:-- %zu",CGImageGetWidth(generatedImage),CGImageGetHeight(generatedImage));

    //adding to destination folder
    CGImageDestinationAddImage(dr, generatedImage, (__bridge CFDictionaryRef)(imageProps1x));

    //finalize.
    CGImageDestinationFinalize(dr);

    CFRelease(dr);
}

从输入路径使用的图像为1024 * 1024像素。1024×1024像素元素的正确规格是512点@ 2x。这是(NSSize){ 512.0,512.0 }(点)的大小(图像和rep)，rep为1024 pixelsWide和1024 pixelsHigh。注:这已得到处理，但仍未取得成功。

Answer 1

我已经经历过这件事，而且几乎没有什么变化就完成了。下面是生成大尺寸图像的图标的工作代码：

- (void)generateIconSizeFromImage:(NSString *)path

{

NSImage * smallImage = [[NSImage alloc] initWithContentsOfFile:path];
[smallImage setSize:NSMakeSize(120,120)];

[smallImage lockFocus];

[[NSGraphicsContext currentContext] setImageInterpolation:NSImageInterpolationHigh];

[smallImage drawInRect:CGRectMake(0, 0, 120,120)];

[smallImage unlockFocus];


//destination path
NSURL *fileURL = [NSURL fileURLWithPath:@"/Volumes/Harjot/Documents/MyProjects/Cobby Mac App/test60@2x.png"];

CGImageDestinationRef dr = CGImageDestinationCreateWithURL((__bridge CFURLRef)fileURL, kUTTypePNG , 1, NULL);

//setting the dpi, so it create 120 * 120 size icon file
NSDictionary *imageProps1x = @{
                               (__bridge NSString *)kCGImagePropertyDPIWidth: @144.0,
                               (__bridge NSString *)kCGImagePropertyDPIHeight: @144.0,
                               };

//get image for desired size
CGImageRef generatedImage = [smallImage CGImageForProposedRect:NULL context:[NSGraphicsContext currentContext] hints:nil];

//now it works and generate the 120 by 120 icon
NSLog(@"width:-- %zu && height:-- %zu",CGImageGetWidth(generatedImage),CGImageGetHeight(generatedImage));

//adding to destination folder
CGImageDestinationAddImage(dr, generatedImage, (__bridge CFDictionaryRef)(imageProps1x));

//finalize.
CGImageDestinationFinalize(dr);

CFRelease(dr);

}

享受:)

Answer 2

绘制rect方法将适用于此。下面是示例代码：

[smallImage drawInRect:CGRectMake(0, 0, 120,120)]


//destination path
NSURL *fileURL = [NSURL fileURLWithPath:@“Your saving path…];

CGImageDestinationRef dr = CGImageDestinationCreateWithURL((__bridge CFURLRef)fileURL, kUTTypePNG , 1, NULL);

//setting the dpi, so it create 120 * 120 size icon file
NSDictionary *imageProps1x = @{
                               (__bridge NSString *)kCGImagePropertyDPIWidth: @144.0,
                               (__bridge NSString *)kCGImagePropertyDPIHeight: @144.0,
                               };

//get image for desired size
CGImageRef generatedImage = [smallImage CGImageForProposedRect:NULL context:[NSGraphicsContext currentContext] hints:nil];

//now it works and generate the 120 by 120 icon
NSLog(@"width:-- %zu && height:-- %zu",CGImageGetWidth(generatedImage),CGImageGetHeight(generatedImage));

//adding to destination folder
CGImageDestinationAddImage(dr, generatedImage, (__bridge CFDictionaryRef)(imageProps1x));