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)
        }
    }

没有usings标签，也没有为nextField/nextTextField添加属性，你可以尝试模拟TAB，其中"testInput"是你当前的活动字段:

if ([textInput isFirstResponder])
    [textInput.superview.subviews enumerateObjectsAtIndexes:
     [NSIndexSet indexSetWithIndexesInRange:
      NSMakeRange([textInput.superview.subviews indexOfObject:textInput]+1,
                  [textInput.superview.subviews count]-[textInput.superview.subviews indexOfObject:textInput]-1)]
                                                    options:0 usingBlock:^(UIView *obj, NSUInteger idx, BOOL *stop) {
                                                        *stop = !obj.hidden && [obj becomeFirstResponder];
                                                    }];
if ([textInput isFirstResponder])
    [textInput.superview.subviews enumerateObjectsAtIndexes:
     [NSIndexSet indexSetWithIndexesInRange:
      NSMakeRange(0,
                  [textInput.superview.subviews indexOfObject:textInput])]
                                                    options:0 usingBlock:^(UIView *obj, NSUInteger idx, BOOL *stop) {
                                                        *stop = !obj.hidden && [obj becomeFirstResponder];
                                                    }];

我尝试了很多代码，最后，这在Swift 3.0最新版[2017年3月]对我有效

ViewController类应该继承UITextFieldDelegate以使这段代码正常工作。

class ViewController: UIViewController,UITextFieldDelegate  

使用适当的标记号添加文本字段，该标记号用于根据分配给它的增量标记号将控件转移到适当的文本字段。

override func viewDidLoad() {
    userNameTextField.delegate = self
    userNameTextField.tag = 0
    userNameTextField.returnKeyType = UIReturnKeyType.next
    passwordTextField.delegate = self
    passwordTextField.tag = 1
    passwordTextField.returnKeyType = UIReturnKeyType.go
}

在上面的代码中，returnKeyType = UIReturnKeyType。下一个将使键垫返回键显示为下一个你也有其他选项加入/走等，根据你的应用程序改变值。

这个textFieldShouldReturn是一个UITextFieldDelegate控制的方法，在这里我们有下一个字段选择基于标签值的增量

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    if let nextField = textField.superview?.viewWithTag(textField.tag + 1) as? UITextField {
        nextField.becomeFirstResponder()
    } else {
        textField.resignFirstResponder()
        return true;
    }
    return false
 }

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
}

在textFieldShouldReturn你应该检查你目前的文本域不是最后一个，当他们点击下一步，如果不是不要解散键盘..

下面是一个在UIControl上使用类别的选项卡实现。这个解决方案具有Michael和Anth0方法的所有优点，但适用于所有uicontrol，而不仅仅是UITextFields。它还可以与接口生成器和故事板无缝工作。

源代码和示例应用程序:UIControlsWithTabbing的GitHub仓库

用法:

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField transferFirstResponderToNextControl];
    return NO;
}

标题:

//
// UIControl+NextControl.h
// UIControlsWithTabbing
//

#import <UIKit/UIKit.h>

@interface UIControl (NextControl)

@property (nonatomic, weak) IBOutlet UIControl *nextControl;

- (BOOL)transferFirstResponderToNextControl;

@end

实现:

#import "UIControl+NextControl.h"
#import <objc/runtime.h>

static char defaultHashKey;

@implementation UIControl (NextControl)

- (UIControl *)nextControl
{
    return objc_getAssociatedObject(self, &defaultHashKey);
}

- (void)setNextControl:(UIControl *)nextControl
{
    objc_setAssociatedObject(self, &defaultHashKey, nextControl, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (BOOL)transferFirstResponderToNextControl
{
    if (self.nextControl)
    {
        [self.nextControl becomeFirstResponder];

        return YES;
    }

    [self resignFirstResponder];

    return NO;
}

@end