+ (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;
    }
}

我知道这已经回答了，但我真的不喜欢使用字符串字面量的换行，所以这是我所做的。

- (BOOL)textView:(UITextView *)txtView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
    if( [text rangeOfCharacterFromSet:[NSCharacterSet newlineCharacterSet]].location == NSNotFound ) {
        return YES;
    }

    [txtView resignFirstResponder];
    return NO;
}

Swift 4.0更新:

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
if (text as NSString).rangeOfCharacter(from: CharacterSet.newlines).location == NSNotFound {
    return true
}
txtView.resignFirstResponder()
return false
}

对于Swift 3，这段代码允许我在UITextView之外按下键来解除键盘。

@IBOutlet weak var comment: UITextView!

   override func viewDidLoad() {
        super.viewDidLoad()

        comment.delegate = self

        let tapGestureRecogniser = UITapGestureRecognizer(target: self, action: #selector(tap))
        view.addGestureRecognizer(tapGestureRecogniser)
    }

    func tap(sender: UITapGestureRecognizer) {
        if comment.isFirstResponder {
            comment.resignFirstResponder()
        }
    }

你也可以隐藏键盘时，触摸在视图屏幕:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
     UITouch * touch = [touches anyObject];
     if(touch.phase == UITouchPhaseBegan) {
        [txtDetail resignFirstResponder];
      }
 }

斯威夫特

func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
    if text == "\n" {
        textView.resignFirstResponder()
    }
    return true
}

我使用这段代码来更改响应器。

 - (BOOL)textView:(UITextView*) textView shouldChangeTextInRange: (NSRange) range replacementText: (NSString*) text
    {
        if ([text isEqualToString:@"\n"]) {
            //[textView resignFirstResponder];
            //return YES;
            NSInteger nextTag = textView.tag + 1;
            // Try to find next responder
            UIResponder* nextResponder = [self.view viewWithTag:nextTag];
            if (nextResponder) {
                // Found next responder, so set it.
                [nextResponder becomeFirstResponder];
            } else {
                // Not found, so remove keyboard.
                [textView resignFirstResponder];
            }
            return NO; 


            return NO;
        }
        return YES;

    }