Ios 从服务器获取图像并保存到Documents文件夹

我将图像作为NSData保存到Documents文件夹

问题是，当我尝试将其保存到Documents文件夹时，它会保存四分之二或四分之三。它随机保存

我不知道问题出在哪里，因为在第一次保存失败后，第二次尝试可能会成功保存特定的图像

你能帮帮我吗

 NSData * response = [appDel.serviceHelper serviceCall:@"" withURL:[NSString stringWithFormat:@"%@/Application/GetImage/%@",appDel.appPage.editorServiceURL,ID]];

 NSError *error = nil;
 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentsDirectory = [paths objectAtIndex:0]; // Get documents folder
 NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:@"/Images"];


if(response !=nil)
{
    if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
    {
        [[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error];
    }

    UIImage *image = [[UIImage alloc] initWithData:response];

    NSString *pngFilePath = [NSString stringWithFormat:@"%@/%@",dataPath,[NSString stringWithFormat:@"%@",fileName]];

    NSData *data1;
    if([pngFilePath rangeOfString:@".png"].location !=NSNotFound)
    {
        data1 = [NSData dataWithData:UIImagePNGRepresentation(image)];
        NSLog(@"png Image");

    }
    else if([pngFilePath rangeOfString:@".jpg"].location !=NSNotFound)
    {
        data1 = [NSData dataWithData:UIImageJPEGRepresentation(image,1.0)];
        NSLog(@"jpg Image");

    }
    else
    {
        NSLog(@"another extension Image");

    }


    [data1 writeToFile:pngFilePath atomically:YES];

    //[appDel.fileHelper writeToFile:response withFileName:fileName];
}

---

尝试将响应作为NSMutableDictionary而不是NSData。这可能会告诉您异常是什么。

我想您需要添加正在使用的代码，否则很难看出问题出在哪里。@MarkGibson我已经添加了代码

 #define   DocumentsPath                 [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]

 NSURLSession *defaultNSURLSession ;

 CallMethod:   

 [self downloadImage_WithImageName:@"HERE YOUR FILENAME" FromFileURL:@"HERE IMAGE URL"];

-(void) downloadImage_WithImageName:(NSString *)imageName FromFileURL:(NSString *)fileURL{


 NSString *dataPath = [DocumentsPath stringByAppendingPathComponent:@"/Images"];
 NSString *filePath=[[NSString alloc] initWithFormat:@"%@/Images/%@",DocumentsPath,imageName];

if (![[NSFileManager defaultManager] fileExistsAtPath:filePath])
{
    //NSLog(@"Downloading %@ to %@...", fileURL, filePath);


    NSURLRequest *request=[[NSURLRequest alloc] initWithURL:[NSURL URLWithString:fileURL]];
    NSURLSessionDownloadTask *downTask = [defaultNSURLSession downloadTaskWithRequest:request completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
        if (!error) {
            if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
                [[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error]; //Create folder

            NSError *err = nil;

            if ([[NSFileManager defaultManager] moveItemAtURL:location toURL:[NSURL fileURLWithPath:filePath] error:&err]) {
               //Reload your UITableview or UICollectionView
            }else{
                NSLog(@"move error %@", error);
            }

        }else{
            NSLog(@"error %@",error);
        }

    }];
    [downTask resume];

} else {
    NSLog(@"%@ already exists. not downloading.", imageName);
}

}