C#: How to let Click event by calling from somewhere else?

Question

Let us say, I have below code in one child form, but other forms have same combobox, and they need the same code. So how can I write something in class, and how to call it in comboBoxCountry_Click.

Let us say, I would like to write something GenerateDropdownListForCountry in GlobalCombo.cs, then calling GlobalCombo.GenerateDropdownListForCountry

How to write the syntax?

Or how to call a button_click in another form?

Thanks.

   private void comboBoxCountry_Click(object sender, EventArgs e)
          {
              comboBoxCountry.Items.Clear();

              OdbcConnection Cn = new OdbcConnection(GlobalVariables.DatabaseConnectionString);
              Cn.Open();

              string qCountry = "SELECT DISTINCT Country from Place";

              using (var cmd = new OdbcCommand(qCountry, Cn))
              {
                  using (var reader = cmd.ExecuteReader())
                  {
                      while (reader.Read())
                      {
                          string sColString = reader.GetString(0);
                          comboBoxCountry.Items.Add(sColString);
                      }
                  }
              }

              Cn.Close();


          }

Answer 1

Hi VAer,

>how to call a button_click in another form?

You can set the click event from private to public

    public void comboBoxCountry_Click(object sender, EventArgs e)  
           {  
                     .......  
           }  

Then you could call it in another form:

Note:

But it may cause other problems, I suggest you create a public class for your shared methods.

Best Regards, Dylan

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Answer 2

Thanks. I am actually dealing more validating textbox input character, and it has messagebox. It seems messagebox is not allowed in class.

Anyway, for your code example, can Form2 comboBox1_Click still work if Form1 is closed?

Thanks.