如何从parse.com检索图像

Question

Hi i am new to using parse.com Actually iam trying to save image in parse.com and retriving it.. But i successfully saved image as a PFFile

in parse.com dashboard it showing like this

Now how can i retrive image and show in UIImageView

I tryied like this but its not working..

 PFQuery *query = [PFQuery queryWithClassName:@"UserPhoto"];
    [query whereKey:@"userName" containsString:@"ravi"];
    [query getObjectInBackgroundWithId:@"ID" block:^(PFObject *object, NSError *error) {
        if(!error){
            PFFile *im = [object objectForKey:@"imageFile"];
            _getImg.image = im;
        }}];

Here i want to retrive the particular image of userName ravi

Answer 1

To retrieve the image, you need to:

1. Query for the PFObject in question
2. Use -[PFFile getDataInBackgroundWithBlock:] to retrieve the PFFile 's data

3. Create a UIImage with the resulting NSData

    PFQuery *query = [PFQuery queryWithClassName:@"UserPhoto"]; [query whereKey:@"userName" containsString:@"ravi"]; [query getFirstObjectInBackgroundWithBlock:^(PFObject *object, NSError *error) { if (!object) { return NSLog(@"%@", error); } PFFile *imageFile = object[@"imageFile"]; [imageFile getDataInBackgroundWithBlock:^(NSData *data, NSError *error) { if (!data) { return NSLog(@"%@", error); } // Do something with the image self.imageView.image = [UIImage imageWithData:data]; }]; }]; 

As an aside, unless purely for experimentation, or you're performing some operation off of the main thread, I would avoid saving the PFObject synchronously using -[PFObject save] and use instead, the asynchronous version, -[PFObject saveInBackgroundWithBlock:] .

Answer 2

You cannot use getObjectInBackgroundWithId: method in your case. Instead you can use getFirstObjectInBackgroundWithBlock: method to retrieve the first instance.