Parse.com-从.txt检索文本

Question

I'm trying to retrieve some text from a file that I uploaded to Parse, but anything that I try seems not to work. I tried using the example that Parse gave, but I couldn't make it work. Can somebody help or explain to me how I can do that?

This is the example:

PFFile *applicantResume = anotherApplication[@"applicantResumeFile"]; 
NSData *resumeData = [applicantResume getData];

Thanks

Answer 1

You need to convert the data back to a string, try this.

Save

PFObject * anotherApplication = [[PFObject alloc] initWithClassName:@"Resumes"];
NSData *data = [@"Working at Parse is great!" dataUsingEncoding:NSUTF8StringEncoding];
PFFile *file = [PFFile fileWithName:@"resume.txt" data:data];
anotherApplication[@"applicantResumeFile"] = file;
[anotherApplication save];

Open

[anotherApplication fetchIfNeeded];
PFFile *applicantResume = anotherApplication[@"applicantResumeFile"];
NSData *resumeData = [applicantResume getData];
NSString* dataStr = [[NSString alloc] initWithData:resumeData encoding:NSUTF8StringEncoding];
NSLog(@"Received string: %@", dataStr);

Don't forget that in practice, it's best to use 'getDataInBackgroundWithBlock:' , 'saveInBackgroundWithBlock:' , and 'fetchIfNeededInBackgroundWithBlock:'

A note on blocks:

NSLog(@"Will Run 1st: %@", reflex.description); // will be null
[applicantResume getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
    NSString* dataStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    reflex.description = dataStr;
    NSLog(@"Will Run 3rd: %@", reflex.description); // will contain string.
}];
NSLog(@"Will Run 2nd: %@", reflex.description); // will be null

Answer 2

PFFile *applicantResume = object[@"applicantResumeFile"];
NSData *resumeData = [applicantResume getData];
NSString* dataStr = [[NSString alloc] initWithData:resumeData encoding:NSUTF8StringEncoding];
reflex.description = dataStr; 

It workы

When I use getData it doesnt

PFFile *applicantResume = object[@"applicantResumeFile"];
[applicantResume getDataInBackgroundWithBlock:^(NSData *data, NSError *error) {
    if (!error) {
        NSString* dataStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        reflex.description = dataStr;

    }
}];