请教.为什么我的datagrid的selectindex总是0

Question

这是我的在datagrid的selectindexchange事件里一段代码
Dim Index As Integer
        Index = ProjectDataGrid.SelectedIndex
        Dim DGI As DataGridItem
        DGI = ProjectDataGrid.SelectedItem        Dim DBS As New DataBaseAccess
        DBS.SetConn()
        Dim Con As OracleConnection
        Con = DBS.GetConn
        Dim Ds As New DataSet
        If Session("role") = "业务员" Then
            ProjectQueryAdapter.SelectCommand.CommandText = ProjectQueryAdapter.SelectCommand.CommandText & " where " & """T_B_CRM_Project""" & "." & """Employ_id2""" & "='" & Session("empid") & "'"
        End If        ProjectQueryAdapter.SelectCommand.Connection = Con
        ProjectQueryAdapter.Fill(Ds, "Project")
        Dim ProjectId As String
        If DGI.Cells(0).Text <> "" Then
            ProjectId = DGI.Cells(0).Text
        Else
            ProjectId = Ds.Tables("Project").Rows(Index)("项目编号")
        End If
    Response.Redirect("ProjectQueryDetails.aspx?projectid=" & ProjectId)
为什么我的datagrid的selectindex总是0