前言
很久没写技术文章里,本篇记录了一下一个键盘弹出的小细节动画,像微信一样流程
上图
动画细节代码
细节核心主要是通知中的一些key
- 动画时长
- 动画的出现方式
…
下面的通知是接收 键盘将要出现的通知UIKeyboardWillShowNotification
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[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(didReceiveKeyboardShowNotification:)
name:UIKeyboardWillShowNotification
object:nil];
然后是实现的核心代码
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- (void)didReceiveKeyboardShowNotification:(NSNotification *)noti {
NSDictionary *userInfo = noti.userInfo;
NSTimeInterval animationDuration;
UIViewAnimationCurve animationCurve;
CGRect keyboardFrame;
[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];
[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
[[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardFrame];
UIViewAnimationOptions animationOptions = animationCurve << 16;
self.bottomConstrains.offset = -CGRectGetHeight(keyboardFrame);
[UIView animateWithDuration:animationDuration delay:0. options:animationOptions animations:^{
[self.view setNeedsUpdateConstraints];
[self.view layoutIfNeeded];
} completion:^(BOOL finished) {
}];
}
self.bottomConstrains.offset = -CGRectGetHeight(keyboardFrame); 是我写的约束 详细请参考demo
键盘消失也是一样的 UIKeyboardWillHideNotification 接收这个key
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[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(didReceiveKeyboardHideNotification:)
name:UIKeyboardWillHideNotification
object:nil];
消失的时候 把约束偏移量设置0即可
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- (void)didReceiveKeyboardHideNotification:(NSNotification *)noti {
NSDictionary *userInfo = noti.userInfo;
NSTimeInterval animationDuration;
UIViewAnimationCurve animationCurve;
CGRect keyboardFrame;
[[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];
[[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] getValue:&animationDuration];
[[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardFrame];
UIViewAnimationOptions animationOptions = animationCurve << 16;
self.bottomConstrains.offset = 0;
[UIView animateWithDuration:animationDuration delay:0. options:animationOptions animations:^{
[self.view setNeedsUpdateConstraints];
[self.view layoutIfNeeded];
} completion:^(BOOL finished) {
}];
}
self.bottomConstrains.offset = 0; //设置偏移量会原来位置
利用Masonry做的动画
最后 别忘记移除通知
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- (void)dealloc {
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
总结
键盘弹出这个微小的细节 很容易被大家忽视,写这篇文章是为了记录知识和技巧,希望各位多多指教
全文完