Question

How to add the checkbox field in gridview programatically, what’s wrong with my code?

try
{
  string Data_source=@"Data Source=A-63A9D4D7E7834\SECOND;";
  string Initial_Catalog=@"Initial Catalog=replicate;";
  string User=@"User ID=sa;";
  string Password=@"Password=two";
  string full_con=Data_source+Initial_Catalog+User+Password;
  SqlConnection connection = new SqlConnection(full_con);
  connection.Open();
  SqlCommand numberofrecords = new SqlCommand("SELECT COUNT(*) FROM dbo.Table_1", connection);
  DataSet ds2 = new DataSet();
  SqlDataAdapter testadaptor = new SqlDataAdapter();
  testadaptor.SelectCommand = new SqlCommand("SELECT COUNT(*) FROM dbo.Table_1", connection);
  testadaptor.Fill(ds2);
  grid1.DataSource = ds2;
  CheckBoxField c = new CheckBoxField();
  grid1.Columns.Add(c);
  grid1.DataBind();
  numberofrecords.Dispose();
  connection.Close();
  connection.Dispose();
}
catch (Exception a)
{
  Response.Write("Please check  ");
   Response.Write(a.Message.ToString());
   Response.Write(a.Source.ToString());
}//catch

Answer 1

The CheckBoxField will probably want a value for the DataField property. This should match the column names or aliases in your query. (I don’t think a checkbox will work with number results, though.)

Edited: didn’t realize what you were trying to do. A template field and a regular checkbox should get you closer to what you want. Something like this?

e.g.

const int ColumnSelect = 0;

protected void Page_Load(object sender, EventArgs e)
{       
    //Get real data here.
    DataTable dt = new DataTable();
    dt.Columns.Add("count");                
    dt.Rows.Add(dt.NewRow());
    dt.Rows[0][0] = "5";

    GridView1.Columns.Add(new TemplateField());        
    BoundField b = new BoundField();
    GridView1.Columns.Add(b);
    b.DataField = "count";
    GridView1.DataSource = dt;
    GridView1.DataBind();
}


protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType != DataControlRowType.Header)
    {            
        e.Row.Cells[ColumnSelect].Controls.Add(new CheckBox());
    }
}

Edit #2: as for getting the value, you can certainly do this. Are you looking for a Javascript or server-side solution? Here’s a simple example for server-side if you had a button click:

protected void Button1_Click(object sender, EventArgs e)
{
    foreach(GridViewRow row in GridView1.Rows)
    {
        //Could also use (CheckBox)row.Cells[ColumnSelect].FindControl if you give the checkboxes IDs when generating them.
        CheckBox cb = (CheckBox)row.Cells[ColumnSelect].Controls[0];

        if (cb.Checked)
        {
            //Do something here.
        }
    }
}