title: C# VS2010 - Why am I getting the message "An object reference is required for the non-static field"?
body: <p>I've boiled this problem down to a very simple program:</p>
  
  <pre><code>public Form1()
  {
      InitializeComponent();
  
      TextBox tb1;
  
      tb1 = textBox1;             // this line is OK
      tb1 = this.textBox1;        // this line is OK
      tb1 = Form1.textBox1;       // this line generates error message    
  
      }
  </code></pre>
  
  <p>If you mouse over 'textBox1', 'this.textBox1', and 'Form1.textBox1', the tool tip says "TextBox Form1.textBox1" in all cases.</p>
  
  <p>(see www.firish.com/tb1.jpg and www.firish.com/tb2.jpg for screen dumps showing tool tips)</p>
  
  <p>I passed this around the office a bit but no one here could really explain why the 3rd example doesn't compile but didn't get much other than 'uh-huh', 'hmm...' and a couple of shrugs.</p>