Iphone 按下按钮时如何撤消UITextField？

当我按下按钮时，我正在使用数组创建UITextField。我想添加一个新的按钮，撤销功能。当我按下“撤消”按钮时，我创建的最后一个UITextField将被删除

在我的ViewController.h上

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UITextFieldDelegate>
{

    NSMutableArray *textfieldform;
    UITextField *textField1;
}

@property (nonatomic) NSInteger text1;

@property (nonatomic, retain) NSMutableArray *textfieldform;
@property (nonatomic, readwrite) int yOrigin;
@property (nonatomic, readwrite) int xOrigin;


-(IBAction) textFieldcreating;
-(IBAction) undo;


@end

---

根据文本字段在数组中的位置，为每个文本字段指定一个标记

-(IBAction)textFieldcreating{

UITextField *textField1 = [[UITextField alloc] initWithFrame:CGRectMake(xOrigin, yOrigin, 100, 40)];
textField1.borderStyle = UITextBorderStyleRoundedRect;
textField1.font = [UIFont systemFontOfSize:15];
textField1.placeholder = @"enter text";
textField1.autocorrectionType = UITextAutocorrectionTypeNo;
textField1.keyboardType = UIKeyboardTypeDefault;
textField1.returnKeyType = UIReturnKeyDone;
textField1.clearButtonMode = UITextFieldViewModeWhileEditing;
textField1.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;    
textField1.delegate = self;

textField1.tag = textfieldform.count;

[textfieldform addObject:textField1];
[self.view addSubview:textField1];
yOrigin = yOrigin + 40 + 10; 
xOrigin = xOrigin + 20 + 10; 
//old yorigin + btn height + y offset

}

在你的行动中应该有

-(IBAction)undo{  //Should also check here if you actually have an object at that index path. (for example if there are no text fields created yet)

UITextField *textField = (UITextField *)[self.view viewWithTag:textfieldform.count - 1];
textField = nil;
[textField removeFromSuperview];
[textfieldform removeLastObject];

---

}

因为要将文本字段添加到数组中，所以只需从该数组中获取最后一个对象并将其从superview中删除即可

- (IBAction)undo:(id)sender {
    UITextField *textFieldToRemove = [textfieldform lastObject];
    if (textFieldToRemove) {
        [textfieldform removeObject:textFieldToRemove];
        [textFieldToRemove removeFromSuperview];
    }
}

- (IBAction)undo:(id)sender {
    UITextField *textFieldToRemove = [textfieldform lastObject];
    if (textFieldToRemove) {
        [textfieldform removeObject:textFieldToRemove];
        [textFieldToRemove removeFromSuperview];
    }
}