这里我开发了以下代码

Here I have Developed following code

static DataTable dt;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        dt = new DataTable();
        dt.Columns.Add("Project Number");
        dt.Columns.Add("Title");
        dt.Columns.Add("Activity");
    }
    GridView1.DataSource = dt;
    GridView1.DataBind();
}

protected void Button1_Click(object sender, EventArgs e)
{
    DataRow dr = dt.NewRow();
    dr[0] =  DropDownList1.SelectedValue;
    dr[1] =  DropDownList2.SelectedValue;
    dr[2] =  DropDownList3.SelectedValue;
    dt.Rows.Add(dr);
    GridView1.DataSource = dt;
    GridView1.DataBind();
}

我希望这会对你有所帮助

I hope this will be helpful to you

尝试级联下拉菜单 -

http://www.asp.net/ajaxLibrary /AjaxControlToolkitSampleSite/CascadingDropDown/CascadingDropDown.aspx [ ^ ]

http://www.asp.net/ ajaxLibrary / AjaxControlToolkitSampleSite / Walkthrough / CCDWithDB.aspx [ ^ ]

http://code.msdn.microsoft.com/CSASPNETCascadingDropDownLi -0 a3f1ecf [ ^ ]

Try cascading dropdowns -
http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/CascadingDropDown/CascadingDropDown.aspx[^]
http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/Walkthrough/CCDWithDB.aspx[^]
http://code.msdn.microsoft.com/CSASPNETCascadingDropDownLi-0a3f1ecf[^]

请按照以下示例：

Follow this example:

Protected Sub btnSaveEmail_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSaveEmail.Click
        dt_email = Session("dt_email") 'OR Dim dt_email As New DataTable

        Dim dr As DataRow
        dr = dt_email.NewRow()

        dr("intCodigoClienteEmail") = Cint(DropDownList.Selectedvalue)
        dr("intCodigoCliente") = Cint(DropDownList.Selectedvalue)
        dr("vchEmail") = Cint(DropDownList.Selectedvalue)

        dt_email.Rows.Add(dr)

        grdEmail.DataSource = dt_email
        grdEmail.DataBind()

        Session("dt_email") = dt_email
    End Sub

首先，您可以创建一个数据表，或者可以创建一个新的数据表，然后通过添加一行作为所选值来创建数据表DataRow。

毕竟完成后，使用datarow加载数据表。

之后加载带有数据表的网格

First you take a datatable existing OR can create a new one, then create a datatable DataRow this by adding a line as the selected values​​.
After all done, load the datatable with the datarow.
After that load the grid with datatable