如何动画更改UITextField的边框颜色？ [英] How do I animate changing the border colour of a UITextField?

问题描述

我从这个以下问题应该为我的UITextField边框的颜色变化设置动画：

I infer from this question that the following should animate the colour change of my UITextField's border:

        [UIView animateWithDuration:5.0f animations:^() {
            myUITextField.layer.borderColor = [UIColor greenColor].CGColor;
        }];

但事实并非如此，边框会立即改变颜色。很明显我做错了什么？

But it doesn't, the border changes colour instantly. Is it obvious what I'm doing wrong?

更新：好的，所以尝试以下隐式动画：

Update: Ok, so trying the following implicit animation:

        [CATransaction begin];
        [CATransaction setValue:[NSNumber numberWithFloat:5.0f] forKey:kCATransactionAnimationDuration];
            myUITextField.layer.borderColor = [UIColor greenColor].CGColor;
        [CATransaction commit];

这也没有动画，效果相同：它立即改变颜色（顺便说一下，哪里有对于layer.borderColor记录的kCATransactionAnimationDuration的默认值是什么？）

And that doesn't animate either, same effect: it changes colour instantly (as an aside, where's the default for kCATransactionAnimationDuration for layer.borderColor documented?)

推荐答案

我相信 CALayer c> UIView 动画块中的$ c>属性不可动画。您需要设置 CABasicAnimation 并将该动画添加到图层中。

I believe that CALayer properties are not animatable in a UIView animation block. You would need to set up a CABasicAnimation and add that animation to the layer instead.

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