iphone - 键盘在 UIScrollView 中隐藏文本字段。如何根据键盘移动文本字段？

Question

我正在开发一个有 15 个文本字段的应用程序。所以我使用 UIScrollView 使滚动成为可能。但是当单击这些文本字段进行编辑时，我的最后五个文本字段隐藏在键盘后面。一旦它们处于编辑模式，如何将这些文本字段移动到键盘上方？同样，它们的文本字段位于 UIScrollView 上。不是 UIView。

Answer 1

尝试TPKeyboardAvoidingScrollView。

只需抓住您已有的滚动视图并将其类更改为TPKeyboardAvoidingScrollView，现在当键盘弹出时，它将调整其大小和偏移量，以便正确显示字段。

我建议这样做，因为当您有复杂的布局（许多文本字段和其他组件）时，手动执行此操作可能会很棘手。这个控件非常简单，并且工作起来就像一个魅力！

Answer 2

这是一些示例代码：

#define kOFFSET_FOR_KEYBOARD 80.0

-(void)keyboardWillShow {
    // Animate the current view out of the way
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)keyboardWillHide {
    if (self.view.frame.origin.y >= 0)
    {
        [self setViewMovedUp:YES];
    }
    else if (self.view.frame.origin.y < 0)
    {
        [self setViewMovedUp:NO];
    }
}

-(void)textFieldDidBeginEditing:(UITextField *)sender
{
    if ([sender isEqual:mailTf])
    {
        //move the main view, so that the keyboard does not hide it.
        if  (self.view.frame.origin.y >= 0)
        {
            [self setViewMovedUp:YES];
        }
    }
}

//method to move the view up/down whenever the keyboard is shown/dismissed
-(void)setViewMovedUp:(BOOL)movedUp
{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3]; // if you want to slide up the view

    CGRect rect = self.view.frame;
    if (movedUp)
    {
        // 1. move the view's origin up so that the text field that will be hidden come above the keyboard 
        // 2. increase the size of the view so that the area behind the keyboard is covered up.
        rect.origin.y -= kOFFSET_FOR_KEYBOARD;
        rect.size.height += kOFFSET_FOR_KEYBOARD;
    }
    else
    {
        // revert back to the normal state.
        rect.origin.y += kOFFSET_FOR_KEYBOARD;
        rect.size.height -= kOFFSET_FOR_KEYBOARD;
    }
    self.view.frame = rect;

    [UIView commitAnimations];
}


- (void)viewWillAppear:(BOOL)animated
{
    // register for keyboard notifications
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

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

- (void)viewWillDisappear:(BOOL)animated
{
    // unregister for keyboard notifications while not visible.
    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillShowNotification
                                           object:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                             name:UIKeyboardWillHideNotification
                                           object:nil];
}

Answer 3

你可以减少你的scrollView Y坐标textFieldShouldBeginEditing:

-(BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
   if(textField == textField11 || textField == textField12 || textField == textField13 || textField == textField14 || textField == textField15)
   {   
       [UIView beginAnimations:nil context:NULL];
       [UIView setAnimationDuration:0.3];
       //set Y according to keyBoard height
       [scrollView setFrame:CGRectMake(0.0,-220.0,320.0,460.0)];
       [UIView commitAnimations];
   }
}

并按键盘的返回键设置scrollView框架

-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];
    [scrollView setFrame:CGRectMake(0.0,0.0,320.0,460.0)];
    [UIView commitAnimations];   
}

Answer 4

您需要在 scrollView 上相应地设置 contentSize 和 contentOffset。因此，如果您的最后一个文本框的原点为 (0,300)，您可能希望 contentSize 为 CGSizeMake(0, 600) 左右，然后将 contentOffset 设置为 (0, 250)。