how to display a datagrid in windows form by selecting a value in dropdown

SqlConnection con = new SqlConnection("DatabaseConnectionString");
SqlCommand cmd = new SqlCommand("SELECT * FROM SomeTable WHERE SomeColumn = '" + DropDown1.SelectedItem.ToString() + "'", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);

DataGrid.DataSource = dt;
DataGrid.DataBind();   // if it is a ASP .NET application