Grid View for ASP.NET Web Forms - How to edit grid data using a two-way data-bound grid lookup in dynamic item load mode

This example demonstrates how to add a grid lookup editor to a column edit item template, bind the editor to a large data source, and enable its dynamic item load mode.

Grid Lookup in dynamic item load

Overview

Create a combo box column and specify its EditItemTemplate property. Add a grid lookup control to the template, bind it to a LinqServerModeDataSorce, and use the Bind method to bind the control's Value property to the corresponding field in the main grid's data source.

ASPx
<dx:ASPxGridView ID="ASPxGridView1" runat="server" DataSourceID="SqlDataSource1" KeyFieldName="ProductID"  
    AutoGenerateColumns="False" ClientIDMode="AutoID" >  
    <Columns>  
        <!-- ... -->  
        <dx:GridViewDataComboBoxColumn FieldName="CategoryID" VisibleIndex="2">  
            <PropertiesComboBox TextField="CategoryName" ValueField="CategoryID" ValueType="System.String"  
                IncrementalFilteringMode="Contains" EnableCallbackMode="true" CallbackPageSize="7"  
                OnItemRequestedByValue="ItemRequestedByValue"  
                OnItemsRequestedByFilterCondition="ItemsRequestedByFilterCondition">  
            </PropertiesComboBox>  
            <EditItemTemplate>  
                <dx:ASPxGridLookup ID="ASPxGridLookup1" runat="server" KeyFieldName="CategoryID"  
                    AutoGenerateColumns="False" DataSourceID="LinqServerModeDataSource1"  
                    TextFormatString="{1}" Value='<%# Bind("CategoryID") %>'  
                    IncrementalFilteringMode="Contains">  
                    <GridViewProperties>  
                        <SettingsBehavior AllowFocusedRow="True" AllowSelectSingleRowOnly="True" />  
                    </GridViewProperties>  
                    <Columns>  
                        <!-- ... -->  
                    </Columns>  
                </dx:ASPxGridLookup>  
            </EditItemTemplate>  
        </dx:GridViewDataComboBoxColumn>  
    </Columns>  
</dx:ASPxGridView>

Set the column's EnableCallbackMode property to true to enable the database server mode and handle the following server-side events to dynamically load items in the grid lookup:

ASPxComboBox.ItemRequestedByValue event obtains selected items specified by their values.
ASPxComboBox.ItemsRequestedByFilterCondition event selects items by filter conditions.

C#
public void ItemRequestedByValue(object source, DevExpress.Web.ListEditItemRequestedByValueEventArgs e){  
    int value = 0;  
    if(e.Value == null || !Int32.TryParse(e.Value.ToString(), out value))  
        return;  
    ASPxComboBox comboBox = (ASPxComboBox)source;  
    DataClassesDataContext dataContext = new DataClassesDataContext();  
    int id = Int32.Parse(e.Value.ToString());  
    var query = from category in dataContext.Categories  
                where category.CategoryID == id  
                select category;  
    var count = query.Count();  
    comboBox.DataSource = query;  
    comboBox.DataBind();  
}  

public void ItemsRequestedByFilterCondition(object source, DevExpress.Web.ListEditItemsRequestedByFilterConditionEventArgs e){  
    ASPxComboBox comboBox = (ASPxComboBox)source;  
    var skip = e.BeginIndex;  
    var take = e.EndIndex - e.BeginIndex + 1;  
    DataClassesDataContext dataContext = new DataClassesDataContext();  
    var queryStartWidth =  
        (from category in dataContext.Categories  
            where category.CategoryName.StartsWith(e.Filter)  
            orderby category.CategoryName  
            select category).Skip(skip).Take(take);  
    comboBox.DataSource = queryStartWidth;  
    comboBox.DataBind();  
}

Documentation

Example Code

WebSite/Default.aspx

ASPx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register assembly="DevExpress.Web.v15.1, Version=15.1.15.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" namespace="DevExpress.Data.Linq" tagprefix="dx" %>
<%@ Register Assembly="DevExpress.Web.v15.1, Version=15.1.15.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" Namespace="DevExpress.Web" TagPrefix="dx" %>



<!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">
    <dx:ASPxGridView ID="ASPxGridView1" runat="server" AutoGenerateColumns="False" 
        ClientIDMode="AutoID" DataSourceID="SqlDataSource1" KeyFieldName="ProductID">
        <Columns>
            <dx:GridViewCommandColumn VisibleIndex="0" ShowEditButton="True" ShowNewButton="true"/>
            <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" 
                VisibleIndex="0">
                <EditFormSettings Visible="False" />
            </dx:GridViewDataTextColumn>
            <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
            </dx:GridViewDataTextColumn>
            <dx:GridViewDataComboBoxColumn FieldName="CategoryID" VisibleIndex="2">
                <PropertiesComboBox TextField="CategoryName" ValueField="CategoryID" ValueType="System.String" IncrementalFilteringMode="Contains" EnableCallbackMode="true" CallbackPageSize="7"
                    OnItemRequestedByValue="ItemRequestedByValue" OnItemsRequestedByFilterCondition="ItemsRequestedByFilterCondition">
                </PropertiesComboBox>
                <EditItemTemplate>
                    <dx:ASPxGridLookup ID="ASPxGridLookup1" runat="server" 
                        AutoGenerateColumns="False" DataSourceID="LinqServerModeDataSource1" 
                        KeyFieldName="CategoryID" TextFormatString="{1}" 
                        Value='<%# Bind("CategoryID") %>' IncrementalFilteringMode="Contains">
                        <GridViewProperties>
                            <SettingsBehavior AllowFocusedRow="True" AllowSelectSingleRowOnly="True" />
                        </GridViewProperties>
                        <Columns>
                            <dx:GridViewDataTextColumn FieldName="CategoryID" VisibleIndex="0">
                            </dx:GridViewDataTextColumn>
                            <dx:GridViewDataTextColumn FieldName="CategoryName" VisibleIndex="2">
                            </dx:GridViewDataTextColumn>
                            <dx:GridViewDataTextColumn FieldName="Description" VisibleIndex="3">
                            </dx:GridViewDataTextColumn>
                        </Columns>
                    </dx:ASPxGridLookup>
                    
                </EditItemTemplate>
            </dx:GridViewDataComboBoxColumn>
        </Columns>
    </dx:ASPxGridView>
    <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>" 
        DeleteCommand="DELETE FROM [Products] WHERE [ProductID] = @ProductID" 
        InsertCommand="INSERT INTO [Products] ([ProductName], [CategoryID]) VALUES (@ProductName, @CategoryID)" 
        SelectCommand="SELECT [ProductID], [ProductName], [CategoryID] FROM [Products]" 
        UpdateCommand="UPDATE [Products] SET [ProductName] = @ProductName, [CategoryID] = @CategoryID WHERE [ProductID] = @ProductID">
        <DeleteParameters>
            <asp:Parameter Name="ProductID" Type="Int32" />
        </DeleteParameters>
        <InsertParameters>
            <asp:Parameter Name="ProductName" Type="String" />
            <asp:Parameter Name="CategoryID" Type="Int32" />
        </InsertParameters>
        <UpdateParameters>
            <asp:Parameter Name="ProductName" Type="String" />
            <asp:Parameter Name="CategoryID" Type="Int32" />
            <asp:Parameter Name="ProductID" Type="Int32" />
        </UpdateParameters>
    </asp:SqlDataSource>
    <br />
    <dx:LinqServerModeDataSource ID="LinqServerModeDataSource1" runat="server" ContextTypeName="DataClassesDataContext" TableName="Categories"/>
    </form>
</body>
</html>

WebSite/Default.aspx.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DevExpress.Web;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e) {
    }

    public void ItemRequestedByValue(object source, DevExpress.Web.ListEditItemRequestedByValueEventArgs e){
        int value = 0;
        if(e.Value == null || !Int32.TryParse(e.Value.ToString(), out value))
            return;

        ASPxComboBox comboBox = (ASPxComboBox)source;

        DataClassesDataContext dataContext = new DataClassesDataContext();

        int id = Int32.Parse(e.Value.ToString());
        var query = from category in dataContext.Categories
                    where category.CategoryID == id
                    select category;

        var count = query.Count();

        comboBox.DataSource = query;
        comboBox.DataBind();
    }

    public void ItemsRequestedByFilterCondition(object source, DevExpress.Web.ListEditItemsRequestedByFilterConditionEventArgs e){
        ASPxComboBox comboBox = (ASPxComboBox)source;

        var skip = e.BeginIndex;
        var take = e.EndIndex - e.BeginIndex + 1;

        DataClassesDataContext dataContext = new DataClassesDataContext();
        var queryStartWidth =
            (from category in dataContext.Categories
             where category.CategoryName.StartsWith(e.Filter)
             orderby category.CategoryName
             select category).Skip(skip).Take(take);

        comboBox.DataSource = queryStartWidth;
        comboBox.DataBind();
    }
}

Visual Basic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports DevExpress.Web

Partial Public Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    End Sub

    Public Sub ItemRequestedByValue(ByVal source As Object, ByVal e As DevExpress.Web.ListEditItemRequestedByValueEventArgs)
        Dim value As Integer = 0
        If e.Value Is Nothing OrElse Not Int32.TryParse(e.Value.ToString(), value) Then
            Return
        End If

        Dim comboBox As ASPxComboBox = DirectCast(source, ASPxComboBox)

        Dim dataContext As New DataClassesDataContext()

        Dim id As Integer = Int32.Parse(e.Value.ToString())
        Dim query = From category In dataContext.Categories
            Where category.CategoryID = id
            Select category

        Dim count = query.Count()

        comboBox.DataSource = query
        comboBox.DataBind()
    End Sub

    Public Sub ItemsRequestedByFilterCondition(ByVal source As Object, ByVal e As DevExpress.Web.ListEditItemsRequestedByFilterConditionEventArgs)
        Dim comboBox As ASPxComboBox = DirectCast(source, ASPxComboBox)

        Dim skip = e.BeginIndex
        Dim take = e.EndIndex - e.BeginIndex + 1

        Dim dataContext As New DataClassesDataContext()
        Dim queryStartWidth = (
            From category In dataContext.Categories
            Where category.CategoryName.StartsWith(e.Filter)
            Order By category.CategoryName
            Select category).Skip(skip).Take(take)

        comboBox.DataSource = queryStartWidth
        comboBox.DataBind()
    End Sub
End Class

DevExpress Support Team

last modified 2 years ago

Modified: May 19, 2023 12:56 PM

Platform: ASP.NET Web Forms

Product: ASPxGridView

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Grid View for ASP.NET Web Forms - How to edit grid data using a two-way data-bound grid lookup in dynamic item load mode

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