想在键盘上添加一个按钮，实时根据键盘不同高度变换按钮位置，再不做输入的时候点击按钮能够隐藏键盘，这种方式在很多软件上都有体现，然后在网上查阅了关于检测键盘高度一些相关知识，以下是一个Demo，代码有很多需要优化地方，仅供需要者参考；
- (void)viewDidLoad
{
NSLog(@"%@",NSStringFromSelector(_cmd));
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleKeyboardDidShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleKeyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}
- (void)handleKeyboardDidShow:(NSNotification *)notification
{
NSLog(@"%@",NSStringFromSelector(_cmd));
NSDictionary *info = [notification userInfo];
CGRect keyboardFrame;
[[info objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardFrame];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey]CGRectValue].size;
CGFloat distanceToMove = kbSize.height;
NSLog(@"---->动态键盘高度:%f",distanceToMove);
if (exitButton == nil) {
exitButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
CGRect exitBtFrame = CGRectMake(self.view.frame.size.width-40, self.view.frame.size.height - distanceToMove, 40.0f, 30.0f);
exitButton.frame = exitBtFrame;
[exitButton setImage:[UIImage imageNamed:@"DoneDown.png"] forState:UIControlStateNormal];
[self.view addSubview:exitButton];
}
exitButton.hidden=NO;
[self adjustPanelsWithKeyBordHeight:distanceToMove];
[exitButton addTarget:self action:@selector(CancelBackKeyboard:) forControlEvents:UIControlEventTouchDown];
}
在这一段代码上，后面注释了5行，因为打算当键盘推出的时候，按钮从视图上移除，或者释放按钮，但是都导致了应用程序崩溃，后来就没有释放和移除操作了
- (void)handleKeyboardWillHide:(NSNotification *)notification
{
NSLog(@"%@",NSStringFromSelector(_cmd));
if (exitButton.hidden==NO) {
exitButton.hidden = YES;
}
// if (exitButton.superview)
// {
// [exitButton removeFromSuperview];
// [exitButton release];
// }
}
-(void)adjustPanelsWithKeyBordHeight:(float) height
{
NSLog(@"%@",NSStringFromSelector(_cmd));
if (exitButton) {
CGRect exitBtFrame = CGRectMake(self.view.frame.size.width - 40, self.view.frame.size.height - height-30, 40.0f, 30.0f);
exitButton.frame = exitBtFrame;
[self.view addSubview:exitButton];
}
// UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
// if (exitButton.superview == nil)
// {
// [tempWindow addSubview:exitButton];
// // 注意这里直接加到window上
// }
}
-(void)CancelBackKeyboard:(id)sender
{
NSLog(@"%@",NSStringFromSelector(_cmd));
[textField resignFirstResponder];
}
- (void)viewDidUnload
{
[self setTextField:nil];
exitButton=nil;
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (void)dealloc {
[textField release];
[exitButton release];
[[NSNotificationCenter defaultCenter] removeObserver:self];//移除所注册的通知
[super dealloc];
}
