在你的视图控制器的头文件中添加<UITextFieldDelegate>到你的控制器接口的定义中，以便它符合UITextField委托协议…

@interface someViewController : UIViewController <UITextFieldDelegate>

．.． 在控制器的实现文件(.m)中添加以下方法，或者如果你已经有一个viewDidLoad方法，则在其中添加代码…

- (void)viewDidLoad
{
    // Do any additional setup after loading the view, typically from a nib.
    self.yourTextBox.delegate = self;
}

．.． 然后，链接你的文本框到你的实际文本字段

- (BOOL)textFieldShouldReturn:(UITextField *)theTextField 
{
    if (theTextField == yourTextBox) {
        [theTextField resignFirstResponder];
    }
    return YES;
}

这不是很漂亮，但是当我不知道responder是什么时，我辞去firstResponder的方式:

创建一个UITextField，无论是在IB或编程。把它隐藏起来。如果你是用IB写的，就把它链接到你的代码上。 然后，当你想要解散键盘时，你将响应器切换到不可见的文本字段，并立即辞职:

  [self.invisibleField becomeFirstResponder];
  [self.invisibleField resignFirstResponder];

最简单的方法是调用方法

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{
    if(![txtfld resignFirstResponder])
    {
        [txtfld resignFirstResponder];
    }
    else
    {

    }
    [super touchesBegan:touches withEvent:event];
}

把这个藏在实用课里吧。

+ (void)dismissKeyboard {
    [self globalResignFirstResponder];
}

+ (void) globalResignFirstResponder {
    UIWindow * window = [[UIApplication sharedApplication] keyWindow];
    for (UIView * view in [window subviews]){
        [self globalResignFirstResponderRec:view];
    }
}

+ (void) globalResignFirstResponderRec:(UIView*) view {
    if ([view respondsToSelector:@selector(resignFirstResponder)]){
        [view resignFirstResponder];
    }
    for (UIView * subview in [view subviews]){
        [self globalResignFirstResponderRec:subview];
    }
}

杰里米的回答不太适合我，我想是因为我在一个选项卡视图中有一个导航堆栈，上面有一个模态对话框。我现在使用下面的，它是为我工作，但你的里程可能会有所不同。

 // dismiss keyboard (mostly macro)
[[UIApplication sharedApplication].delegate dismissKeyboard]; // call this in your to app dismiss the keybaord

// --- dismiss keyboard (in indexAppDelegate.h) (mostly macro)
- (void)dismissKeyboard;

// --- dismiss keyboard (in indexAppDelegate.m) (mostly macro)
// do this from anywhere to dismiss the keybard
- (void)dismissKeyboard {    // from: http://stackoverflow.com/questions/741185/easy-way-to-dismiss-keyboard

    UITextField *tempTextField = [[UITextField alloc] initWithFrame:CGRectZero];

    UIViewController *myRootViewController = <#viewController#>; // for simple apps (INPUT: viewController is whatever your root controller is called.  Probably is a way to determine this progragrammatically)
    UIViewController *uivc;
    if (myRootViewController.navigationController != nil) { // for when there is a nav stack
        uivc = myRootViewController.navigationController;
    } else {
        uivc = myRootViewController;
    }

    if (uivc.modalViewController != nil) { // for when there is something modal
        uivc = uivc.modalViewController;
    } 

    [uivc.view  addSubview:tempTextField];

    [tempTextField becomeFirstResponder];
    [tempTextField resignFirstResponder];
    [tempTextField removeFromSuperview];
    [tempTextField release];

}

你可以向应用程序发送一个nil目标动作，它会在任何时候辞职第一响应者，而不必担心哪个视图当前有第一响应者状态。

objective - c:

[[UIApplication sharedApplication] sendAction:@selector(resignFirstResponder) to:nil from:nil forEvent:nil];

斯威夫特3.0:

UIApplication.shared.sendAction(#selector(resignFirstResponder), to: nil, from: nil, for: nil)

在Mac OS X中，Nil目标操作在菜单命令中很常见，在iOS中也有使用。