我发现josebama的回答是这个帖子中最完整、最干净的答案。

下面是Swift 4的语法:

func textView(_ textView: UITextView, shouldChangeTextIn _: NSRange, replacementText text: String) -> Bool {
    let resultRange = text.rangeOfCharacter(from: CharacterSet.newlines, options: .backwards)
    if text.count == 1 && resultRange != nil {
        textView.resignFirstResponder()
        // Do any additional stuff here
        return false
    }
    return true
}

在视图控制器中添加这个方法。

迅速:

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

这个方法对你也有帮助:

/**
Dismiss keyboard when tapped outside the keyboard or textView

:param: touches the touches
:param: event   the related event
*/
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
    if let touch = touches.anyObject() as? UITouch {
        if touch.phase == UITouchPhase.Began {
            textField?.resignFirstResponder()
        }
    }
}

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
}

+ (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;
    }
}

试试这个:

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

    return YES;

}

你应该添加UIToolbar到顶部UITextView，而不是使用shouldChangeTextIn

在Swift 4中

let toolbar = UIToolbar(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: 50))
        toolbar.barStyle = .default
        toolbar.items = [
            UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil),
            UIBarButtonItem(title: "Done", style: .done, target: self, action: #selector(doneAction))
        ]
        textView.inputAccessoryView = toolbar

@objc func doneAction(){
 self.textView.resignFirstResponder()
}