ASPxGridView.DetailRowGetButtonVisibility Event

Enables you to hide/show expand buttons displayed within individual data rows.

Assembly: DevExpress.Web.v18.2.dll

Declaration

C#
VB.NET

public event ASPxGridViewDetailRowButtonEventHandler DetailRowGetButtonVisibility

Public Event DetailRowGetButtonVisibility As ASPxGridViewDetailRowButtonEventHandler

Event Data

The DetailRowGetButtonVisibility event's data class is ASPxGridViewDetailRowButtonEventArgs. The following properties provide information specific to this event:

Property	Description
ButtonState	Gets or sets the button’s state.
IsExpanded	Gets whether the processed data row is expanded.
KeyValue	Gets an object that uniquely identifies the data row. Inherited from ASPxGridViewItemEventArgs.
VisibleIndex	Gets the visible index of the data row. Inherited from ASPxGridViewItemEventArgs.

Remarks

The DetailRowGetButtonVisibility event is raised for each data row, and allows you to hide/show their expand buttons. You can handle it to hide expand buttons for data rows whose details have no data.

Use the ASPxGridViewDetailRowButtonEventArgs.ButtonState property to specify the button’s state. The event parameter’s ASPxGridViewItemEventArgs.KeyValue property identifies the processed row. To obtain whether the processed row is exapanded, use the ASPxGridViewDetailRowButtonEventArgs.IsExpanded property.

Note

The DetailRowGetButtonVisibility event isn’t raised if the ASPxGridViewDetailSettings.ShowDetailButtons option is disabled.

Example

This example illustrates how to hide the detail button for "empty" detail rows using the server-side DetailRowGetButtonVisibility event

Note

A complete sample project is available at https://github.com/DevExpress-Examples/aspxgridview-how-to-hide-the-detail-button-if-the-detail-grid-is-empty-e2537

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

<%@ Register Assembly="DevExpress.Web.v13.2, Version=13.2.13.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxGridView" TagPrefix="dx" %>
<%@ Register Assembly="DevExpress.Web.v13.2, Version=13.2.13.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxEditors" 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>How to hide the detail button if the detail grid is empty</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <br />
        <br />
    </div>
    <dx:ASPxGridView ID="mainGrid" runat="server" AutoGenerateColumns="False" DataSourceID="masterDataSource"
        KeyFieldName="CategoryID" OnDataBinding="masterGrid_DataBinding" OnDetailRowGetButtonVisibility="masterGrid_DetailRowGetButtonVisibility">
        <Templates>
            <DetailRow>
                <dx:ASPxGridView ID="detailGrid" runat="server" AutoGenerateColumns="False" DataSourceID="dsDetail"
                    KeyFieldName="ProductID" OnBeforePerformDataSelect="detailGrid_BeforePerformDataSelect"
                    Width="100%">
                    <Styles>
                        <DetailRow HorizontalAlign="Justify">
                        </DetailRow>
                    </Styles>
                    <Columns>
                        <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" VisibleIndex="0">
                            <EditFormSettings Visible="False" />
                        </dx:GridViewDataTextColumn>
                        <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
                        </dx:GridViewDataTextColumn>
                        <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="2">
                        </dx:GridViewDataTextColumn>
                    </Columns>
                </dx:ASPxGridView>
            </DetailRow>
        </Templates>
        <Columns>
            <dx:GridViewDataTextColumn FieldName="CategoryID" ReadOnly="True" VisibleIndex="0">
                <EditFormSettings Visible="False" />
            </dx:GridViewDataTextColumn>
            <dx:GridViewDataTextColumn FieldName="CategoryName" VisibleIndex="1">
            </dx:GridViewDataTextColumn>
            <dx:GridViewDataTextColumn FieldName="Description" VisibleIndex="2">
            </dx:GridViewDataTextColumn>
        </Columns>
        <SettingsDetail ShowDetailRow="True" />
    </dx:ASPxGridView>
    <asp:AccessDataSource ID="dsDetail" runat="server" DataFile="~/App_Data/nwind.mdb"
        SelectCommand="SELECT [ProductID], [ProductName], [CategoryID], [UnitPrice] FROM [Products]  WHERE ([CategoryID] = ?)">
        <SelectParameters>
            <asp:SessionParameter DefaultValue="CategoryID" Name="CategoryID" SessionField="CategoryID"
                Type="Int32" />
        </SelectParameters>
    </asp:AccessDataSource>
    <asp:AccessDataSource ID="masterDataSource" runat="server" DataFile="~/App_Data/nwind.mdb"
        SelectCommand="SELECT * FROM [Categories]"></asp:AccessDataSource>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DevExpress.Web.ASPxGridView;
using DevExpress.Web.Data;
using System.Drawing;
using System.Collections;
using System.Data;

public partial class _Default : System.Web.UI.Page {
    protected void masterGrid_DataBinding (object sender, EventArgs e) {
        DoSelect(masterDataSource.DataFile);
    }
    private void DoSelect (string connectionString) {
        DataView selectResult = new DataView();
        string selectCommand = "select distinct [CategoryID] from [Products]";
        using (AccessDataSource ds = new AccessDataSource(connectionString, selectCommand)) {
            selectResult = (DataView)ds.Select(DataSourceSelectArguments.Empty);
        }
        ArrayList result = new ArrayList();
        foreach (DataRow row in selectResult.Table.Rows)
            result.Add(row["CategoryID"]);
        Session["SelectResult"] = result;
    }
    protected void masterGrid_DetailRowGetButtonVisibility
    (object sender, ASPxGridViewDetailRowButtonEventArgs e) {
        if (!((ArrayList)Session["SelectResult"]).Contains(e.KeyValue))
            e.ButtonState = GridViewDetailRowButtonState.Hidden;
    }
    protected void detailGrid_BeforePerformDataSelect (object sender, EventArgs e) {
        Session["CategoryID"] = (sender as ASPxGridView).GetMasterRowKeyValue();
    }
}

Imports Microsoft.VisualBasic
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports DevExpress.Web.ASPxGridView
Imports DevExpress.Web.Data
Imports System.Drawing
Imports System.Collections
Imports System.Data

Partial Public Class _Default
    Inherits System.Web.UI.Page
    Protected Sub masterGrid_DataBinding(ByVal sender As Object, ByVal e As EventArgs)
        DoSelect(masterDataSource.DataFile)
    End Sub
    Private Sub DoSelect(ByVal connectionString As String)
        Dim selectResult As New DataView()
        Dim selectCommand As String = "select distinct [CategoryID] from [Products]"
        Using ds As New AccessDataSource(connectionString, selectCommand)
            selectResult = CType(ds.Select(DataSourceSelectArguments.Empty), DataView)
        End Using
        Dim result As New ArrayList()
        For Each row As DataRow In selectResult.Table.Rows
            result.Add(row("CategoryID"))
        Next row
        Session("SelectResult") = result
    End Sub
    Protected Sub masterGrid_DetailRowGetButtonVisibility(ByVal sender As Object, ByVal e As ASPxGridViewDetailRowButtonEventArgs)
        If Not(CType(Session("SelectResult"), ArrayList)).Contains(e.KeyValue) Then
            e.ButtonState = GridViewDetailRowButtonState.Hidden
        End If
    End Sub
    Protected Sub detailGrid_BeforePerformDataSelect(ByVal sender As Object, ByVal e As EventArgs)
        Session("CategoryID") = (TryCast(sender, ASPxGridView)).GetMasterRowKeyValue()
    End Sub
End Class

<%@ Page Language="vb" AutoEventWireup="true" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<%@ Register Assembly="DevExpress.Web.ASPxGridView.v10.1, Version=10.1.12.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxGridView" TagPrefix="dx" %>
<%@ Register Assembly="DevExpress.Web.ASPxEditors.v10.1, Version=10.1.12.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxEditors" 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>How to hide the detail button if the detail grid is empty</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <br />
        <br />
    </div>
    <dx:ASPxGridView ID="mainGrid" runat="server" AutoGenerateColumns="False" DataSourceID="masterDataSource"
        KeyFieldName="CategoryID" OnDataBinding="masterGrid_DataBinding" OnDetailRowGetButtonVisibility="masterGrid_DetailRowGetButtonVisibility">
        <Templates>
            <DetailRow>
                <dx:ASPxGridView ID="detailGrid" runat="server" AutoGenerateColumns="False" DataSourceID="dsDetail"
                    KeyFieldName="ProductID" OnBeforePerformDataSelect="detailGrid_BeforePerformDataSelect"
                    Width="100%">
                    <Styles>
                        <DetailRow HorizontalAlign="Justify">
                        </DetailRow>
                    </Styles>
                    <Columns>
                        <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" VisibleIndex="0">
                            <EditFormSettings Visible="False" />
                        </dx:GridViewDataTextColumn>
                        <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
                        </dx:GridViewDataTextColumn>
                        <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="2">
                        </dx:GridViewDataTextColumn>
                    </Columns>
                </dx:ASPxGridView>
            </DetailRow>
        </Templates>
        <Columns>
            <dx:GridViewDataTextColumn FieldName="CategoryID" ReadOnly="True" VisibleIndex="0">
                <EditFormSettings Visible="False" />
            </dx:GridViewDataTextColumn>
            <dx:GridViewDataTextColumn FieldName="CategoryName" VisibleIndex="1">
            </dx:GridViewDataTextColumn>
            <dx:GridViewDataTextColumn FieldName="Description" VisibleIndex="2">
            </dx:GridViewDataTextColumn>
        </Columns>
        <SettingsDetail ShowDetailRow="True" />
    </dx:ASPxGridView>
    <asp:AccessDataSource ID="dsDetail" runat="server" DataFile="~/App_Data/nwind.mdb"
        SelectCommand="SELECT [ProductID], [ProductName], [CategoryID], [UnitPrice] FROM [Products]  WHERE ([CategoryID] = ?)">
        <SelectParameters>
            <asp:SessionParameter DefaultValue="CategoryID" Name="CategoryID" SessionField="CategoryID"
                Type="Int32" />
        </SelectParameters>
    </asp:AccessDataSource>
    <asp:AccessDataSource ID="masterDataSource" runat="server" DataFile="~/App_Data/nwind.mdb"
        SelectCommand="SELECT * FROM [Categories]"></asp:AccessDataSource>
    </form>
</body>
</html>

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ASPxGridView.DetailRowGetButtonVisibility Event

Declaration

Event Data

Remarks

Example