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iOS

Posted by Paul Denlinger
Paul Denlinger
3,292 Points

Can't create array of UIImage objects

Am trying to create an array for the Code Challenge in Image Based Animation, but am getting an error. The challenge is to: "Assume you have images named 'Robot1.png','Robot2.png','Robot3.png','Robot4.png', create an array of UIImage objects called 'robotImages'" The code I have entered is: UIImage *robotImages = [[NSArray alloc]initWithObjects:@"Robot1", @"Robot2", @"Robot3", @"Robot4", nil];

What am I doing wrong?

1 Answer

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

you need to instantiate an array not a UIImage

NSArray *robotImages = [[NSArray alloc]initWithObjects:@"Robot1", @"Robot2", @"Robot3", @"Robot4", nil];
Paul Denlinger
Paul Denlinger
3,292 Points

OK, I made the change to: NSArray *robotImages = [[NSArray alloc]initWithObjects:@"Robot1", @"Robot2", @"Robot3", @"Robot4", nil];

But I get this message: Bummer! Make sure you create an NSArray named 'robotImages' with instances of UIImage objects.

Stone Preston
Stone Preston
42,016 Points

ok I was assuming you had already initialized the UIImages. If you havent, you can do it inside the array init like so 

NSArray *robotImages = [[NSArray alloc]initWithObjects:[UIImage imageNamed:@"Robot1"], [UIImage imageNamed:@"Robot2"], nil];
Paul Denlinger
Paul Denlinger
3,292 Points

Thank you, that worked.

For the next question: Set the animation images property of 'imageView' to 'robotImages'.

I wrote the following: self.imageView.animationImages = robotImages;

But got the response: Bummer! Make sure you create an NSArray named 'robotImages' with instances of UIImage objects.

Stone Preston
Stone Preston
42,016 Points

did you put that code before or after your array init. it needs to go after. If you passed that last challenge your code should have worked, at least it looked like it should. Unless you cant reference the animationImage property using dot notation but I doubt thats it

Paul Denlinger
Paul Denlinger
3,292 Points

I place the new line of code after the previous line, after that first line tested and passed.

Any other suggestions?

Stone Preston
Stone Preston
42,016 Points

try just imageView.animationImages instead of self.ImageView

Paul Denlinger
Paul Denlinger
3,292 Points

OK, that worked.

Also finished the two remaining tasks.

Thank you.

Stone Preston
Stone Preston
42,016 Points

no problem