title: GraphicsDevice is null in my XNA Windows Game project
body: <p>I have just started trying to make a simple game with XNA 3.1 to help myself learn C# and XNA. I have run into a bit of an interesting problem, however.  In all of the tutorials, one is supposed to pass GraphicsDevice when instantiating a new spriteBatch object like this:</p>
  
  <pre><code>spriteBatch = new SpriteBatch(GraphicsDevice);
  </code></pre>
  
  <p>One might even do this:</p>
  
  <pre><code>GraphicsDevice objGraphics = new graphics.GraphicsDevice;
  spriteBatch = new SpriteBatch(objGraphics);
  </code></pre>
  
  <p>where graphics is the GraphicsDeviceManager.  However, no matter which version I try, I always get an ArgumentNullException when I try to pass the GraphicsDevice object to spriteBatch's constructor.  Almost every tutorial I have found gives the first one and only one mentioned the second option.  Has anyone else run into a similar error or know what could be causing this? I am working in Windows 7 x64 with Visual Studio 2008.</p>
  
  <p>EDIT:</p>
  
  <p>I seem to have found the problem. I was trying to execute that code in the constructor (which is where I assumed it was supposed to go).  I did a bit of Googling and found the answer <a href="http://www.zuneboards.com/forums/flame-board/30344-unhandled-exception-type-system-argumentnullexception-occurred-microsoft-x.html" rel="nofollow noreferrer">here</a>.  Thanks for the help.</p>