facebook return com.facebook.sdk, error = 5 when I post an image to my own wall

Question

I want to share an image with Url, title, caption and message. I am using Facebook connect to do that. After successful facebook login I am using the following code to share the image.

NSLog(@"card image = %@",[MyClass getcardImage]);
// This log gives me an image object like <UIImage: 0x1f32d450>

NSMutableDictionary * params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                nil];
[params setObject:@"An Image" forKey:@"name"];
[params setObject:[MyClass getCardURL] forKey:@"link"];
[params setObject:@"My Image" forKey:@"caption"];
[params setObject:@"Sharing myImage" forKey:@"message"];
[params setObject:UIImagePNGRepresentation([MyClass getcardImage]) forKey:@"picture"];
[params setObject:@"Hey! I am sharing my picture" forKey:@"description"];
[FBRequestConnection
 startWithGraphPath:@"me/feed"
 parameters:params
 HTTPMethod:@"POST"
 completionHandler:^(FBRequestConnection *connection,
                     id result,
                     NSError *error) {
     NSString *alertText;
     if (error) {
         alertText = [NSString stringWithFormat:
                      @"error: domain = %@, code = %d",
                      error.domain, error.code];
     } else {
         alertText = [NSString stringWithFormat:
                      @"Posted action, id: %@",
                      result[@"id"]];
     }

I get error message like error: domain = com.facebook.sdk, code=5

But when I just remove the following line from params dictionary,

 [params setObject:UIImagePNGRepresentation([MyClass getcardImage]) forKey:@"picture"];

The code works well.
Whats wrong in that line.
I want to add image as well.

Answer 1

The "me/feed" endpoint only accepts urls for the "picture" parameter, and not the image data.

See https://developers.facebook.com/docs/reference/api/user/#posts

So you should only include a url to an image, but not the image itself.