title: iPhone - Draw white text on black view using CGContext
body: <p>I can't achieve drawing some white text on a black view using CGContext in a drawRect method.</p>
  
  <p>I do :</p>
  
  <pre><code>CGContextRef context = UIGraphicsGetCurrentContext();
  
  CGContextSetStrokeColorWithColor(context, [UIColor whiteColor].CGColor);
  CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
  CGContextSetLineWidth(context, 1.0);
  CGContextSelectFont(context, "Helvetica", 20, kCGEncodingMacRoman);
  CGContextSetTextDrawingMode(context, kCGTextFill);
  
  CGPoint center = self.center;
  </code></pre>
  
  <p>And then...<br>
  Impossible to find the correct method.<br>
  I've tried this :</p>
  
  <pre><code>UIFont* font = [UIFont fontWithName:@"Geneva" size:12.0];
  [@"Some text" drawAtPoint:center withFont:font];
  </code></pre>
  
  <p>But it does not work.</p>
  
  <p>I don't find any CGContext method for that. Where is it hidden ?</p>
  
  <p>How may I draw that text in white ?</p>