如何使用自动布局避免 UITextField 和键盘之间的冲突？

Question

1.I不喜欢用任何第三方框架做，只有约束有没有可能？

好的，我试过了:)

使用约束 IBOutlet 我需要更新它..

-(void)keyboardDidShow:(NSNotification*)aNotification{
    NSDictionary* info = [aNotification userInfo];

    double animationduration =[info[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    CGRect keyboardEndFrame =[info[UIKeyboardFrameEndUserInfoKey] CGRectValue];

    NSLog(@"this is user info notification keyboard did show==%@",info);
}

指导我的朋友们实现这个:)

Answer 1

按照以下步骤操作：

每当键盘出现时，只需更改 constant 的输出根据您的需要进行约束。
然后通过调用 [self updateConstraintIfNeeded]
然后通过调用 [self layoutIfNeeded]
每当键盘出现故障时，将您的常量改回原来的
再次关注 3 和 4

提示：
在 UIView 动画块中调用布局更新调用将帮助您平滑过渡。

如果你想获得键盘尺寸：

- (void)keyboardWillShow:(NSNotification*)notification {
   NSDictionary *info = [notification userInfo];
   CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
   CGFloat deltaHeight = kbSize.height - _currentKeyboardHeight; 
   // Write code to adjust views accordingly using deltaHeight
   _currentKeyboardHeight = kbSize.height;

}

就这些了。

Answer 2

您必须更改 NSLayoutConstraint 中的 constant 属性。那你得刷新布局了

如果您的 IBOutlet 是：

@property (nonatomic, weak) IBOutlet NSLayoutConstraint *bottomConstraint;

并且NSLayoutConstraint中的初始常数值为bottomInitialValue

代码应该是：

- (void) keyboardDidShow:(NSNotification*) aNotification
{
    NSDictionary* info = [aNotification userInfo];

    double animationduration =[info[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    CGRect keyboardEndFrame =[info[UIKeyboardFrameEndUserInfoKey] CGRectValue];

    bottomConstraint.constant = keyboardEndFrame.size.height + bottomInitialValue;
    [self.view layoutIfNeeded];
}

当键盘消失时，您必须将constant 属性设置为初始值：

bottomConstraint.constant = bottomInitialValue;
[self.view layoutIfNeeded];

Answer 3

获取imageView 顶部约束IBOutlet

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *constraintImageViewTop;

向上

- (void)keyboardWillShow:(NSNotification*)notification
 {
    NSDictionary *info = [notification userInfo];
    CGSize kbHeight = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
    constraintImageViewTop.constant = constraintImageViewTop.constant - kbSize.height;
 }

向下

- (void)keyboardWillHide:(NSNotification *)notification
 {
    NSDictionary *info = [notification userInfo];
    CGSize kbHeight = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size;
    constraintImageViewTop.constant = constraintImageViewTop.constant + kbSize.height;
 }

使 PhoneNumber(textfield) 底部约束优先级低

如何使用自动布局避免 UITextField 和键盘之间的冲突？

How to avoid collision between UITextField and Keyboard using auto layout?

objective-c

uikeyboard

ios

nslayoutconstraint