Swift 4 for mxcl答案:

txtFirstname.addTarget(txtLastname, action: 
#selector(becomeFirstResponder), for: UIControlEvents.editingDidEndOnExit)

下面是一个没有授权的例子:

tf1.addTarget(tf2, action: #selector(becomeFirstResponder), for: .editingDidEndOnExit)
tf2.addTarget(tf3, action: #selector(becomeFirstResponder), for: .editingDidEndOnExit)

ObjC:

[tf1 addTarget:tf2 action:@selector(becomeFirstResponder) forControlEvents:UIControlEventEditingDidEndOnExit];
[tf2 addTarget:tf3 action:@selector(becomeFirstResponder) forControlEvents:UIControlEventEditingDidEndOnExit];

使用UIControlEventEditingDidEndOnExit UITextField动作工作(大部分是未知的)。

您还可以很容易地将其连接到故事板中，因此不需要委托或代码。

编辑:实际上我不知道如何在故事板中连接这个。becomeFirstResponder似乎不是这个control-event的一个提供的动作，这是一个遗憾。尽管如此，你可以将所有的文本字段连接到你的ViewController中的一个动作，然后决定哪个textField成为基于发送者的firstresponder(虽然它不像上面的编程解决方案那么优雅，所以IMO用viewDidLoad中的上述代码来做)。

这是一个简单的解决方案在swift，没有标签使用，没有故事板技巧…

只需使用这个扩展:

extension UITextField{

    func nextTextFieldField() -> UITextField?{
        //field to return
        var returnField : UITextField?
        if self.superview != nil{
            //for each view in superview
            for (_, view) in self.superview!.subviews.enumerate(){
                //if subview is a text's field
                if view.isKindOfClass(UITextField){
                    //cast curent view as text field
                    let currentTextField = view as! UITextField
                    //if text field is after the current one
                    if currentTextField.frame.origin.y > self.frame.origin.y{
                        //if there is no text field to return already
                        if returnField == nil {
                            //set as default return
                            returnField = currentTextField
                        }
                            //else if this this less far than the other
                        else if currentTextField.frame.origin.y < returnField!.frame.origin.y{
                            //this is the field to return
                            returnField = currentTextField
                        }
                    }
                }
            }
        }
        //end of the mdethod
        return returnField
    }

}

并调用它像这样(例如)与你的textfield委托:

func textFieldShouldReturn(textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    textField.nextTextFieldField()?.becomeFirstResponder()
    return true
}

一个快速扩展，应用mxcl的答案，使这特别容易(适应swift 2.3由旅行者):

extension UITextField {
    class func connectFields(fields:[UITextField]) -> Void {
        guard let last = fields.last else {
            return
        }
        for i in 0 ..< fields.count - 1 {
            fields[i].returnKeyType = .Next
            fields[i].addTarget(fields[i+1], action: "becomeFirstResponder", forControlEvents: .EditingDidEndOnExit)
        }
        last.returnKeyType = .Done
        last.addTarget(last, action: #selector(UIResponder.resignFirstResponder), forControlEvents: .EditingDidEndOnExit)
    }
}

它很容易使用:

UITextField.connectFields([field1, field2, field3])

扩展将设置返回按钮为“下一步”为所有但最后一个字段和“完成”为最后一个字段，并转移焦点/解散键盘时，这些被轻敲。

Swift < 2.3

extension UITextField {
    class func connectFields(fields:[UITextField]) -> Void {
        guard let last = fields.last else {
            return
        }
        for var i = 0; i < fields.count - 1; i += 1 {
            fields[i].returnKeyType = .Next
            fields[i].addTarget(fields[i+1], action: "becomeFirstResponder", forControlEvents: .EditingDidEndOnExit)
        }
        last.returnKeyType = .Done
        last.addTarget(last, action: "resignFirstResponder", forControlEvents: .EditingDidEndOnExit)
    }
}

斯威夫特3: 像这样使用-

UITextField.connectFields(fields: [field1, field2])

Extension:
    extension UITextField {
        class func connectFields(fields:[UITextField]) -> Void {
            guard let last = fields.last else {
                return
            }
            for i in 0 ..< fields.count - 1 {
                fields[i].returnKeyType = .next
                fields[i].addTarget(fields[i+1], action: #selector(UIResponder.becomeFirstResponder), for: .editingDidEndOnExit)
            }
            last.returnKeyType = .go
            last.addTarget(last, action: #selector(UIResponder.resignFirstResponder), for: .editingDidEndOnExit)
        }
    }

首先在xib中设置键盘返回键，否则你可以在viewdidload中编写代码:

passWord.returnKeyType = UIReturnKeyNext;

-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    if(textField == eMail) {
        [textField resignFirstResponder];
        [userName becomeFirstResponder];
    }
    if (textField==userName) {
        [textField resignFirstResponder];
        [passWord becomeFirstResponder];
    }
    if (textField==passWord) {
        [textField resignFirstResponder];
        [country becomeFirstResponder];
    }
    if (textField==country) {
        [textField resignFirstResponder];
    }
    return YES;
}

我尝试使用一种更复杂的方法来解决这个问题，该方法基于为UITableView中的每个单元格(或UITextField)分配一个稍后可以检索的唯一标签值: activate-next-uitextfield-in-uitableview-ios

我希望这能有所帮助!