ASP.NET 详细信息视图。如何绑定不在对象数据源中的值

Question

我有一个绑定到对象数据源 (ODS) 的 ASP.NET DetailsView。我有用于 ODS OnSelecting 事件的方法，在此方法中，我们根据从对象数据源返回的字段进行另一个数据库查找以获得记录的“风险”值。

我的问题是如何绑定/评估并显示这个额外的“风险”字段，我一直觉得很困难，因为它没有将数据源绑定到详细信息视图。

我尝试将 Label 控件添加到 DetailsView ItemTemplate，但您无法向控件添加 ID 以在后面的代码中引用它。有任何想法吗？

更新这里的一些代码

这里有一些我正在尝试做的简单示例代码

 <asp:DetailsView ID="DetailsView1" runat="server" DataSourceID="ObjectDataSource1">
        <Fields>
            <asp:TemplateField ShowHeader="False">
                <ItemTemplate>
                    <div style="float: right">
                        <asp:Label  runat="server" Text="NEED RISK HERE"></asp:Label>
                    </div>
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:Button ID="ButtonUpdate" runat="server" CausesValidation="True" CommandName="Update"
                        Text="Update" />
                    &nbsp;
                    <asp:Button ID="ButtonCancelUpdates" runat="server" CausesValidation="False" CommandName="Cancel"
                        Text="Cancel" />
                </EditItemTemplate>
            </asp:TemplateField>
        </Fields>
    </asp:DetailsView>
    <br />
    <br />
    <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" OnSelecting="ods1_Selecting"
        SelectMethod="GetMemoryDataTable" TypeName="AspMemoryDatatableDemo.MemoryDataTableProvider">
    </asp:ObjectDataSource>

代码背后

  public String GetRisk()
    {
        return "HIGH";
    }


    protected void ods1_Selecting(object sender, ObjectDataSourceSelectingEventArgs e)
    {
      // Get Risk based on row data
      // Need some way of showing this in the DetailsView

        GetRisk();
    }

数据集实际上来自数据实体，但在此示例中，我只使用内存数据表。

Answer 1

我会尽力为您提供帮助，但如果您向我们展示一些此类问题的代码，那将真的很有帮助。您是否尝试过向对象数据源添加列？我假设您有某种数据表（如果没有，请将其转换为数据表）。所以让我们添加一列并重新绑定它...

---

HTML

<div>

<asp:GridView id="myGridView" AutoGenerateColumns="true" runat="server">

</asp:GridView>
    <br />
    <asp:TextBox ID="column_name" runat="server"></asp:TextBox>
    <asp:Button ID="addColumn" Text="Add Column" runat="server" />
</div>

---

VB.NET

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load

    ' ===========================================================================
    '  This section is just to create a datatable. I assume you are already have one 
    '      that gets retrieved from a database somewhere.
    Dim dt As New DataTable ' create new test datatable

    With dt.Columns ' add columns to datatable
        .Add("id").AutoIncrement = True
        .Add("value")
    End With

    For i = 1 To 4 ' add some rows and values to the datatable.
        Dim msg = String.Empty
        Select Case i
            Case 1
                msg = "this"
            Case 2
                msg = "is"
            Case 3
                msg = "a test"
            Case 4
                msg = "table"
        End Select
        Dim r As DataRow = dt.NewRow()
        r("value") = msg
        dt.Rows.Add(r)
    Next i
    ' ===========================================================================

    myGridView.DataSource = dt ' set our datasource
    myGridView.DataBind() ' bind our data source

End Sub


Protected Sub addColumn_Click(sender As Object, e As EventArgs) Handles addColumn.Click
    Dim dt As DataTable = DirectCast(myGridView.DataSource, DataTable) ' get the current datatable used by your gridview.
    If Not String.IsNullOrWhiteSpace(column_name.Text) Then ' check if the new column name is null or empty.
        dt.Columns.Add(column_name.Text).DefaultValue = "new value" ' just here to add a default value. yours presumably will already have a value.
        myGridView.DataSource = dt ' update the datasource.
        myGridView.DataBind() ' bind the new datasource.

    End If
End Sub

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添加列前的页面

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添加列后的页面