how to bind gridview to sqldatasource to our own created form - asp.net

Question

I have a form and 'Add' button. when i click on add then i insert data into database and also i have sqldatasource in which i specify only select,update,delete commands. when i insert data on Add button then i want to refresh and fill the grid automatically.
my sqldatasource id is "sqldatasourceDenter" and i have specified it in my gridview datasourceID="sqldatasourceDenter".
i have tried this
GridView1.DataSourceID = sqldatasourceDenter;
it gives me the error cannot convert sqldatasource to string
i have also defined datasource but it tells both me both datasource, datasourceID cannot be defined.
I actually want to insert data on my 'Add' button then refresh the sqldataSourceDenter to fill the grid.
This is my add button click event function:
..... add_Click(object sender, EventArgs e){
..
.... /* here i have other code*/
.....
else {
string dentername = dname.Text.ToString();
string denteraddress = daddress.Text.ToString();
string dentercontact = dcontact.Text.ToString();
//create sql inset query and take to insert query ftn for execution
string dquery = string.Format("INSERT INTO Denters(D_NIC, D_Name, D_Address, D_Contact) VALUES('{0}','{1}','{2}','{3}')", denternic, dentername, denteraddress, dentercontact);
InsertIntoDB.InsertQuery(dquery);
if (InsertIntoDB.count > 0)
{
gvDenter.DataSourceID = SqlDataSourceDenter;
Response.Write("<script>alert('Denter added successfully')</script>");
InsertIntoDB.count = 0;
ClearDenterFields();
}
}
}
My aspx code is:
<asp:SqlDataSource ID="SqlDataSourceDenter" runat="server" ConnectionString="<%$ ConnectionStrings:VehiclesSystemConnectionString2 %>"
SelectCommand="SELECT [D_NIC], [D_Name], [D_Address], [D_Contact] FROM [Denters]">
</asp:SqlDataSource>
<asp:GridView ID="gvDenter" Visible="False" DataKeyNames="D_NIC" runat="server" AutoGenerateColumns="False" DataSourceID="SqlDataSourceDenter" >
</asp:GridView>

Answer 1

You can have something like
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindDataToGrid();
}
}
protected void BindDataToGrid()
{
string conString = ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
DataTable dt = new DataTable();
using (SqlConnection con = new SqlConnection(conString))
{
string myQuery = "SELECT * FROM MYTABLE";
SqlCommand cmd = new SqlCommand(myQuery);
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
con.Open();
sda.SelectCommand = cmd;
sda.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
}
}
}
protected void Add(object sender, EventArgs e)
{
//Insert To DB Code here
}