CODEWITHSUNDEEP
iphone
Kyle Decot
Kyle Decot

Reputation: 20835

CALayer w/ Animation as UIViews layer

I have a UIView & I want that view's layer to be a continuously looping animation but I'm having some trouble getting started. I have the following in my view subclass:

+ (Class)layerClass {

return [CALayer class];

}

Then in my viewController I have:

CAGradientLayer *gradient = [CAGradientLayer layer];
[gradient setColors:[NSArray arrayWithObjects:[UIColor redColor],[UIColor blueColor],nil]];
[[[self view] layer] addSublayer:gradient];

This crashes my app. What exactly am I doing wrong? The app crashes w/ EXC_BAD_ACCESS.

Upvotes: 0

Views: 778

Answers (2)

AechoLiu
AechoLiu

Reputation: 18428

You forget to specify the locations for colors. By default, the location is nil.

CAGradientLayer *gradient = [CAGradientLayer layer];
[gradient setColors:[NSArray arrayWithObjects:
          [[UIColor redColor] CGColor],
          [[UIColor blueColor] CGColor],
          nil]];

[gradient setLocations:
          [NSNumber numberWithFloat:0.0],  // for redColor
          [NSNumber numberWithFloat:1.0],  // for blueColor
          nil]];

[[[self view] layer] addSublayer:gradient];

Upvotes: 0

Matt Long
Matt Long

Reputation: 24486

Actually the crash you are having isn't related to not setting locations. The issue has to do with the fact that you're passing the wrong types in your setColors array. A CGColorRef is the types that is expected. Your code should look like this:

CAGradientLayer *gradient = [CAGradientLayer layer];
[gradient setColors:[NSArray arrayWithObjects:(id)[[UIColor redColor] CGColor],
                                        (id)[[UIColor blueColor] CGColor],nil]];
[[[self view] layer] addSublayer:gradient];

The locations parameter of a CAGradientLayer is optional.

Best regards.

Upvotes: 1

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