Question

当键盘覆盖文本字段时，我使用代码使屏幕滚动。

我有一个文本字段列表，我开始将每个文本域放在自己的uiview中以用于样式和组织目的。

现在我的代码只有在我开始实际输入文本字段时才有效。这是我从苹果复制的怪物。注意：我添加了一个参数 registerForKeyboardNotifications，以便我可以将其包含在父类中并从任何地方调用

  // Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications:(UIScrollView *)scroll
{
    _scroller = scroll;

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}

// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSLog(@"hey");
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    _scroller.contentInset = contentInsets;
    _scroller.scrollIndicatorInsets = contentInsets;

    // If active text field is hidden by keyboard, scroll it so it's visible
    // Your application might not need or want this behavior.
    CGRect aRect = self.view.frame;
    aRect.size.height -= kbSize.height;
    if (!CGRectContainsPoint(aRect, _activeField.frame.origin) ) {
        CGPoint scrollPoint = CGPointMake(0.0, _activeField.frame.origin.y-kbSize.height);
        [_scroller setContentOffset:scrollPoint animated:YES];
    }
}

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;
    _scroller.contentInset = contentInsets;
    _scroller.scrollIndicatorInsets = contentInsets;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField{

    _activeField = textField;
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    _activeField = nil;
}

我已将问题缩小到viewcontroller中的这一部分

    for (id subView in _tpnScroll.subviews)
{

    if ([subView isKindOfClass:[UIView class]]) {
        UIView *thisView = subView;
        for(id textfield in thisView.subviews){
            if([textfield isKindOfClass:[UITextField class]]){
                [textfield setDelegate:self];
            }
        }
    }
}

原始代码是

    for (id subView in _tpnScroll.subviews){
    if ([subView isKindOfClass:[UITextField class]]) {
        [subView setDelegate:self];
    }
}

第一个例子中的

。我循环遍历我的UIViews，找到UITextfields，并将委托设置为self（这部分我不完全理解，仍然试图理解委托的概念）

在第二个例子中，文本字段直接位于scrollview上，所以我只是直接遍历它们。

抱歉，如果这很罗嗦。

Answer 1

尝试用此替换keyboardWasShown。

- (void)keyboardWasShown:(NSNotification*)aNotification
{
    NSLog(@"hey");
    NSDictionary* info = [aNotification userInfo];
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
    _scroller.contentInset = contentInsets;
    _scroller.scrollIndicatorInsets = contentInsets;

    // the scroll view will only scroll if the text field is not fully visible
    // no need to check if it is actually covered
    [_scroller scrollRectToVisible:[_scroller convertRect:_activeField.bounds fromView:_activeField]
                        animated:YES];
}

将文本字段的边界转换为滚动视图的坐标系，确保文本字段位于滚动视图内，即使它不在其中，也可以正常工作。

iOS - 当文本字段位于子视图内时，UIScroll键盘弹出到文本字段

1 个答案: