Bind GridView with Datatable

Add a GridView control, two lable controls, three textbox controls and button control in the page
Create datatable structure.

private DataTable CreateDataTable()
{
DataTable myDataTable = new DataTable();
DataColumn myDataColumn;
myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "id";
myDataTable.Columns.Add(myDataColumn);
myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "username";
myDataTable.Columns.Add(myDataColumn);
myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "firstname";
myDataTable.Columns.Add(myDataColumn);
myDataColumn = new DataColumn();
myDataColumn.DataType = Type.GetType("System.String");
myDataColumn.ColumnName = "lastname";
myDataTable.Columns.Add(myDataColumn);
return myDataTable;
}


Insert data into datatable.

private void AddDataToTable(string username,string firstname,string lastname,DataTable myTable)
{
DataRow row;
row = myTable.NewRow();
row["id"] = Guid.NewGuid().ToString();
row["username"] = username;
row["firstname"] = firstname;
row["lastname"] = lastname;
myTable.Rows.Add(row);
}


//Add data to datatable which we have created

protected void btnAdd_Click(object sender, EventArgs e)
{
if (txtUserName.Text.Trim() == "")
{
this.lblTips.Text = "You must fill a username.";
return;
}
else
{
AddDataToTable(parameter);
this.txtFirstName.Text = "";
this.txtLastName.Text = "";
this.txtUserName.Text = "";
this.lblTips.Text = "";
}
}

// Page Load
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
DataTable myDt = new DataTable();
myDt = CreateDataTable();
this.GridView1.DataSource = myDt
this.GridView1.DataBind();
}
}