Implement drag from NSImageView and save image to a file

Question

I've studied Apple's example: CocoaDragAndDrop. I understand how to drag a image to NSImageView and drag an image between views. However, I still don't known how to drag an image and save it to a file when the image is dropped onto the Finder.

Can anybody give me a example?

Answer 1

I finally found out how to do it. And I wrote a demo on Github

Answer 2

-(IBAction)saveImageButtonPushed:(id)sender
{
    NSLog(@"saveImageButtonPushed");

    NSBitmapImageRep *rep;
    NSData *data;
    NSImage *image;

    [self lockFocus];
    rep = [[NSBitmapImageRep alloc] initWithFocusedViewRect:[self frame]];
    [self unlockFocus];

    image = [[[NSImage alloc] initWithSize:[rep size]] autorelease];
    [image addRepresentation:rep];

    data = [rep representationUsingType: NSPNGFileType properties: nil];
        //save as png but failed
    [data writeToFile: @"asd.png" atomically: NO];

        //save as pdf, succeeded but with flaw
    data = [self dataWithPDFInsideRect:[self frame]];
    [data writeToFile:@"asd.pdf" atomically:YES];
}
//......
@end