Run time error 'Cannot find column 0'

Run time error Cannot find column 0. be开发者_开发百科low is my code

string connectiostring = (string)ConfigurationSettings.AppSettings["NorthwindConnectionString"];
    SqlConnection conn = new SqlConnection(connectiostring);
    SqlCommand cmd = new SqlCommand("select * from Employees", conn);
    conn.Open();
    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
    DataSet data = new DataSet();
    adapter.Fill(data,"Employees");
    data.Tables["Employees"].Columns.Add("Testcolumn");
    DataTable t1 = new DataTable("Employees");
    DataRow newrow = t1.NewRow();
    newrow[0] = "10";\\this the line i am getting error
    newrow[1] = "Pradeep";
    newrow[2] = "Kumar";
    data.Tables["Employees"].Rows.Add(newrow);
    GridView2.DataSource = data;
    GridView2.DataBind();

Please help me Thanks,

You haven't added the columns to the DataTable.

t1.Columns.Add(new DataColumn
                   {
                       DataType = string,
                       ColumnName = "First Name"
                   });

repeat this for each column supplying the correct type for each.

Create a function that adds columns before trying to add rows.. Call the method at InitializeComponents..

ex.
private void InitTbl(DataTable myTbl)
        {
            myTbl.Columns.Add(new DataColumn("id"));
            myTbl.Columns.Add(new DataColumn("fname"));
            myTbl.Columns.Add(new DataColumn("lname"));
        }

You need to add some columns to the table first:

DataTable t1 = new DataTable("Employees");
t1.Columns.Add("column1", typeof(string));
t1.Columns.Add("column2", typeof(string));
t1.Columns.Add("column3", typeof(string));

DataRow newrow = t1.NewRow();
...

I think maybe this is actually your problem.

DataTable t1 = new DataTable("Employees")

This creates a brand new table object that is not part of your dataset.

So you should be replace it with this

DataTable t1 = data.Tables["Employees"]

Which gets the table from the dataset and points the t1 variable at that table.