+ (void)addDoneButtonToControl:(id)txtFieldOrTextView
{
    if([txtFieldOrTextView isKindOfClass:[UITextField class]])
    {
        txtFieldOrTextView = (UITextField *)txtFieldOrTextView;
    }
    else if([txtFieldOrTextView isKindOfClass:[UITextView class]])
    {
        txtFieldOrTextView = (UITextView *)txtFieldOrTextView;
    }

    UIToolbar* numberToolbar = [[UIToolbar alloc]initWithFrame:CGRectMake(0,
                                                                          0,
                                                                          [Global returnDeviceWidth],
                                                                          50)];
    numberToolbar.barStyle = UIBarStyleDefault;


    UIBarButtonItem *btnDone = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"btn_return"]
                                                                style:UIBarButtonItemStyleBordered
                                                               target:txtFieldOrTextView
                                                               action:@selector(resignFirstResponder)];

    numberToolbar.items = [NSArray arrayWithObjects:btnDone,nil];
    [numberToolbar sizeToFit];

    if([txtFieldOrTextView isKindOfClass:[UITextField class]])
    {
         ((UITextField *)txtFieldOrTextView).inputAccessoryView = numberToolbar;
    }
    else if([txtFieldOrTextView isKindOfClass:[UITextView class]])
    {
         ((UITextView *)txtFieldOrTextView).inputAccessoryView = numberToolbar;
    }
}

就像matt对samvermette的评论一样，我也不喜欢检测“\n”的想法。返回键在UITextView中是有原因的，当然是去下一行。

在我看来，最好的解决方案是模仿iPhone的消息应用程序-这是在键盘上添加工具栏(和按钮)。

我从以下博客文章中得到了代码:

http://www.iosdevnotes.com/2011/02/iphone-keyboard-toolbar/

步骤:

-添加工具栏到你的XIB文件-设置高度为460

-添加工具栏按钮项(如果尚未添加)。如果需要右对齐，还可以将灵活的工具栏按钮项添加到XIB，并移动工具栏按钮项

-创建将按钮项目链接到resignFirstResponder的动作，如下所示:

- (IBAction)hideKeyboard:(id)sender {
    [yourUITextView resignFirstResponder];
}

套:

- (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)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];

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

- (void)keyboardWillShow:(NSNotification *)notification {
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];

    CGRect frame = self.keyboardToolbar.frame;
    frame.origin.y = self.view.frame.size.height - 260.0;
    self.keyboardToolbar.frame = frame;

    [UIView commitAnimations];
}

- (void)keyboardWillHide:(NSNotification *)notification {
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.3];

    CGRect frame = self.keyboardToolbar.frame;
    frame.origin.y = self.view.frame.size.height;
    self.keyboardToolbar.frame = frame;

    [UIView commitAnimations];
}

好的。每个人都用技巧给出了答案，但我认为实现这一点的正确方法是

将以下操作连接到接口生成器中的“Did End On Exit”事件。 (右键单击TextField并从“Did end on exit”中cntrl-drag到以下方法。

-(IBAction)hideTheKeyboard:(id)sender
{
    [self.view endEditing:TRUE];
}

不要忘记为textView设置委托-否则resignfirstresponder将无法工作。

-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
    if([text isEqualToString:@"\n"])
        [textView resignFirstResponder];
    return YES;
}

yourtextView.delegate=self;

还要添加UITextViewDelegate

别忘了确认协议

如果你没有添加IF ([text isEqualToString:@"\n"])，你就不能编辑

使用导航控制器托管一个栏来解除键盘:

在.h文件中:

UIBarButtonItem* dismissKeyboardButton;

在.m文件中:

- (void)viewDidLoad {
    dismissKeyboardButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(dismissKeyboard)];
}

-(void)textViewDidBeginEditing:(UITextView *)textView {
    self.navigationItem.rightBarButtonItem = dismissKeyboardButton;
}

-(void)textFieldDidBeginEditing:(UITextField *)textField {
    self.navigationItem.rightBarButtonItem = dismissKeyboardButton;
}

-(void)dismissKeyboard {
    [self.textField resignFirstResponder];
    [self.textView resignFirstResponder];
    //or replace this with your regular right button
    self.navigationItem.rightBarButtonItem = nil;
}