Question

In my project, I am adding ComboBox, Text, Link label to my DataGridView dgvMain.I have created different methods for different cell templates as shown below: (The code below is working)

gridLnklbl(string headerName)

   DataGridViewLinkColumn col = new DataGridViewLinkColumn();
   col.HeaderText = headerName;     //
   col.Name = "col" + headerName;   // same code repeating to all the methods
   dgvMain.Columns.Add(col);        //

gridCmb(string headerName)

   DataGridViewComboBoxColumn col = new DataGridViewComboBoxColumn();
   col.HeaderText = headerName;
   col.Name = "col" + headerName;
   dgvMain.Columns.Add(col);

gridText(string headerName)

   DataGridViewTextBoxColumn col = new DataGridViewTextBoxColumn();
   col.HeaderText = headerName;
   col.Name = "col" + headerName;
   dgvMain.Columns.Add(col);  

As you can see, except the declaration of objects, the code for every method is repeating. Just curious to know, can the repeating code be converted to single method? I dont know how to do that.. Its not about 3 codes of line, I have written many more lines which can be make common to those methods.

Answer 1

I would use a generic Extension Method on DataGridView:

public static class ExtensionMethods {

    public static void AddColumn<TCol>(this DataGridView dgv, string headerName) 
        where TCol : DataGridViewColumn, new()
    {
       var col = new TCol {
           HeaderText = headerName,
           Name = "col" + headerName,
       };
       dgv.Columns.Add(col); 
    }
}

There is a constraint on TCol that ensures it is a subclass of DataGridViewColumn.

Invoke the extension method as such:

dgvMain.AddColumn<DataGridViewLinkColumn>(headerName);