无法从 NSUserDefaults 检索 NSMutableArray [英] Unable to retrieve NSMutableArray from NSUserDefaults

问题描述

我在本地存储中为包含 NSString 列表的 NSMutableArray 保留数据时遇到问题.当应用程序运行时，我有一个 save 方法和一个 get 方法似乎都可以工作.但是，一旦我关闭应用程序并重新启动数组中的项目就消失了.

I have an issue persisting data in local storage for an NSMutableArray containing a list of NSStrings. I have a save method and a get method both appear to work when the app is running. However, once I close the app and restart the items in the array are gone.

NSMutableArray*ImageTags;

获取数据

-(NSMutableArray*)GetDataNSMutableArray:(NSString*)ItemName
{
    NSMutableArray *GetData = [[NSMutableArray alloc] init];
    NSUserDefaults *currentDefaults = [NSUserDefaults standardUserDefaults];
    NSData *dataRepresentingSavedArray = [currentDefaults objectForKey:ItemName];
    if (dataRepresentingSavedArray != nil)
    {
        NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
        if (oldSavedArray != nil)
            GetData = [[NSMutableArray alloc] initWithArray:oldSavedArray];
        else
            GetData = [[NSMutableArray alloc] init];
    }
    return GetData;
}

保存数据

-(void)SaveDataNSMutableArray:(NSString*)ItemName:(NSMutableArray*)Data
{
    [[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:Data] forKey:ItemName];

}

如何添加项目

[ImageTags addObject:Control.titleLabel.text]

数组是如何保存的

[super SaveDataNSMutableArray:CVC_ImageURL:ImageTags];

如何检索数组

ImageTags = [super GetDataNSMutableArray:CVC_ImageURL];

推荐答案

您无法将可变数组存储到用户默认值.存储不可变副本并检索它并转换为可变副本以便在下次启动时访问.

Your can not store mutable array to user defaults. Store the immutable copy and retrieve that and convert to mutable ones to access during the next launch.

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