DataGrid+DropDownList绑定已没问题,如何实现在编辑这一行时,DropDownList可以停在数据库里数据所处的位置？

[hornbills]

Sub MyDataGrid_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles MyDataGrid.ItemDataBound
Dim mg as new ManageDB
Dim DS as DataSet
DS=mg.GetCompanyByID(MyDataGrid.DataKeys(Cint(E.Item.ItemIndex)))

If e.Item.ItemType = ListItemType.EditItem Then
Dim myDropDownList As New DropDownList
myDropDownList = CType(e.Item.FindControl("ddlCompanyArea"), DropDownList)
myDropDownList.DataSource = BindCompanyArea()
myDropDownList.DataTextField = "Company_Area"
myDropDownList.DatavalueField = "ID"
myDropDownList.DataBind()
myDropDownList.SelectedIndex=myDropDownList.Items.IndexOf(myDropDownList.Items.FindbyValue(DS.Tables(0).ROWS(0).Item("id_company_area").ToString))


End If
End Sub

我认为问题在这一句
mg.GetCompanyByID(MyDataGrid.DataKeys(Cint(E.Item.ItemIndex)))
E.Item.ItemIndex取出值是-1，MyDataGrid.DataKeys出错

但不知道如何处理？

[glacier111]

帮顶

[tianyi_hsy]

E.Item.ItemIndex为－1时是DataGrid的头，为0时才是第一行，
你把代码放到if(E.Item.ItemIndex != -1)中应该能解决

[lswweb]

if(e.Item.ItemIndex>=0)
{
//你的执行代码
}

[hy_lihuan]

E.Item.ItemIndex>=0

[wwwhang]

DataRowView rowitem = (DataRowView)e.Row.DataItem;
DropDownList clsname = (DropDownList)e.Row.FindControl("uclassname");
if (rowitem["ClassName"] != DBNull.Value)
{
clsname.Items.FindByText(rowitem["ClassName"].ToString()).Selected = true;
}

[hornbills]

微软提供的答案

Sub MyDataGrid_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles MyDataGrid.ItemDataBound
If e.Item.ItemType = ListItemType.EditItem Then
dim DRV as DataRowView=CType(e.Item.DataItem,DataRowView)
Dim CurrentValue1 As String=DRV("Product_Status")
Dim CurrentValue2 As String=DRV("Product_Trouble")

Dim item As ListItem
Dim myDropDownList As New DropDownList

myDropDownList = CType(e.Item.FindControl("ddlProductStatus"), DropDownList)
myDropDownList.DataSource = BindProductStatus()
myDropDownList.DataTextField = "Product_Status"
myDropDownList.DatavalueField = "ID"
myDropDownList.DataBind()
item=myDropDownList.Items.FindByText(CurrentValue1)
If Not item Is Nothing Then Item.Selected=True

myDropDownList = CType(e.Item.FindControl("ddlProductTrouble"), DropDownList)
myDropDownList.DataSource = BindProductTrouble()
myDropDownList.DataTextField = "Product_Trouble"
myDropDownList.DatavalueField = "ID"
myDropDownList.DataBind()
item=myDropDownList.Items.FindByText(CurrentValue2)
If Not item Is Nothing Then Item.Selected=True
'注意，当比较字符串的时候Nchar类型字段是要经过处理才行，否则更换成NvChar
End If
End Sub