Objective c 在代码中将方法分配给UITextField

我的视图底部有一个文本字段。当你点击编辑它时，键盘会把它盖起来，你看不到你正在输入什么。我想创建一个方法，每当编辑此文本字段时，该方法将重新调整视图

如果我通过interface builder声明了textfield，那么我知道我所要做的就是链接（ctrl单击然后拖动）它。但是我在代码中声明了textfield，所以我想知道如何为它分配一个方法

我想做的伪代码：

if (the text field is currently being edited){
    call method: adjust view
}

---

您必须为文本视图指定一个代理：

[textView setDelegate: self]

---

我假设，

self

是您的视图控制器，它需要符合。文本视图在开始编辑循环时将调用

textViewShouldBeginEditing:

/

textViewWillBeginEditing

。

您必须为文本视图分配一个代理：

[textView setDelegate: self]

---

我假设，

self

是您的视图控制器，它需要符合。文本视图在开始编辑循环时将调用

textViewShouldBeginEditing:

/

textViewWillBeginEditing

。

创建文本字段时，将其委托设置为self

[textField setDelegate:self];

然后实现委托方法

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    //adjust view here
}

- (void)textFieldDidEndEditing:(UITextField *)textField {
    //move view back to correct position here
}

---

您还可以注册UIKeyboardWillShow/UIKeyboardWillHide或UIKeyboardDidShow/UIKeyboardDidHide消息，并实现相应的功能。

创建文本字段时，将其委托设置为self

[textField setDelegate:self];

然后实现委托方法

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    //adjust view here
}

- (void)textFieldDidEndEditing:(UITextField *)textField {
    //move view back to correct position here
}

---

您还可以注册UIKeyboardWillShow/UIKeyboardWillHide或UIKeyboardDidShow/UIKeyboardDidHide消息，并实现相应的功能。

在.h中实现UIExtFieldDelegate，如下所示：

@interface ShippingInfoViewController:UIViewController

并确保将文本字段的委托设置为

self

然后您可以访问许多方法，例如

-（BOOL）textField:（UITextField*）textField应更改字符范围：（NSRange）范围替换字符串：（NSString*）字符串{

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

-（BOOL）textField应该返回：（UITextField*）textField{

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

还有很多其他的

---

在.h中实现UITextFieldDelegate，如下所示：

@interface ShippingInfoViewController:UIViewController

并确保将文本字段的委托设置为

self

然后您可以访问许多方法，例如

-（BOOL）textField:（UITextField*）textField应更改字符范围：（NSRange）范围替换字符串：（NSString*）字符串{

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

-（BOOL）textField应该返回：（UITextField*）textField{

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

还有很多其他的

---

使用以下功能：

- (void)viewWillAppear:(BOOL)animated
{
   [super viewWillAppear:animated];

   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];

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


- (void)keyboardWillShow:(NSNotification *)notification
{  
  [self moveTextViewForKeyboard:notification up:YES];
}


- (void)keyboardWillHide:(NSNotification *)notification
{
  [self moveTextViewForKeyboard:notification up:NO];
}


- (void)moveTextViewForKeyboard:(NSNotification*)notification up:(BOOL)up {
   NSDictionary *userInfo = [notification userInfo];
   NSTimeInterval animationDuration;
   UIViewAnimationCurve animationCurve;
   CGRect keyboardRect;

  [[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];
  animationDuration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
  keyboardRect = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
  keyboardRect = [self.view convertRect:keyboardRect fromView:nil];

  [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
  [UIView setAnimationDuration:animationDuration];
  [UIView setAnimationCurve:animationCurve];

 if (up == YES) {
    CGFloat keyboardTop = keyboardRect.origin.y;
    CGRect newTextViewFrame = self.noteTextView.frame;
    originalTextViewFrame = self.noteTextView.frame;
    newTextViewFrame.size.height = keyboardTop - self.noteTextView.frame.origin.y - 10;

    self.noteTextView.frame = newTextViewFrame;
 } else {
    // Keyboard is going away (down) - restore original frame
    self.noteTextView.frame = originalTextViewFrame;
 }

  [UIView commitAnimations];
}

对originalTextViewFrame使用静态变量：

static CGRect originalTextViewFrame;

---

使用以下功能：

- (void)viewWillAppear:(BOOL)animated
{
   [super viewWillAppear:animated];

   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];

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


- (void)keyboardWillShow:(NSNotification *)notification
{  
  [self moveTextViewForKeyboard:notification up:YES];
}


- (void)keyboardWillHide:(NSNotification *)notification
{
  [self moveTextViewForKeyboard:notification up:NO];
}


- (void)moveTextViewForKeyboard:(NSNotification*)notification up:(BOOL)up {
   NSDictionary *userInfo = [notification userInfo];
   NSTimeInterval animationDuration;
   UIViewAnimationCurve animationCurve;
   CGRect keyboardRect;

  [[userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] getValue:&animationCurve];
  animationDuration = [[userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
  keyboardRect = [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
  keyboardRect = [self.view convertRect:keyboardRect fromView:nil];

  [UIView beginAnimations:@"ResizeForKeyboard" context:nil];
  [UIView setAnimationDuration:animationDuration];
  [UIView setAnimationCurve:animationCurve];

 if (up == YES) {
    CGFloat keyboardTop = keyboardRect.origin.y;
    CGRect newTextViewFrame = self.noteTextView.frame;
    originalTextViewFrame = self.noteTextView.frame;
    newTextViewFrame.size.height = keyboardTop - self.noteTextView.frame.origin.y - 10;

    self.noteTextView.frame = newTextViewFrame;
 } else {
    // Keyboard is going away (down) - restore original frame
    self.noteTextView.frame = originalTextViewFrame;
 }

  [UIView commitAnimations];
}

对originalTextViewFrame使用静态变量：

static CGRect originalTextViewFrame;

---

在我的.h文件中，我的接口声明如下

@interface SecondDetailViewController:UIViewController

当我将文本字段的委托设置为自身时，它会在运行时崩溃，有什么想法吗？你是怎么做的？文本字段是在序列图像板中还是在代码中？我通常通过单击控件（或右键单击）在序列图像板中执行此操作从字段到文件所有者（底部的黄色框）并选择委派。在代码中，它应该是

textField.delegate=self；

我发现了问题；我在分配前设置了委派。不过感谢您的响应。在我的.h文件中，当我设置textfi时，我的接口声明如下

@interface SecondDetailViewController:UIViewController

eld对自身的委托在运行时崩溃，有什么想法吗？你是怎么做到的？文本字段是在情节提要中还是在代码中？我通常在情节提要中通过从字段到文件所有者（底部的黄色框）的控制单击（或右键单击）来完成此操作然后选择委派。在代码中，它应该是

textField.delegate=self；

我发现了问题；我在分配前设置了委派。不过谢谢你的回答。@user1458968这是非常正确的；但是我怎么知道呢？我的答案是第一个：-）没关系。@user1458968这是非常正确的；但是我怎么知道呢现在呢？我的答案是第一个：-）没关系。