动画时 UITextField 无法成为第一响应者

Question

At the moment, I am creating a feature that animates a UITextfield from the bottom of the screen to a given point using a UIView animation block.

For some reason while the UITextfield animates upwards, it is unresponsive to touch events and will not become the first responder until after it calls completion.

I have created a sample project below to show the issue.

https://github.com/AdamBCo/Textfield-Animation-Issue

As you can see in the example, UIViewAnimationOptionAllowUserInteraction is set in the UViewAnimation block.

Any help on this issue would be greatly appreciated!

Answer 1

I was able to solve the problem by implementing the following solution:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint touchLocation = [touch locationInView:self.view];

    if ([self.textField.layer.presentationLayer hitTest:touchLocation])
    {
        [self.textField becomeFirstResponder];
    }
}

I have since updated the sample code online to show the animation of the presentation layer, the ending destination of the model layer, and a way to see if the clicks are inside of the presentation layer.

Answer 2

This is actually the intended action. What you are seeing is the CALayer animating therefore it won't respond to a touch until it's "landed". What you can do is add a touch recognizer then test your hit points to begin responding on a certain object. I have to ask though, what UI/UX scenario would this be good practice?