加载gif图片

NSImage *img = [NSImage imageNamed:@"earth.gif"]; // or similar//    [self.window.contentView setWantsLayer:YES];    _imageView.imageScaling = NSImageScaleNone;    _imageView.animates = YES;    _imageView.image = img;    _imageView.canDrawSubviewsIntoLayer = YES;    [_imageView setImage:img];