GridView，它必須是IListSource，IEnumerable或IDataSource

Question

這是我的源代碼

<asp:GridView ID="gveducationInfo" CssClass="footable" runat="server" AutoGenerateColumns="false" Style="max-width: 600px" ShowHeaderWhenEmpty="true" DataKeyNames="Education_ID" OnRowCommand="gveducationInfo_RowCommand">
    <Columns>
        <asp:BoundField DataField="Education_ID" HeaderText="" ItemStyle-CssClass="hiddenColumn" HeaderStyle-CssClass="hiddenColumn" />
        <asp:BoundField DataField="Degree_Type" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Year_Of_Passing" HeaderText="Year Of Passing" />
        <asp:BoundField DataField="Institute_Name" HeaderText="Institute Name" />
        <asp:BoundField DataField="State_ID" HeaderText="State" />
        <asp:BoundField DataField="City_ID" HeaderText="City" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <%--<asp:BoundField DataField="Notes" HeaderText="Notes" />--%>
        <asp:ButtonField ButtonType="Image" ImageUrl="~/images/edit16.png" CommandName="EditRow" ItemStyle-CssClass="align-center" />
        <asp:ButtonField ButtonType="Image" ImageUrl="~/images/delete16.png" CommandName="DeleteRow" ItemStyle-CssClass="align-center" />
    </Columns>
</asp:GridView>

這是我的C＃編碼

protected void butSave_ServerClick(object sender, EventArgs e)
{
    Business.ATS.ATS ats = new Business.ATS.ATS();
    Data.Education_Info education_Info = new Data.Education_Info();
    var state = ats.GetStates();
    var city = ats.GetCities();
    education_Info = ats.GetEducationInfo(Applicant_ID).SingleOrDefault();
    education_Info = new Data.Education_Info();
    education_Info.Education_ID = 0;
    education_Info.Applicant_ID = Applicant_ID;
    education_Info.Name = txtdegreename.Value;
    education_Info.Year_Of_Passing = txtyearofpassing.Value;
    education_Info.Institute_Name = txtnameofinstitution.Value;
    education_Info.City_ID = Convert.ToInt32(ddlcity.SelectedValue);
    education_Info.State_ID = Convert.ToInt32(ddlstate.SelectedValue);
    education_Info.Degree_Type = Convert.ToInt32(ddldegreetype.SelectedValue);
    ats.SaveEducationalInfo(education_Info);
    gveducationInfo.DataSource = ats.GetEduInfo().Last();
    gveducationInfo.DataBind();
}

這是我的實體框架數據庫代碼

public IList<Education_Info> GetEduInfo()
{
    using (Data.ATSEntities dc = new Data.ATSEntities())
    {
        var lsteducationinfo = dc.Education_Info.ToList();
        return lsteducationinfo;
    }
}

當我填寫網頁中的詳細信息並單擊保存頁面時，我需要獲取用戶在gridview中輸入的最后一條記錄，請輸入錯誤

數據源是無效類型。 它必須是IListSource，IEnumerable或IDataSource。

有誰知道如何騎它？

Answer 1

這里調用Last()是個問題：

gveducationInfo.DataSource = ats.GetEduInfo().Last();

刪除對Last()的調用，如下所示：

gveducationInfo.DataSource = ats.GetEduInfo();

為什么？

GetEduInfo方法返回IList ， IList實現IEnumerable ，它將與DataSource 。 但是，當你調用Last()時，你不再傳遞IEnumerable ，而是傳遞序列的最后一項，這將無法工作。

如果要將單個項綁定到DataSource ，則需要將其作為IEnumerable包裝起來。 您可以使用任何答案將單個項目傳遞為IEnumerable <T> ，例如將單個項目包裝在數組中：

gveducationInfo.DataSource = new Education_Info[] {ats.GetEduInfo().Last()};