Displaying ASPxGridView row index number

You can achieve this through two way:

Method 1

Step 1. Add ASPxGridView on your page:

<dx:ASPxGridView ID="grvTest" AutoGenerateColumns="False" runat="server"
DataSourceID="SqlDataSource1" onhtmlrowprepared="grvTest_HtmlRowPrepared"
onhtmlrowcreated="grvTest_HtmlRowCreated">
<Columns>
<dx:GridViewDataTextColumn Caption="RowID" Name="colRowID" VisibleIndex="0"
Width="20px">
<DataItemTemplate>
<dx:ASPxLabel ID="lblRowID" runat="server" Text="lablel">
</dx:ASPxLabel>
</DataItemTemplate>
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="User Name" FieldName="UserName"
Name="colUserName" VisibleIndex="1" Width="100px">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="Password" FieldName="Password"
Name="colPassword" VisibleIndex="2" Width="30px">
</dx:GridViewDataTextColumn>
<dx:GridViewDataTextColumn Caption="Role" FieldName="Role" Name="colRole"
VisibleIndex="3" Width="30px">
</dx:GridViewDataTextColumn>
</Columns>
</dx:ASPxGridView>

Step 2: Add following ASPxGridView Event code snippet to your code – behind file (.cs)

protected void grvTest_HtmlRowCreated(object sender, ASPxGridViewTableRowEventArgs e)
{
if (e.RowType != GridViewRowType.Data) return;

ASPxLabel label = grvTest.FindRowCellTemplateControl(e.VisibleIndex, null, "lblRowID") as ASPxLabel;
label.Text = (e.VisibleIndex + 1).ToString();
}

Method 2

The another way to do it is this one in the Columns section of your GridView control:

<dx:ASPxGridView ID="grvTest" AutoGenerateColumns="False" runat="server"
DataSourceID="SqlDataSource1" >
<Columns>
<dx:GridViewDataTextColumn Caption="RowID" Name="colRowID" VisibleIndex="0"
Width="20px">
<DataItemTemplate>
<dx:ASPxLabel ID="lblRowID" runat="server" Text='<%# Container.ItemIndex + 1 %>'>
</dx:ASPxLabel>
</DataItemTemplate>
</dx:GridViewDataTextColumn>