如何获取Dropdownbox C＃ASP.NET的Datasource（）

Question

I have table tblDepartments with columns DeptID, Department, Description . I also have dropdownbox drpDepartments . I want to display the contents of column Department on the dropdownbox. I tried using this C# code for winforms but it didn't work:

        drpDepartments.DataSource = dsDep.Tables["tblDepartment"];
        drpDepartments.DisplayMember = "Department";
        drpDepartments.ValueMember = "DeptID";
        drpDepartments.Text = "Choose Department";

How do I do it using ASP.NET C#? Thanks.

New code (still not working)

        sConn = new SqlConnection(sStr);
        daEmp = new SqlDataAdapter("SELECT * FROM tblEmployee", sConn);
        daDep = new SqlDataAdapter("SELECT * FROM tblDepartment", sConn);
        dsEmp = new DataSet();
        dsDep = new DataSet();

        daEmp.Fill(dsEmp, "tblEmployee");
        daDep.Fill(dsDep, "tblDepartment");

        dsEmp.Tables["tblEmployee"].PrimaryKey = new DataColumn[] { dsEmp.Tables["tblEmployee"].Columns["EmployeeID"] };

        DataTable dt=new DataTable();
        daDep.Fill(dt);

        drpDepartments.DataTextField = "Department";
        drpDepartments.DataValueField = "DeptID";
        drpDepartments.DataSource = dt;
        drpDepartments.DataBind();

Answer 1

You have to call it like this in asp.net webForms

        drpDepartments.DataSource = dsDep.Tables["tblDepartment"];// Set DataSource Table First
        drpDepartments.DataTextField = "Department";// Set Column Name of DataTable to set as Text Field
        drpDepartments.DataValueField = "DepartmentID";// Set Column Name of DataTable to set as Value Field
        drpDepartments.DataBind();

You must be using it from using System.Web.UI.WebControls; namespace. It seems like you were using winforms namespaces.

DataTextField is equivalent to DisplayMember and ValueMember is equivalent to DataValueField .

Answer 2

Did you call DataBind()?

drpDepartments.DataSource = dsDep.Tables["tblDepartment"];
drpDepartments.DisplayMember = "Department";
drpDepartments.ValueMember = "DepartmentID";
drpDepartments.Text = "Choose Department";
drpDepartments.DataBind();

Answer 3

drpDepartments.DataSource = ds1;
drpDepartments.DataTextField = "textcol";
drpDepartments.DataValueField = "valuecol";
drpDepartments.DataBind();

after doing this in btn_save method add this..

 cmd.Parameters.AddWithValue("@a", drpDepartments.SelectedValue);

hope it helps.