我无法在iOS中保存和检索图像

我无法在iOS中保存和检索图像。我得到nil图像通过这段代码:

-(NSString *)saveImageDataWithImage:(UIImage *)image
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *photoName = [NSString stringWithFormat:@"%ld.png",
                           (long)[[NSDate date] timeIntervalSince1970]];
    NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:photoName];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if (![fileManager fileExistsAtPath:getImagePath])
    {
        NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(image)];
        [data1 writeToFile:getImagePath atomically:YES];
    }
    return photoName;
}
-(UIImage *)GetImageFromPath:(NSString *)ImageName
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:ImageName];
    UIImage *thumbNail = [[UIImage alloc] initWithContentsOfFile:getImagePath];
    return thumbNail;
}

为什么我得到nil图像?

请帮帮我。