iOS往沙盒文件夹plist里存多种格式数据,不被覆盖

iOS往沙盒文件夹plist里存多种格式数据,不被覆盖的方法(原理是大字典里边装键和值,键为字符串,值符合存储规定的都可以存,不可以的处理一下也可以存)

 //sandBox
+ (id)readDataWithKey:(NSString *)key plistFileName:(NSString *)fileName
{
//    NSString * plistPath = [NSHomeDirectory() stringByAppendingFormat:@"/Library/File_Plist/%@",fileName];
    NSString * filePath = [NSHomeDirectory() stringByAppendingFormat:@"%@%@",kPlistFilePath,fileName];
    NSMutableDictionary  *mdict = [NSMutableDictionary dictionaryWithContentsOfFile:filePath];
    id obj = mdict[key];
    return obj;
}

+ (BOOL)writeData:(id)data plistKey:(NSString *)plistKey plistFileName:(NSString *)fileName{
//    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
//    DDLog(@"%@", paths[0]);

//    NSString * plistPath = [NSHomeDirectory() stringByAppendingFormat:@"/Library/File_Plist/%@",fileName];
      NSString * plistPath = [NSHomeDirectory() stringByAppendingFormat:@"%@",kPlistFilePath];
    if (![Utilities_DigitalMedia fileExistAtPath:plistPath]) {
        [Utilities_DigitalMedia createDirectoryAtPath:plistPath];
    }
    NSString *filePath = [plistPath stringByAppendingPathComponent:kPlistName_common];
    DDLog(@"%@\n", filePath);

    NSMutableDictionary  *mdict = [NSMutableDictionary dictionaryWithCapacity:0];
    if ([Utilities_DigitalMedia fileExistAtPath:plistPath]) {
        mdict = [NSMutableDictionary dictionaryWithContentsOfFile:filePath];
        if (!mdict) {
            mdict = [NSMutableDictionary dictionaryWithCapacity:0];

        }
    }

    [mdict setSafeObjct:data forKey:plistKey];

    BOOL isSuccess = [mdict writeToFile:filePath atomically:YES];
    if (isSuccess) {
        DDLog(@"isSuccess");
    }else{
        DDLog(@"isFail");
    }
    return nil;
}