键盘滚动到当前文本框和按return隐藏

标签：ios   objective-c   

-(void) viewWillAppear:(BOOL)animated {
    
    //注册键盘出现通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector (keyboardDidshow:)
                                                 name: UIKeyboardDidShowNotification object:nil];
    //注册键盘隐藏通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector (keyboardDidHide:)
                                                 name: UIKeyboardDidHideNotification object:nil];
    [super viewWillAppear:animated];
}


-(void) viewWillDisappear:(BOOL)animated {
    //解除键盘出现通知
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name: UIKeyboardDidShowNotification object:nil];
    //解除键盘隐藏通知
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name: UIKeyboardDidHideNotification object:nil];
    
    [super viewWillDisappear:animated];
}
-(void) keyboardDidshow: (NSNotification *)notif {
    if (keyboardVisible) {
        return; // 键盘出现时，忽略通知
    }
    
    // 获得键盘尺寸
    NSDictionary *info = [notif userInfo];
    NSValue *aValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGSize keyboardSize = [aValue CGRectValue].size;
    
    // 重新定义SrollView的尺寸
    CGRect viewFrame = [self.scrollView frame];
    viewFrame.size.height -= keyboardSize.height;
    self.scrollView.frame = viewFrame;
    
    // 滚动到当前文本框
    // frame方法可以当前控件的结构体数据
    CGRect textFieldRect = [self.textField frame];
    // 指定滚动到一个矩形区域
    [self.scrollView scrollRectToVisible:textFieldRect animated:YES];
    keyboardVisible = YES;
}

- (void) keyboardDidHide: (NSNotification *)notif{
    
    // 获得键盘尺寸
    NSDictionary *info = [notif userInfo];
    NSValue *aValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGSize keyboardSize = [aValue CGRectValue].size;
    
    // 重新定义SrollView的尺寸
    CGRect viewFrame = [self.scrollView frame];
    viewFrame.size.height += keyboardSize.height;
    self.scrollView.frame = viewFrame;
    
    if (!keyboardVisible) {
        return;
    }
    keyboardVisible = NO;
}

-(BOOL) textFieldShouldReturn:(UITextField *)textField
{
    // 当按下return时，键盘消失
    [textField resignFirstResponder];
    return YES;
}

键盘滚动到当前文本框和按return隐藏

标签：ios   objective-c   

原文地址：http://blog.csdn.net/liyakun1990/article/details/40296235