Ios 将NSString添加到NSMutableArray崩溃

在我的iOS应用程序上，我有一个包含两件事的UI：一个选择器视图和一个按钮

我使用NSMutableArray初始化我的选择器视图，如下所示：

@interface ViewController ()
{
    NSMutableArray *_pickerDataCategory;
}
- (void)viewDidLoad
{
   // Initialize Data
    _pickerDataCategory = [[NSMutableArray alloc] init];

    NSMutableArray  *array = [NSMutableArray arrayWithObjects:
                            @"cat1", @"cat2", @"cat3", @"cat4", nil ];

    _pickerDataCategory = array;

 //First I had initialize like this :  NSMutableArray  *_pickerDataCategory = [NSMutableArray arrayWithObjects:
                            @"cat1", @"cat2", @"cat3", @"cat4", nil ];
}

然后，我有一个按钮，显示一个弹出窗口，用户可以在那里写东西。此方法的目的是将新的NSString对象添加到我的NSMutableArray

   - (IBAction)addNewCategory:(id)sender {
        __block bool isNotExist = false;
           UIAlertController * alertController = [UIAlertController alertControllerWithTitle: @"Add new category"
                                                                                  message: @"Please write a new category"
                                                                           preferredStyle:UIAlertControllerStyleAlert];
        [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
            textField.placeholder = @"Category";
            textField.textColor = [UIColor blueColor];
            textField.clearButtonMode = UITextFieldViewModeWhileEditing;
            textField.borderStyle = UITextBorderStyleRoundedRect;
        }];
    UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        [alertController dismissViewControllerAnimated:YES completion:nil];
    }];

    UIAlertAction *ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        NSString *input = alertController.textFields[0].text;
        //Check if the category exist already

        for (NSString *category in _pickerDataCategory)
        {
            if ([category isEqualToString:input])
            {
                 [self popupMessage:@"Category already exists" title:@"Error"];
                isNotExist = false;
                return;
            }else{
                NSString *msg = [@"Category has been added : " stringByAppendingString:input];
                 [self popupMessage:msg title:@"Ok"];
                isNotExist = true;


                //[_pickerDataCategory addObject:input];//CRASH
              //  [_picker_cateogry reloadAllComponents];

            }
        }



    }];

    [alertController addAction:cancel];
    [alertController addAction:ok];

    [self presentViewController:alertController animated:YES completion:nil];

}

但当我想将Textfield输入添加到NSMutableArray时，它崩溃了。我真的不明白为什么。我在初始化NSMutableArray时很小心。我在互联网上查找了关于它的任何信息，我找到的两个信息要么是关于初始化的信息，要么是关于它是可变数组而不是简单数组的信息

此外，我不明白为什么我要在

[self-presentViewController:alertController animated:YES completion:nil]之后添加一些代码，它不会被执行。。。我也没有找到关于它的任何信息

你能帮我弄清楚它为什么会坏掉而不能工作吗？
感谢
就您的崩溃而言，这可能与您在枚举数组时试图修改数组有关。我会把它们分成两个独立的任务

类似于

NSMutableArray *additionalObjects = [[NSMutableArray alloc] init];

for (NSString *category in _pickerDataCategory) {
    if (![category isEqualToString:input]) {
        [additionalObjects addObject: category];
    }
}

[_pickerDataCategory addObjectsFromArray: additionalObjects];

问题是，您试图在迭代时向数组中添加值，将数据保存在其他数组中，然后将其添加到_pickerDataCategory中。代码如下：-枚举时

    - (IBAction)addNewCategory:(id)sender {
    __block bool isNotExist = false;
       UIAlertController * alertController = [UIAlertController alertControllerWithTitle: @"Add new category"
                                                                              message: @"Please write a new category"
                                                                       preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.placeholder = @"Category";
        textField.textColor = [UIColor blueColor];
        textField.clearButtonMode = UITextFieldViewModeWhileEditing;
        textField.borderStyle = UITextBorderStyleRoundedRect;
    }];
UIAlertAction *cancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
    [alertController dismissViewControllerAnimated:YES completion:nil];
}];

UIAlertAction *ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
    NSString *input = alertController.textFields[0].text;
    //Check if the category exist already
    NSMutableArray * arrTemp = _pickerDataCategory;
    for (NSString *category in arrTemp)
    {
        if ([category isEqualToString:input])
        {
             [self popupMessage:@"Category already exists" title:@"Error"];
            isNotExist = false;
            return;
        }else{
            NSString *msg = [@"Category has been added : " stringByAppendingString:input];
             [self popupMessage:msg title:@"Ok"];
            isNotExist = true;


            [_pickerDataCategory addObject:input];//CRASH
            [_picker_cateogry reloadAllComponents];

        }
    }



}];

[alertController addAction:cancel];
[alertController addAction:ok];

[self presentViewController:alertController animated:YES completion:nil];

  }

你能把你收到的紧急消息也加上吗？将使查找问题更容易一些！：）@瑞克，是的，我忘了。我只是编辑我的帖子；）感谢在试图将对象添加到数组中的位置放置一个断点，并检查值是否为nil。实际上，即使我写入[\u pickerDataCategory addObject:@“Test”]，它也会崩溃……因此我认为这不是值为nil。不，不是。我刚检查过。如果它是零，它会显示一条错误消息，而我什么也没有得到…很好的观察MaratThank！我只是试着像你说的那样分两次做。一旦用户写了一些东西，就会存储NSString，然后在循环之后，我将其添加到NSMutableArray中。你知道为什么吗，如果我在presentViewController后面放了一些代码，它就不会执行了？只需将枚举数组替换为temp即可