Objective c Mac开发人员-映像I/O

我的第一个问题

我正在尝试创建一个简单的应用程序，它从一个位置拍摄一张照片，并将其放在桌面上。我遇到的问题是以下错误：

2012-10-27 10:49:16.405 saveFile[3271:303] +[__NSCFConstantString scheme]: unrecognized selector sent to class 0x7fff73c01e38
    2012-10-27 10:49:16.406 saveFile[3271:303] +[__NSCFConstantString scheme]: unrecognized selector sent to class 0x7fff73c01e38

在这一行：

CGImageRef imageItself =  CGImageSourceCreateImageAtIndex(myImageSource, 0, NULL);

下面是实际代码：

头文件：

#import <Cocoa/Cocoa.h>

//NSOpenPanel = use finder
NSOpenPanel *openPanel;
//URL is the directory
NSURL*  theDoc;


//Don't allow bottom button to malfunction by being clicked early.
bool topButtonClicked = NO;

@interface saveFileAppDelegate : NSObject <NSApplicationDelegate>

- (IBAction)moveFile:(id)sender;
- (IBAction)chooseFile:(id)sender;



@property (nonatomic, retain) IBOutlet NSTextField *label;
@property (assign) IBOutlet NSWindow *window;

@end

在这里

我设法把它修好了。我把它抽象了一点，并且尽可能地延长了每个方法，这样我就可以一步一步地看到它。我想我会为任何一个偶然发现我的问题的人发布我的修正

以下是.m中移动文件部分的结束代码：

- (IBAction)moveFile:(id)sender {

    if (topButtonClicked == YES) {

        //Take in picture

        CFURLRef CFURLReftheDoc = (__bridge CFURLRef)theDoc;

        CGImageSourceRef myImageSource = CGImageSourceCreateWithURL(CFURLReftheDoc, NULL);

        //Create a reference to the image itself, take in the image read, which image (only one, so 0), and additional options.
        CGImageRef imageItself =  CGImageSourceCreateImageAtIndex(myImageSource, 0, NULL);

        //Save picture to desktop

        //Store desktop directory.
        NSString *path = [@"~/Desktop/public.png" stringByExpandingTildeInPath];

        NSURL *NSURLdesktopURL = [[NSURL alloc] initFileURLWithPath:path];

        NSLog(@"%@",NSURLdesktopURL);

        //store where I want to save, the type of file I expect to save, number of images to save, any additional options.
        CGImageDestinationRef whereToSave = CGImageDestinationCreateWithURL((__bridge CFURLRef)NSURLdesktopURL, kUTTypeJPEG, 1, NULL);

               // NSLog(@"%@",whereToSave);

        //Begin final preperations, pull altogether desktop URL, the image read in before, and additional options.
        CGImageDestinationAddImage (whereToSave, imageItself, NULL);

        //Finalize (write the file)
        CGImageDestinationFinalize(whereToSave);

        //CGImageDestinationRef saveImageToDesktop (CFURLRef desktop, CFStringRef jpeg, size_t count, CFDictionaryRef NULL);

    }
    else{


        /* open an alert with an OK button */
        NSAlert *alert = [[NSAlert alloc] init];
        [alert setMessageText:@"Stop it."];
        [alert runModal];
    }
}
@end

- (IBAction)moveFile:(id)sender {

    if (topButtonClicked == YES) {

        //Take in picture

        CFURLRef CFURLReftheDoc = (__bridge CFURLRef)theDoc;

        CGImageSourceRef myImageSource = CGImageSourceCreateWithURL(CFURLReftheDoc, NULL);

        //Create a reference to the image itself, take in the image read, which image (only one, so 0), and additional options.
        CGImageRef imageItself =  CGImageSourceCreateImageAtIndex(myImageSource, 0, NULL);

        //Save picture to desktop

        //Store desktop directory.
        NSString *path = [@"~/Desktop/public.png" stringByExpandingTildeInPath];

        NSURL *NSURLdesktopURL = [[NSURL alloc] initFileURLWithPath:path];

        NSLog(@"%@",NSURLdesktopURL);

        //store where I want to save, the type of file I expect to save, number of images to save, any additional options.
        CGImageDestinationRef whereToSave = CGImageDestinationCreateWithURL((__bridge CFURLRef)NSURLdesktopURL, kUTTypeJPEG, 1, NULL);

               // NSLog(@"%@",whereToSave);

        //Begin final preperations, pull altogether desktop URL, the image read in before, and additional options.
        CGImageDestinationAddImage (whereToSave, imageItself, NULL);

        //Finalize (write the file)
        CGImageDestinationFinalize(whereToSave);

        //CGImageDestinationRef saveImageToDesktop (CFURLRef desktop, CFStringRef jpeg, size_t count, CFDictionaryRef NULL);

    }
    else{


        /* open an alert with an OK button */
        NSAlert *alert = [[NSAlert alloc] init];
        [alert setMessageText:@"Stop it."];
        [alert runModal];
    }
}
@end