read write ios issue in application start

I added text file to the mainbundle and I write line on it to control the opening of my application like this

NSString *fileNa开发者_运维百科me =  [[NSBundle mainBundle] pathForResource:@"TestCases" ofType:@"txt"];

NSString *content = [[NSString alloc] initWithContentsOfFile:fileName
                                                usedEncoding:nil
                                                       error:nil];

if ([content length] == 0 ) {


    [self MoveAndBuild ];

}


content = @"Downloaded";
[content writeToFile:fileName 
          atomically:NO 
            encoding:NSStringEncodingConversionAllowLossy 
               error:nil];

what is supossed is that [self MoveAndBuild ]; be called just one time after installing the application , but it be called every time the application be opened , am I missing something

best regards

Files in your application's bundle are read only. I'd use NSUserDefaults in your case. E.g.

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

Then you can read a value with

BOOL downloaded = [prefs boolForKey:@"downloaded"]

And write with

[prefs setBool:YES forKey:@"downloaded"];

[content writeToFile:fileName atomically:NO encoding:NSStringEncodingConversionAllowLossy error:nil];

will never be successful because fileName points to the app bundle, which is non writable. So you are testing against the same file all the time.

If you would have used proper error handling you would have seen that.

NSError *error;
if (![content writeToFile:fileName atomically:NO encoding:NSStringEncodingConversionAllowLossy error:&error]) {
    NSLog(@"Error writing - %@", error);
}

btw. NSStringEncodingConversionAllowLossy is not a valid encoding