Question

我想将一些值传递给EntityDataSource的参数，例如：

Where="it.ORDER_ID IN {@OrderIdList}"（这是EntityDataSource上的属性）

<WhereParameters>
    <asp:ControlParameter 
       Name="OrderIdList" Type="Int16" 
       ControlID="OrderFilterControl" PropertyName="OrderIdList" 
    />
</WhereParameters>

这不起作用，因为ORDER_ID的类型为int32，我需要传入多个值，例如{1,2,3}等

我接下来尝试的是在代码隐藏中设置Where子句，除了我无法使DropDownLists上的数据绑定工作之外，这一切都有效。我的意思是，EntityDataSource更新事件中的绑定下拉列表没有返回任何值。

我理想的解决方案是在WhereParameter上使用EntityDataSource，但感谢任何帮助。谢谢，托尼。

使用AdventureWorks数据库后的完整代码示例：

Public Class EntityDataSourceWhereInClause
Inherits System.Web.UI.Page

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    CustomersEntityDataSource.Where = WhereClause ''# reset after each postback as its lost otherwise
End Sub

Private Sub cmdFilterCustomers_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdFilterCustomers.Click
    Dim CustomerIdList As New Generic.List(Of Int32)
    For Each item As ListItem In CustomerIdCheckBoxList.Items
        If item.Selected Then
            CustomerIdList.Add(item.Value)
        End If
    Next

    Dim CustomerCsvList As String = String.Join(", ", CustomerIdList.Select(Function(o) o.ToString()).ToArray())
    WhereClause = "it.CustomerID IN {" & CustomerCsvList & "}"

    CustomersEntityDataSource.Where = WhereClause
    FormView1.PageIndex = 0

End Sub

''#  save between postbacks the custom Where IN clause
Public Property WhereClause() As String
    Get
        Return ViewState("WhereClause")
    End Get
    Set(ByVal value As String)
        ViewState.Add("WhereClause", value)
    End Set
End Property

Private Sub CustomersEntityDataSource_Updating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.EntityDataSourceChangingEventArgs) Handles CustomersEntityDataSource.Updating
    Dim c = CType(e.Entity, EntityFrameworkTest.Customer)
    If c.Title.Length = 0 Then
        Response.Write("Title is empty string, so will save like this!")
    End If
End Sub

End Class

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="EntityDataSourceWhereInClause.aspx.vb"
Inherits="EntityFrameworkTest.EntityDataSourceWhereInClause" %>


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
<form id="form1" runat="server">

<%''# filter control %>
<div>
    <asp:EntityDataSource ID="CustomerIdListEntityDataSource" runat="server" ConnectionString="name=AdventureWorksLT2008Entities"
        DefaultContainerName="AdventureWorksLT2008Entities" EnableFlattening="False"
        EntitySetName="Customers" Select="it.[CustomerID]" OrderBy="it.[CustomerID]">
    </asp:EntityDataSource>
    <asp:CheckBoxList ID="CustomerIdCheckBoxList" runat="server" DataSourceID="CustomerIdListEntityDataSource"
        DataTextField="CustomerID" DataValueField="CustomerID" RepeatDirection="Horizontal">
    </asp:CheckBoxList>
    <asp:Button ID="cmdFilterCustomers" runat="server" Text="Apply Filter" />
</div>

<%  
    ''# you get this error passing in CSV in the where clause
    ''# The element type 'Edm.Int32' and the CollectionType 'Transient.collection[Edm.String(Nullable=True,DefaultValue=,MaxLength=,Unicode=,FixedLength=)]' are not compatible. The IN expression only supports entity, primitive, and reference types.  Near WHERE predicate, line 6, column 15. 
    ''# so have coded it manually in code-behind Where="it.CustomerID IN {@OrderIdList}"
%>
<asp:EntityDataSource ID="CustomersEntityDataSource" runat="server" ConnectionString="name=AdventureWorksLT2008Entities"
    DefaultContainerName="AdventureWorksLT2008Entities" EnableFlattening="False"
    EnableUpdate="True" EntitySetName="Customers"
    AutoGenerateOrderByClause="false">
</asp:EntityDataSource>
<%''# updating works with DropDownLists until the Where clause is set in code %>
<asp:FormView ID="FormView1" runat="server" AllowPaging="True" CellPadding="4" DataKeyNames="CustomerID"
    DataSourceID="CustomersEntityDataSource" ForeColor="#333333">
    <EditItemTemplate>
        CustomerID:
        <asp:Label ID="CustomerIDLabel1" runat="server" Text='<%# Eval("CustomerID") %>' />
        <br />
        NameStyle:
        <asp:CheckBox ID="NameStyleCheckBox" runat="server" Checked='<%# Bind("NameStyle") %>' />
        <br />
        Title:
        <%''# the SelectedValue is not Bound to the EF object if the Where clause is updated in code-behind %>
        <asp:DropDownList ID="ddlTitleBound" runat="server" DataSourceID="TitleEntityDataSource"
            DataTextField="Title" DataValueField="Title" AutoPostBack="false" AppendDataBoundItems="true"
            SelectedValue='<%# Bind("Title") %>'>
        </asp:DropDownList>
        <asp:EntityDataSource ID="TitleEntityDataSource" runat="server" ConnectionString="name=AdventureWorksLT2008Entities"
            DefaultContainerName="AdventureWorksLT2008Entities" EnableFlattening="False"
            EntitySetName="Customers" Select="it.[Title]" GroupBy="it.[Title]" ViewStateMode="Enabled">
        </asp:EntityDataSource>
        <br />
        FirstName:
        <asp:TextBox ID="FirstNameTextBox" runat="server" Text='<%# Bind("FirstName") %>' />
        <br />
        MiddleName:
        <asp:TextBox ID="MiddleNameTextBox" runat="server" Text='<%# Bind("MiddleName") %>' />
        <br />
        LastName:
        <asp:TextBox ID="LastNameTextBox" runat="server" Text='<%# Bind("LastName") %>' />
        <br />
        Suffix:
        <asp:TextBox ID="SuffixTextBox" runat="server" Text='<%# Bind("Suffix") %>' />
        <br />
        CompanyName:
        <asp:TextBox ID="CompanyNameTextBox" runat="server" Text='<%# Bind("CompanyName") %>' />
        <br />
        SalesPerson:
        <asp:TextBox ID="SalesPersonTextBox" runat="server" Text='<%# Bind("SalesPerson") %>' />
        <br />
        EmailAddress:
        <asp:TextBox ID="EmailAddressTextBox" runat="server" Text='<%# Bind("EmailAddress") %>' />
        <br />
        Phone:
        <asp:TextBox ID="PhoneTextBox" runat="server" Text='<%# Bind("Phone") %>' />
        <br />
        PasswordHash:
        <asp:TextBox ID="PasswordHashTextBox" runat="server" Text='<%# Bind("PasswordHash") %>' />
        <br />
        PasswordSalt:
        <asp:TextBox ID="PasswordSaltTextBox" runat="server" Text='<%# Bind("PasswordSalt") %>' />
        <br />
        rowguid:
        <asp:TextBox ID="rowguidTextBox" runat="server" Text='<%# Bind("rowguid") %>' />
        <br />
        ModifiedDate:
        <asp:TextBox ID="ModifiedDateTextBox" runat="server" Text='<%# Bind("ModifiedDate") %>' />
        <br />
        <asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" CommandName="Update"
            Text="Update" />
        &nbsp;<asp:LinkButton ID="UpdateCancelButton" runat="server" CausesValidation="False"
            CommandName="Cancel" Text="Cancel" />
    </EditItemTemplate>
    <EditRowStyle BackColor="#999999" />
    <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
    <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
    <ItemTemplate>
        CustomerID:
        <asp:Label ID="CustomerIDLabel" runat="server" Text='<%# Eval("CustomerID") %>' />
        <br />
        NameStyle:
        <asp:CheckBox ID="NameStyleCheckBox" runat="server" Checked='<%# Bind("NameStyle") %>'
            Enabled="false" />
        <br />
        Title:
        <asp:Label ID="TitleLabel" runat="server" Text='<%# Bind("Title") %>' />
        <br />
        FirstName:
        <asp:Label ID="FirstNameLabel" runat="server" Text='<%# Bind("FirstName") %>' />
        <br />
        MiddleName:
        <asp:Label ID="MiddleNameLabel" runat="server" Text='<%# Bind("MiddleName") %>' />
        <br />
        LastName:
        <asp:Label ID="LastNameLabel" runat="server" Text='<%# Bind("LastName") %>' />
        <br />
        Suffix:
        <asp:Label ID="SuffixLabel" runat="server" Text='<%# Bind("Suffix") %>' />
        <br />
        CompanyName:
        <asp:Label ID="CompanyNameLabel" runat="server" Text='<%# Bind("CompanyName") %>' />
        <br />
        SalesPerson:
        <asp:Label ID="SalesPersonLabel" runat="server" Text='<%# Bind("SalesPerson") %>' />
        <br />
        EmailAddress:
        <asp:Label ID="EmailAddressLabel" runat="server" Text='<%# Bind("EmailAddress") %>' />
        <br />
        Phone:
        <asp:Label ID="PhoneLabel" runat="server" Text='<%# Bind("Phone") %>' />
        <br />
        PasswordHash:
        <asp:Label ID="PasswordHashLabel" runat="server" Text='<%# Bind("PasswordHash") %>' />
        <br />
        PasswordSalt:
        <asp:Label ID="PasswordSaltLabel" runat="server" Text='<%# Bind("PasswordSalt") %>' />
        <br />
        rowguid:
        <asp:Label ID="rowguidLabel" runat="server" Text='<%# Bind("rowguid") %>' />
        <br />
        ModifiedDate:
        <asp:Label ID="ModifiedDateLabel" runat="server" Text='<%# Bind("ModifiedDate") %>' />
        <br />
        <asp:LinkButton ID="EditButton" runat="server" CausesValidation="False" CommandName="Edit"
            Text="Edit" />
    </ItemTemplate>
    <PagerSettings Position="Top" />
    <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
    <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
</asp:FormView>
</form>

Answer 1

经过多次浪费，我现在有了工作！

与FormView分页相关的问题以及在编辑所有内容时将AllowPaging设置为False都没问题。

只有在HTML中的FormView上有以下内容时才会出现这种情况：

<PagerSettings Mode="NextPrevious" Position="Top" />

使用默认分页时，您看不到问题。

Answer 2

下面的替代解决方法，如果禁用了分页并且您仍有问题：

Private Sub DetailsView1_ModeChanged(sender As Object, e As System.EventArgs) Handles DetailsView1.ModeChanged
        EntityDataSource1.Where = "it.[ID]=" & Me.lstFilter.SelectedValue  ' DetailView.Edit work-around for lost context: Reset bound EntityDataSource.Where
Sub

如何实现EntityDataSource IN实体的sql子句

2 个答案: