键盘的使用

1：键盘打开和关闭通知
 //注册键盘关闭打开事件 UIKeyboardWillShowNotification
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(whenKeyboardShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(whenKeyboardHide:) name:UIKeyboardWillHideNotification object:nil];

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2:点击键盘reture让键盘消失
//注册键盘按键委托
//<UITextFieldDelegate>
self.textField.delegate = self;
-(BOOL)textFieldShouldReturn:(UITextField *)textField{
    [self KeyDismiss];
    return true;
}
//让键盘消失
-(void)KeyDismiss{
    [self.textField resignFirstResponder];
}
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3:点击view让键盘消失
//注册view点击后隐藏键盘
[self.view addGestureRecognizer:[[UITapGestureRecognizer alloc]initWithTarget:(self) action:@selector(KeyDismiss)]];

4：键盘出现和隐藏时文本框的和scroll滚动
-(void)whenKeyboardHide:(NSNotification*) notif{
    //获取当前键盘高度
    NSDictionary* info = notif.userInfo;
    NSValue* value = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [value CGRectValue];
    //重设scrollview高度
    [UIView animateWithDuration:0.2f animations:^{
        [self.scrollView setContentOffset:CGPointMake(0,self.prevY-keyboardRect.size.height)];
        [self.textField setFrame:CGRectMake(0,538,320,30)];
    }];
    //若没有scrollview可以使用uiview位移
    //CGAffineTransform myTransform = CGAffineTransformMakeTranslation(0.0, -keyboardRect.size.height/2);
    //[_txt_email setTransform:myTransform];
    //[_txt_pwd setTransform:myTransform];
}
-(void)whenKeyboardShow:(NSNotification*) notif{
    //获取当前键盘高度
    NSDictionary* info = notif.userInfo;
    NSValue* value = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [value CGRectValue];
    
    //重设scrollview高度
   [UIView animateWithDuration:0.1f animations:^{
       [self.scrollView setContentOffset:CGPointMake(0, keyboardRect.size.height)];
       [self.textField setFrame:CGRectMake(0,568-keyboardRect.size.height-30,320,30)];
   }];   
   //若没有scrollview可以使用uiview位移
    //CGAffineTransform myTransform = CGAffineTransformMakeTranslation(0.0, -keyboardRect.size.height/2);
   //[_txt_email setTransform:myTransform];
    //[_txt_pwd setTransform:myTransform];

}