Question

请帮助我。从数组中删除对象时，我就卡在这里。

for (id obj in self.arrSavedImage)
        {
            Class cls = [obj class];

            id newObj = [[cls alloc] init];
            //UIImage *img = nil;
            if([newObj isKindOfClass:[UIImage class]]){

                NSLog(@"class type %@", [newObj class]);
            }
            else{

                [self.arrSavedImage removeObject:obj];
            }

        }

谢谢。

Answer 1

您不应从正在枚举的数组中删除对象。更好的方法是保留要删除的对象列表，然后在枚举完原始数组后删除它们：

NSMutableArray *toDelete = [NSMutableArray new];
for (id obj in self.arrSavedImage)
{
    Class cls = [obj class];
    id newObj = [[cls alloc] init];
    if([newObj isKindOfClass:[UIImage class]]){
        NSLog(@"class type %@", [newObj class]);
    }
    else{
       [toDelete addObject:obj];
    }
}

for (id obj in toDelete)
    [self.arrSavedImage removeObject:obj];

Answer 2

NSMutableArray *itemsToDelete = [[NSMutableArray alloc] init];
for (id obj in self.arrSavedImage)
    {
        Class cls = [obj class];

        id newObj = [[cls alloc] init];
        //UIImage *img = nil;
        if([newObj isKindOfClass:[UIImage class]]){

            NSLog(@"class type %@", [newObj class]);
        }
        else{

            [itemsToDelete addObject:obj];
        }

    }

[self.arrSavedImage removeObjectsInArray:itemsToDelete];

Answer 3

在循环中无法删除数组中的对象。

您应该使用现有数组创建一个新数组并从中删除对象。然后用editedArray替换旧数组。

NSMutableArray * editedArray = [[NSMutableArray alloc] initWithArray:self.arrSavedImage];

for (id obj in self.arrSavedImage)
        {
            Class cls = [obj class];

            id newObj = [[cls alloc] init];
            //UIImage *img = nil;
            if([newObj isKindOfClass:[UIImage class]]){

                NSLog(@"class type %@", [newObj class]);
            }
            else{

                [editedArray removeObject:obj];
            }

        }

[self.arrSavedImage setArray:editedArray];

editedArray = nil;

如何从for循环中删除数组对象

3 个答案: