Question

我在scrollView中有几个UITextField，我通过设置

自定义textFields的边框

layer.borderColor = ...,
layer.borderRadius = 3.0,
layer.borderWidth = 0.1,
layer.masksToBounds = YES. 

- (void)keyboardWillShow:(NSNotification *)notification {
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];

CGRect rect = [self.currentTextField superview].frame;

[UIView animateWithDuration:animDuration animations:^{
    [self.scrollView scrollRectToVisible:rect animated:NO];
}];
}

- (void)keyboardWillHide:(NSNotification *)notification {
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGRect rect = [self.currentTextField superview].frame;
[UIView animateWithDuration:animDuration animations:^{        
    [self.scrollView scrollRectToVisible:rect animated:NO];
}];
}

每次我有任何textField聚焦或关闭键盘时，所有文本字段的边框都会闪烁。但是，如果我只是滚动滚动浏览没有闪烁

Answer 1

我终于找到了解决方案。使用CoreAnimation rasteraztion，将textField的图层的shouldRasterize切换为true：textField.layer.shouldRasterize = true 并设置比例：textField.layer.rasterizationScale = UIScreen.mainScreen（）。scale shouldRasterize指示CoreAnimatin将图层内容缓存为图像。然后你摆脱了闪烁。为避免任何不必要的缓存，您应该在动画完成后立即关闭光栅化。

整个代码如下：

<pojosEqualsAndHashCode>true</pojosEqualsAndHashCode>

}

- (void)keyboardWillShow:(NSNotification *)notification {
CGRect keyboardRectEnd = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];

CGRect rect = [self.currentTextField superview].frame;
self.scrollViewBottomConstraint.constant = keyboardRectEnd.size.height;

[self toggleTextFieldRasterization:YES];
[UIView animateWithDuration:animDuration animations:^{
    [self.scrollView scrollRectToVisible:rect animated:NO];
    [self layoutIfNeeded];
} completion: ^(BOOL finished) {
    [self toggleTextFieldRasterization:NO];
}];

}

- (void)keyboardWillHide:(NSNotification *)notification {
CGFloat animDuration = [notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] floatValue];
CGRect rect = [self.currentTextField superview].frame;
self.scrollViewBottomConstraint.constant = 0.0;

[self toggleTextFieldRasterization:YES];
[UIView animateWithDuration:animDuration animations:^{
    [self.scrollView scrollRectToVisible:rect animated:NO];
    [self layoutIfNeeded];
} completion:^(BOOL finished) {
    [self toggleTextFieldRasterization:NO];
}];

}

UITextField的边框闪烁

1 个答案: