title: update combobox from another form in c#
body: <p>I want to update combobox of the main form from another form
  this is my main form combobox update code which is in the form_load</p>
  
  <pre><code>public void main_Load(object sender, EventArgs e)
  {
      try
      {
          OleDbDataAdapter db = new OleDbDataAdapter("select * from category", con);
          ds_cmbGroup.Clear();
          cmbGroup.DataSource = null;
          db.Fill(ds_cmbGroup, "t1");
          cmbGroup.DisplayMember = "catname";
          cmbGroup.ValueMember = "catcode";
          cmbGroup.DataSource = ds_cmbGroup.Tables["t1"];
      }
      catch (Exception ex)
      {
      }
  }
  </code></pre>
  
  <p>as I call this method in its own form it runs correctly. this is the code to call it:</p>
  
  <pre><code>main_Load(this, null);
  </code></pre>
  
  <p>but when I call it from another form, (though the dataset updates with no problem) it doesn't change the combobox(cmbGroup) content
  this is the code to load main_Load method from second form:</p>
  
  <pre><code>main Main = new main();
  Main.main_Load(this, null);
  </code></pre>
  
  <p>Thanks in Advance</p>