使用iOS SDK：
我有一个带UITextFields的UIView，可以启动键盘。我需要它能够：
启动键盘后，允许滚动UIScrollView的内容以查看其他文本字段自动“跳转”（通过向上滚动）或缩短
我知道我需要一个UIScrollView。我已经尝试将UIView的类更改为UIScrollView，但仍然无法上下滚动文本框。
我需要UIView和UIScrollView吗？一个在另一个里面吗？
要自动滚动到活动文本字段，需要执行哪些操作？
理想情况下，尽可能多的组件设置将在Interface Builder中完成。我只想编写需要的代码。
注意：我使用的UIView（或UIScrollView）是由一个选项卡（UITabBar）启动的，它需要正常工作。
我正在添加滚动条，只为键盘出现时使用。尽管不需要它，但我觉得它提供了一个更好的界面，例如，用户可以滚动和更改文本框。
当键盘上下移动时，我可以改变UIScrollView的框架大小。我只是在使用：
-(void)textFieldDidBeginEditing:(UITextField *)textField {
//Keyboard becomes visible
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height - 215 + 50); // Resize
}
-(void)textFieldDidEndEditing:(UITextField *)textField {
// Keyboard will hide
scrollView.frame = CGRectMake(scrollView.frame.origin.x,
scrollView.frame.origin.y,
scrollView.frame.size.width,
scrollView.frame.size.height + 215 - 50); // Resize
}
然而，这不会自动“向上移动”或将可见区域中的下部文本字段居中，这是我真正想要的。
在这里，我找到了处理键盘的最简单的解决方案。
您只需复制粘贴到示例代码下面，然后更改文本字段或任何要向上移动的视图。
步骤-1
只需在控制器中复制粘贴以下两种方法
- (void)registerForKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillBeHidden:)
name:UIKeyboardWillHideNotification object:nil];
}
- (void)deregisterFromKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidHideNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}
步骤-2
在视图中注册和注销键盘通知WillAppear和viewWillDisappear方法。
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self registerForKeyboardNotifications];
}
- (void)viewWillDisappear:(BOOL)animated
{
[self deregisterFromKeyboardNotifications];
[super viewWillDisappear:animated];
}
步骤-3
灵魂部分来了，只要替换你的文本字段，然后改变高度你想向上移动多少。
- (void)keyboardWasShown:(NSNotification *)notification
{
NSDictionary* info = [notification userInfo];
CGSize currentKeyboardSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
//you need replace your textfield instance here
CGPoint textFieldOrigin = self.tokenForPlaceField.frame.origin;
CGFloat textFieldHeight = self.tokenForPlaceField.frame.size.height;
CGRect visibleRect = self.view.frame;
visibleRect.size.height -= currentKeyboardSize.height;
if (!CGRectContainsPoint(visibleRect, textFieldOrigin))
{
//you can add yor desired height how much you want move keypad up, by replacing "textFieldHeight" below
CGPoint scrollPoint = CGPointMake(0.0, textFieldOrigin.y - visibleRect.size.height + textFieldHeight); //replace textFieldHeight to currentKeyboardSize.height, if you want to move up with more height
[self.scrollView setContentOffset:scrollPoint animated:YES];
}
}
- (void)keyboardWillBeHidden:(NSNotification *)notification
{
[self.scrollView setContentOffset:CGPointZero animated:YES];
}
参考：好吧，请感谢这位分享了这个漂亮的代码片段、干净的解决方案的人。
希望这对外面的人会很有帮助。
注意：此答案假设您的textField位于scrollView中。
我更喜欢使用scrollContentInset和scrollContentOffset来处理这个问题，而不是干扰视图的框架。
首先让我们听听键盘通知
//call this from viewWillAppear
-(void)addKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillShow:)
name:UIKeyboardWillShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillHide:)
name:UIKeyboardWillHideNotification
object:nil];
}
//call this from viewWillDisappear
-(void)removeKeyboardNotifications{
[[NSNotificationCenter default
Center] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
}
下一步是保留表示当前第一响应者的属性（当前具有键盘的UITextfield/UUITextVIew）。
我们使用委托方法来设置此属性。如果您正在使用另一个组件，则需要类似的组件。
请注意，对于textfield，我们在didBegginEditing中设置它，而对于textView，我们在shouldBeginEditing中将其设置。这是因为出于某种原因，在UIKeyboardWillShowNotification之后调用textViewDidBegginEditing。
-(BOOL)textViewShouldBeginEditing:(UITextView * )textView{
self.currentFirstResponder = textView;
return YES;
}
-(void)textFieldDidBeginEditing:(UITextField *)textField{
self.currentFirstResponder = textField;
}
最后，这里是魔术
- (void)keyboardWillShow:(NSNotification*)aNotification{
NSDictionary* info = [aNotification userInfo];
CGRect kbFrame = [[info objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
/*if currentFirstResponder is overlayed by the keyboard, move it so it bottom ends where the keyboard begins*/
if(self.currentFirstResponder){
//keyboard origin in currentFirstResponderFrame
CGPoint keyboardOrigin = [self.currentFirstResponder convertPoint:kbFrame.origin fromView:nil];
float spaceBetweenFirstResponderAndKeyboard = abs(self.currentFirstResponder.frame.size.height-keyboardOrigin.y);
//only scroll the scrollview if keyboard overlays the first responder
if(spaceBetweenFirstResponderAndKeyboard>0){
//if i call setContentOffset:animate:YES it behaves differently, not sure why
[UIView animateWithDuration:0.25 animations:^{
[self.scrollView setContentOffset:CGPointMake(0,self.scrollView.contentOffset.y+spaceBetweenFirstResponderAndKeyboard)];
}];
}
}
//set bottom inset to the keyboard height so you can still scroll the whole content
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbFrame.size.height, 0.0);
_scrollView.contentInset = contentInsets;
_scrollView.scrollIndicatorInsets = contentInsets;
}
- (void)keyboardWillHide:(NSNotification*)aNotification{
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
_scrollView.contentInset = contentInsets;
_scrollView.scrollIndicatorInsets = contentInsets;
}
从以下链接下载TPKeyBoardAvoiding：https://github.com/michaeltyson/TPKeyboardAvoiding. 展开zipped文件夹，找到TPKeyboardAvoiding文件夹。选择所有.h和.m文件，并将其放到项目中。确保选中了复制项（如果需要）。将UIScrollView拖放到StoryBoard并与TPKeyboardAvoidingScrollView关联。现在，您可以在滚动视图的顶部添加UI元素。注意，即使在拖动scrollView之后，这个类也会检测UI元素的触摸。
在ViewController上：
@IBOutlet weak var usernameTextfield: UITextField!
@IBOutlet weak var passwordTextfield: UITextField!
@IBOutlet weak var loginScrollView: UIScrollView!
override func viewWillAppear(animated: Bool) {
loginScrollView.scrollEnabled = false
}
添加TextField委托。
//MARK:- TEXTFIELD METHODS
func textFieldShouldReturn(textField: UITextField) -> Bool
{
if (usernameTextfield.resignFirstResponder())
{
passwordTextfield.becomeFirstResponder()
}
textField.resignFirstResponder();
loginScrollView!.setContentOffset(CGPoint.zero, animated: true);
loginScrollView.scrollEnabled = false
return true
}
func textFieldDidBeginEditing(textField: UITextField)
{
loginScrollView.scrollEnabled = true
if (textField.tag == 1 && (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch"))
{
let scrollPoint:CGPoint = CGPointMake(0, passwordTextfield.frame.origin.y/6.4);
loginScrollView!.setContentOffset(scrollPoint, animated: true);
}
else if (textField.tag == 2 && (device == "iPhone" || device == "iPhone Simulator" || device == "iPod touch"))
{
let scrollPoint:CGPoint = CGPointMake(0, passwordTextfield.frame.origin.y/6.0);
loginScrollView!.setContentOffset(scrollPoint, animated: true);
}
}
func textFieldDidEndEditing(textField: UITextField)
{
loginScrollView!.setContentOffset(CGPointZero,animated: true);
}
