迅速回答:

override func viewDidLoad() {
    super.viewDidLoad()
    let tapGestureReconizer = UITapGestureRecognizer(target: self, action: "tap:")
    view.addGestureRecognizer(tapGestureReconizer)
}

func tap(sender: UITapGestureRecognizer) {
    view.endEditing(true)
}

-(BOOL)textFieldShouldReturn:(UITextField *)textField; // called from textfield (keyboard)

-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text; // good tester function - thanks

在使用uitextview时还有另一个解决方案， 你可以添加工具栏作为InputAccessoryView在“textViewShouldBeginEditing”，并从这个工具栏的完成按钮，你可以解雇键盘，这是如下代码:

在viewDidLoad

toolBar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 44)]; //toolbar is uitoolbar object
toolBar.barStyle = UIBarStyleBlackOpaque;
UIBarButtonItem *btnDone = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(btnClickedDone:)];
[toolBar setItems:[NSArray arrayWithObject:btnDone]];

在textviewdelegate方法

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
     [textView setInputAccessoryView:toolBar];
     return YES;
}

在操作按钮完成，这是在工具栏如下:

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

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;
}

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()
}

问题问的是如何用返回键来做，但我认为这可以帮助那些想要在使用UITextView时让键盘消失的人:

private func addToolBarForTextView() {
    let textViewToolbar: UIToolbar = UIToolbar()
    textViewToolbar.barStyle = .default
    textViewToolbar.items = [
        UIBarButtonItem(title: "Cancel", style: .done,
                  target: self, action: #selector(cancelInput)),
        UIBarButtonItem(barButtonSystemItem: .flexibleSpace,
                  target: self, action: nil),
        UIBarButtonItem(title: "Post Reply", style: .done,
                  target: self, action: #selector(doneInput))
    ]
    textViewToolbar.sizeToFit()
    yourTextView.inputAccessoryView = textViewToolbar
}

@objc func cancelInput() { print("cancel") }
@objc func doneInput() { print("done") }

override func viewDidLoad() {
    super.viewDidLoad()
    addToolBarForTextView()
}

在viewDidLoad或其他生命周期方法中调用addToolBarForTextView()。

这对我来说似乎是一个完美的解决方案。

欢呼,

穆拉特