title: How to use method stringWithContentsOfFile:encoding:error
body: <p>I don't know how to use this method. </p>
  
  <p>I want to get the data in an rtf file as a NSString, however I can not.</p>
  
  <p>Here is part of my code.</p>
  
  <pre><code>NSString *filePath = @"path of the file";
  
  NSString *ImagePath = [[[NSString alloc] init] autorelease];
  
  imagePath = [NSString stringWithContentsOfFile: filePath encoding:(NSStringEncoding)nil error:(NSError**) nil];
  </code></pre>
  
  <p>I can't readout the data in that .rtf file. I am appreciate that everyone may help me. Thanks.</p>