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Many customers are facing such scenes, and they hope to retain the election status of the end user after the application of sorting or filtering. Under normal circumstances, when we choose any line, we apply or filter to cause the selection state after returning. This blog will discuss how we do it to keep the selection state after sorting and filtering.

Step1: willGridViewBind to a data table

First of all, we need to bind GridView to a data table, such as the Categories table from the Northwind database. Since we are using the server selection, we needAutoGenerateSelectButtonProperties are set to “true”, and then “ClientSelectionMode“Properties are set to” None “. Otherwise, we will have two options: client and server.

In addition, we need to set upAllowSortingandShowFilterProperties are “true” for allowinggridviewPerform sort or filtering. The following is the source code of the .aspx page:

<wijmo:C1GridView ID="C1GridView1" runat="server" AllowSorting="True" ClientSelectionMode="None"

AutogenerateColumns="False" AutoGenerateSelectButton="True"

DataKeyNames="CategoryID" DataSourceID="AccessDataSource1"

ShowFooter="False" ShowFilter="True">

<Columns>

<wijmo:C1BoundField DataField="CategoryID" HeaderText="CategoryID"

ReadOnly="True" SortExpression="CategoryID">

</wijmo:C1BoundField>

<wijmo:C1BoundField DataField="CategoryName" HeaderText="CategoryName"

SortExpression="CategoryName">

</wijmo:C1BoundField>

<wijmo:C1BoundField DataField="Description" HeaderText="Description"

SortExpression="Description">

</wijmo:C1BoundField>

<wijmo:C1BoundField DataField="Picture" HeaderText="Picture"

SortExpression="Picture">

</wijmo:C1BoundField>

<wijmo:C1BoundField DataField="UserName" HeaderText="UserName"

SortExpression="UserName">

</wijmo:C1BoundField>

</Columns>

</wijmo:C1GridView>

<asp:AccessDataSource ID="AccessDataSource1" runat="server"

DataFile="~/App_Data/C1NWind.mdb"

SelectCommand="SELECT * FROM [Categories]">

</asp:AccessDataSource>

Step2：Save the selected line

We need to be in one

TheViewStateobject saves the selected data key value so that we can use it to set the selection again. So we need to handleSelectedIndexChangedevent. The code sheet used in this incident is as follows:

Protected Sub C1GridView1_SelectedIndexChanged(sender As Object, e As System.EventArgs) Handles C1GridView1.SelectedIndexChanged

'Save the data key value of the selected data row

If (Not C1GridView1.SelectedIndex = -1) Then

ViewState("SelectedValue") = C1GridView1.SelectedValue

End If

End Sub

Step3: Reset the selected line index

We need to be completed before sorting or filtering, and re -executing the selection action.gridviewSelectedIndexProperties. This job can be hereSortingor

TheFilteringIncident is completed through the following code films:

Protected Sub C1GridView1_Sorting(sender As Object, e As C1.Web.Wijmo.Controls.C1GridView.C1GridViewSortEventArgs) Handles C1GridView1.Sorting

'Reset selection index

C1GridView1.SelectedIndex = -1

End Sub

Protected Sub C1GridView1_Filtering(sender As Object, e As C1.Web.Wijmo.Controls.C1GridView.C1GridViewFilterEventArgs) Handles C1GridView1.Filtering

'Reset selection index

C1GridView1.SelectedIndex = -1

End Sub

Step4: Re -selected the line

gridviewwill be re -binded when returning (due to the execution of sorting or filtering), and we need to deal withDataBoundEvent to redesigned the selection. Here, we should check whether the original selected row is visible, and then re -select it through the ViewState object. The code sheet is shown below:

Protected Sub C1GridView1_DataBound(sender As Object, e As System.EventArgs) Handles C1GridView1.DataBound

Dim Row As C1GridViewRow

Dim SelectedValue As String = ViewState("SelectedValue")

If SelectedValue Is Nothing Then

Return

End If

'Check whether the selected row is visible and select it again.

For Each Row In C1GridView1.Rows

Dim KeyValue As String = C1GridView1.DataKeys(Row.RowIndex).Value

If (KeyValue = SelectedValue) Then

C1GridView1.SelectedIndex = Row.RowIndex

End If

Next

End Sub

Please refer to the complete example in the attachment.

download example

wijmo download, please enterStudio for asp.net wijmo 2012 V1 is officially released (2012.03.22 update)!