iOS问题中的自定义警报视图

在我的应用中，我必须创建一个自定义警报视图，如下所示：

因此，我按照本教程创建了一个自定义警报视图。我完成了，但是在以下方法中遇到了问题：

- (void)addOrRemoveButtonWithTag:(int)tag andActionToPerform:(BOOL)shouldRemove {
    NSMutableArray *items = [[NSMutableArray alloc]init];

    [items addObject:self.buttonOk];
    [items addObject:self.buttonClose];

    int buttonIndex = (tag == 1);

    if (shouldRemove) {
        [items removeObjectAtIndex:buttonIndex];
    } else {
        if (tag == 1) {
            [items insertObject:self.buttonOk atIndex:buttonIndex];
        } else {
            [items insertObject:self.buttonClose atIndex:buttonIndex];
        }
    }
}

我编辑的内容比本教程要多，因为我不需要按钮的UIToolBar。当我运行该应用程序时，它说我不能在NSMutableArray中插入nil对象，但是我不明白出了什么问题，希望您能帮助我解决此问题。

更新这里是我开发的所有类代码：

#import "CustomAlertViewController.h"

#define ANIMATION_DURATION  0.25

@interface CustomAlertViewController ()
- (IBAction)buttonOk:(UIButton *)sender;
- (IBAction)buttonCancel:(UIButton *)sender;
@property (weak, nonatomic) IBOutlet UIButton *buttonClose;
@property (weak, nonatomic) IBOutlet UIButton *buttonOk;

@property (strong, nonatomic) IBOutlet UIView *viewAlert;

-(void)addOrRemoveButtonWithTag:(int)tag andActionToPerform:(BOOL)shouldRemove;

@end

@implementation CustomAlertViewController

- (id)init
{
    self = [super init];
    if (self) {
        [self.viewAlert setFrame:CGRectMake(self.labelAlertView.frame.origin.x,
                                         self.labelAlertView.frame.origin.y,
                                         self.labelAlertView.frame.size.width,
                                         self.viewAlert.frame.size.height)];
        [self.buttonOk setTag:1];
        [self.buttonClose setTag:0];
    }
    return self;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)showCustomAlertInView:(UIView *)targetView withMessage:(NSString *)message {
    CGFloat statusBarOffset;

    if (![[UIApplication sharedApplication] isStatusBarHidden]) {
        CGSize statusBarSize = [[UIApplication sharedApplication] statusBarFrame].size;
        if (statusBarSize.width < statusBarSize.height) {
            statusBarOffset = statusBarSize.width;
        } else {
            statusBarOffset = statusBarSize.height;
        }
    } else {
        statusBarOffset = 0.0;
    }
    CGFloat width, height, offsetX, offsetY;

    if ([[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationLandscapeLeft ||
        [[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationLandscapeRight) {
        width = targetView.frame.size.width;
        height = targetView.frame.size.height;

        offsetX = 0.0;
        offsetY = -statusBarOffset;
    }

    [self.view setFrame:CGRectMake(targetView.frame.origin.x, targetView.frame.origin.y, width, height)];
    [self.view setFrame:CGRectOffset(self.view.frame, offsetX, offsetY)];
    [targetView addSubview:self.view];

    [self.viewAlert setFrame:CGRectMake(0.0, -self.viewAlert.frame.size.height, self.viewAlert.frame.size.width, self.viewAlert.frame.size.height)];

    [UIView beginAnimations:@"" context:nil];
    [UIView setAnimationDuration:ANIMATION_DURATION];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
    [self.viewAlert setFrame:CGRectMake(0.0, 0.0, self.viewAlert.frame.size.width, self.viewAlert.frame.size.height)];
    [UIView commitAnimations];

    [self.labelAlertView setText:@"CIAO"];
}

- (void)removeCustomAlertFromView {
    [UIView beginAnimations:@"" context:nil];
    [UIView setAnimationDuration:ANIMATION_DURATION];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
    [self.viewAlert setFrame:CGRectMake(0.0, -self.viewAlert.frame.size.height, self.viewAlert.frame.size.width, self.viewAlert.frame.size.height)];
    [UIView commitAnimations];

    [self.view performSelector:@selector(removeFromSuperview) withObject:nil afterDelay:ANIMATION_DURATION];
}

- (void)removeCustomAlertFromViewInstantly {
    [self.view removeFromSuperview];
}

- (BOOL)isOkayButtonRemoved {
    if (self.buttonOk == nil) {
        return YES;
    } else {
        return NO;
    }
}

- (BOOL)isCancelButtonRemoved {
    if (self.buttonClose == nil) {
        return YES;
    } else {
        return NO;
    }
}

- (void)removeOkayButton:(BOOL)shouldRemove {
    if ([self isOkayButtonRemoved] != shouldRemove) {
        [self addOrRemoveButtonWithTag:1 andActionToPerform:shouldRemove];
    }
}

- (void)removeCancelButton:(BOOL)shouldRemove {
    if ([self isCancelButtonRemoved] != shouldRemove) {
        [self addOrRemoveButtonWithTag:0 andActionToPerform:shouldRemove];
    }
}

- (void)addOrRemoveButtonWithTag:(int)tag andActionToPerform:(BOOL)shouldRemove {
    NSMutableArray *items = [[NSMutableArray alloc]init];

    [items addObject:self.buttonOk];
    [items addObject:self.buttonClose];

    int buttonIndex = (tag == 1);

    if (shouldRemove) {
        [items removeObjectAtIndex:buttonIndex];
    } else {
        if (tag == 1) {
            [items insertObject:self.buttonOk atIndex:buttonIndex];
        } else {
            [items insertObject:self.buttonClose atIndex:buttonIndex];
        }
    }
}

- (IBAction)buttonOk:(UIButton *)sender {
    [self.delegate customAlertOk];
}

- (IBAction)buttonCancel:(UIButton *)sender {
    [self.delegate customAlertCancel];
}
@end

我使用CustomAlertView的UPDATE 2代码：

#import "PromotionsViewController.h"
#import "CustomAlertViewController.h"

@interface PromotionsViewController () <CustomAlertViewControllerDelegate> {
    BOOL isDeletingItem;
}


@property(nonatomic,strong) CustomAlertViewController *customAlert;

- (IBAction)buttonBack:(UIButton *)sender;
@property (weak, nonatomic) IBOutlet UIButton *buttonAlert;
- (IBAction)buttonAlert:(UIButton *)sender;

@end

@implementation PromotionsViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    [self.buttonAlert setTitle:self.promotionSelected forState:UIControlStateNormal];
    [self.customAlert setDelegate:self];
    isDeletingItem = NO;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)buttonBack:(UIButton *)sender {
    [self dismissViewControllerAnimated:YES completion:nil];
}
- (IBAction)buttonAlert:(UIButton *)sender {
    self.customAlert = [[CustomAlertViewController alloc]init];
    [self.customAlert removeOkayButton:NO];
    [self.customAlert removeCancelButton:NO];
    NSString *message = [NSString stringWithFormat:@"La tua offerta %@ del 20%% è stata convertita in punti IoSi x10", self.promotionSelected];
    [self.customAlert showCustomAlertInView:self.view withMessage:message];
    isDeletingItem = YES;
}

- (void)customAlertOk {
    if (isDeletingItem) {
        [self.customAlert removeCustomAlertFromViewInstantly];
    } else {
        [self.customAlert removeCustomAlertFromView];
    }
}

- (void)customAlertCancel {
    [self.customAlert removeCustomAlertFromView];
    if (isDeletingItem) {
        isDeletingItem = NO;
    }
}

@end