title: Winform Combobox item which starts with "C" will be selected once you double click any place
body: <p>As the title, it is a strange issue. When I add some items to the combobox as below and set its style to DropDownList:</p>
  
  <pre><code>        this.comboBox1.Items.Add("a");
          this.comboBox1.Items.Add("b");
          this.comboBox1.Items.Add("c");
          this.comboBox1.Items.Add("d");
          this.comboBox1.Items.Add("e");
          this.comboBox1.DropDownStyle=ComboBoxStyle.DropDownList;
  </code></pre>
  
  <p>When you run the windows form application and double click any blank area in the form around this combobox (do not double click on combobox), the selection will automatically become to c as below:</p>
  
  <p><a href="https://i.stack.imgur.com/qKsBB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qKsBB.png" alt="combobox start with &quot;c&quot;"></a></p>
  
  <p>Is that a magic character in the combobox? It drove me crazy! Is there anyone could help me? </p>
  
  <p>Thanks,</p>