高亮显示如何从UIButton中删除CAGradientLayer

Question

I've added gradient effect for my Button and added it as a sub layer to my Button .

Code is :

CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = self.myButton.layer.bounds;
gradientLayer.colors = [NSArray arrayWithObjects:  (id)[[UIColor whiteColor] colorWithAlphaComponent:0.5].CGColor,(id) colorTwo.CGColor,(id) colorThree.CGColor,(id) colorFour.CGColor, nil];
gradientLayer.locations = [NSArray arrayWithObjects: [NSNumber numberWithFloat:0.0f], [NSNumber numberWithFloat:1.0f], nil];
self.myButton.layer.cornerRadius = 5;
gradientLayer.cornerRadius = self.myButton.layer.cornerRadius;
[self.myButton.layer addSublayer:gradientLayer];

Now when my button is highlighted (touchedDown method called), I want to set new gradient to myButton. Hence I need to remove the old gradient effect when myButton is clicked and add new gradient.

How to remove the old gradient effect ?

I tried

for (CALayer *layer in [self.loginScreenView.btnPowerBroking.layer.sublayers copy]){
        if ([[layer name] isEqualToString:@"gradientLayer"]) {
            NSLog(@"Gradient layer found.");
        }
    }

But I can't get it's gradient layer.

Thanks for your time. (:

Answer 1

You haven't set the name property to your gradientLayer object just set it and it will work.

 gradientLayer.name = @"gradientLayer";
 [self.myButton.layer addSublayer:gradientLayer];

In for loop's if statement remove the layer using this [layer removeFromSuperlayer];

Note : You are adding layer in myButton object in searching inside the btnPowerBroking check properly for that also, you need to search in button where you have added Layer .

Answer 2

试试这个方法...

[self.myButton.layer replaceSublayer:oldgradientLayer with:newgradientLayer];