Question

If I instantiate a UIImage like this :

UIImage *image = [[UIImage alloc] init];

The object is created but it doesn’t contain any image.

How I can check if my object contains an image or not?

Answer 1

You can check if it has any image data.

UIImage* image = [[UIImage alloc] init];

CGImageRef cgref = [image CGImage];
CIImage *cim = [image CIImage];

if (cim == nil && cgref == NULL)
{
    NSLog(@"no underlying data");
}
[image release];

Swift Version

let image = UIImage()

let cgref = image.cgImage
let cim = image.ciImage

if cim == nil && cgref == nil {
    print("no underlying data")
}