UITextField заменяют текст Поддержкой NSUndoManager

Shake-to-undo
Put this line in your appDelegate's application:didFinishLaunchingWithOptions: method:

    application.applicationSupportsShakeToEdit = YES;

и в соответствующем viewController.m

    -(BOOL)canBecomeFirstResponder {
        return YES;
    }

остальная часть этого кода входит в viewController.m

Property
Put this in the class extension...

    @interface myViewController()
    @property (weak, nonatomic) IBOutlet UITextField *inputTextField;
    @end

свяжите его до своего текстового поля в Интерфейсном Строителе.

Undo method
Adds an invocation of itself to the redo stack

    - (void)undoTextFieldEdit: (NSString*)string
    {
        [self.undoManager registerUndoWithTarget:self
                                        selector:@selector(undoTextFieldEdit:)
                                          object:self.inputTextField.text];
        self.inputTextField.text = string;
    }

(мы не должны создавать случай NSUndoManager, мы наследуем один суперклассу UIResponder),

Undo actions
Not required for shake-to-undo, but could be useful...

    - (IBAction)undo:(id)sender {
        [self.undoManager undo];
    }
    - (IBAction)redo:(id)sender {
        [self.undoManager redo];
    }

Invocations of the undo method
Here are two different examples of changing the textField's contents…

Example 1
Set the textField's contents from a button action

    - (IBAction)addLabelText:(UIButton*)sender {
        [self.undoManager registerUndoWithTarget:self
                                        selector:@selector(undoTextFieldEdit:)
                                          object:self.inputTextField.text];
        self.inputTextField.text = @"text";
    }

Рискуя потерей ясности, мы можем сократить это к:

    - (IBAction)addLabelText:(UIButton*)sender {
        [self undoTextFieldEdit: @"text"];
    }

поскольку undoManager просьба - то же самое в обоих методах

Example 2
Direct keyboard input editing

    #pragma mark - textField delegate methods

    - (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
    {
        [self.undoManager registerUndoWithTarget:self
                                        selector:@selector(undoTextFieldEdit:)
                                          object:textField.text];
        return YES;
    }

    - (BOOL)textFieldShouldReturn:(UITextField *)textField
    {
        //to dismiss the keyboard
        [textField resignFirstResponder];
        return YES;
    }