ios - 从解析中删除照片

Question

我想从解析中删除照片。我该怎么办？看似一件容易的事，但我做不到，也没有真正的资料显示如何做。这是我的保存代码。我正在保存一个名为Topc的 class 。

- (void)uploadImage:(NSData *)imageData
{
    PFFile *imageFile = [PFFile fileWithName:@"TopsImage.jpg" data:imageData];

    HUD = [[MBProgressHUD alloc] initWithView:self.view];
    [self.view addSubview:HUD];

    // Set determinate mode
    HUD.mode = MBProgressHUDModeDeterminate;
    HUD.delegate = self;
    HUD.labelText = @"Uploading";
    [HUD show:YES];

    // Save PFFile
    [imageFile saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
        if (!error) {
            //Hide determinate HUD
            [HUD hide:YES];

            // Show checkmark
            HUD = [[MBProgressHUD alloc] initWithView:self.view];
            [self.view addSubview:HUD];

            // The sample image is based on the work by http://www.pixelpressicons.com, http://creativecommons.org/licenses/by/2.5/ca/
            // Make the customViews 37 by 37 pixels for best results (those are the bounds of the build-in progress indicators)
            HUD.customView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.png"]];

            // Set custom view mode
            HUD.mode = MBProgressHUDModeCustomView;

            HUD.delegate = self;

            // Create a PFObject around a PFFile and associate it with the current user
            PFObject *userPhoto = [PFObject objectWithClassName:@"Topc"];
            [userPhoto setObject:imageFile forKey:@"imageFile"];

            // Set the access control list to current user for security purposes
            userPhoto.ACL = [PFACL ACLWithUser:[PFUser currentUser]];

            PFUser *user = [PFUser currentUser];
            [userPhoto setObject:user forKey:@"user"];

            [userPhoto saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                if (!error) {
                    [self refresh:nil];
                }
                else{
                    // Log details of the failure
                    NSLog(@"Error: %@ %@", error, [error userInfo]);
                }
            }];
        }
        else{
            [HUD hide:YES];
            // Log details of the failure
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
    } progressBlock:^(int percentDone) {
        // Update your progress spinner here. percentDone will be between 0 and 100.
        HUD.progress = (float)percentDone/100;
    }];
}

Answer 1

我在PFFile上写了一个类别，该类别允许您更新文件，这意味着删除旧文件，然后上传具有相同名称的新文件。我本来以为替换关联对象中的文件会删除旧的文件，但是并没有这样做，因为我的数据使用率正在增加。

+(void)updateFileWithName:(NSString*)name data:(NSData*)imageData completion:(void(^)(PFFile* file))completion
{
NSString* endpoint = [NSString stringWithFormat: @"https://api.parse.com/1/files/%@", name];
NSURL* url = [NSURL URLWithString:endpoint];
NSMutableURLRequest* req = [NSMutableURLRequest requestWithURL:url];

[req setHTTPMethod:@"DELETE"];
[req setValue:kParseApplicationKey forHTTPHeaderField:@"X-Parse-Application-Id"];
[req setValue:kParseMasterKey forHTTPHeaderField:@"X-Parse-Master-Key"];

NSLog(@"Updating file: %@", name);
[NSURLConnection sendAsynchronousRequest:req
                                   queue:[NSOperationQueue currentQueue]
                       completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
                           NSLog(@"Deleted old file");
                           PFFile* file = [PFFile fileWithName:name data:imageData];
                           [file saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
                               NSLog(@"Saved new file");
                               completion(file);
                           }];

                       }];
}

您可以轻松地将其更改为通过删除 NSURLConnection完成处理程序中的块来仅删除文件