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。所以我用UIScrollView使滚动成为可能。但是当点击那些文本字段进行编辑时，我最后的五个文本字段隐藏在键盘后面。一旦他们处于编辑模式，如何将这些文本字段移动到键盘上方？同样，他们的文本字段在UIScrollView上。不是UIView。

Answer 1

您需要在scrollView上相应地设置contentSize和contentOffset。所以如果你的最后一个文本框的起始位置是（0,300），你可能会希望你的contentSize是CGSizeMake（0,600）左右，然后将你的contentOffset设置为（0,250）。

Answer 2

尝试TPKeyboardAvoidingScrollView。

只要抓住你已经滚动视图，并改变它的类TPKeyboardAvoidingScrollView，现在当键盘弹出，它会调整它的大小和偏移，这样的字段正确显示。

我建议这样做，因为当你有复杂的布局（很多文本字段和其他组件）时，手工操作可能会非常棘手。这个控制就像它的魅力一样简单！

Answer 3

您可以降低scrollViewŸ在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]; 
    } 
} 

协调，并设置scrollView框架，因为它是当你按下回报键盘

-(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

这里的关键是一些示例代码：

#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]; 
}