我想将一些值传递给 EntityDataSource 的参数，例如:Where="it.ORDER_ID IN {@OrderIdList}"(这是 EntityDataSource 上的一个属性)
<WhereParameters>
<asp:ControlParameter
Name="OrderIdList" Type="Int16"
ControlID="OrderFilterControl" PropertyName="OrderIdList"
/>
</WhereParameters>
这不起作用，因为
ORDER_ID 是 int32 类型，我需要传入多个值，例如{1,2,3} 等我尝试的下一件事是在代码隐藏中设置
Where 子句，这一切都有效，只是我无法在 DropDownLists 上绑定(bind)数据。我的意思是，EntityDataSource 更新事件中的绑定(bind)下拉列表没有返回任何值。我的理想解决方案是在
WhereParameter 上使用 EntityDataSource 但任何帮助表示赞赏。谢谢，托尼。下面是一个使用 AdventureWorks 数据库的完整代码示例:
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" />
<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>
最佳答案
经过许多浪费的时间，我现在可以正常工作了!
与 FormView 分页相关的问题以及通过在编辑时将 AllowPaging 设置为 False 一切正常。
仅当您在 HTML 中的 FormView 上具有以下内容时才会发生这种情况:
<PagerSettings Mode="NextPrevious" Position="Top" />
使用默认分页，您看不到问题。
关于entity-framework - 如何实现 EntityDataSource Where IN 实体 sql 子句，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/2768953/