EXPaspxgridview开发服务器端事件得到文本框中选定行的详细信息

<dx:ASPxGridView ID="dxGVUser" runat="server" AutoGenerateColumns="False"

                                                                                        ClientIDMode="AutoID" EnableCallBacks="False" KeyFieldName="UserId"

                                                                                        OnSelectionChanged="dxGVUser_SelectionChanged" Width="700px">

                                                                                        <Columns>

                                                                                            <dx:GridViewCommandColumn ShowInCustomizationForm="True" VisibleIndex="0">

                                                                                            </dx:GridViewCommandColumn>

                                                                                            <dx:GridViewDataTextColumn FieldName="UserId" Name="User Id"

                                                                                                ShowInCustomizationForm="True" VisibleIndex="2">

                                                                                            </dx:GridViewDataTextColumn>

                                                                                            <dx:GridViewDataTextColumn FieldName="UserName" Name="User Name"

                                                                                                ShowInCustomizationForm="True" VisibleIndex="3">

                                                                                            </dx:GridViewDataTextColumn>

                                                                                            <dx:GridViewDataTextColumn FieldName="FirstName" Name="First Name"

                                                                                                ShowInCustomizationForm="True" VisibleIndex="4">

                                                                                            </dx:GridViewDataTextColumn>

                                                                                            <dx:GridViewDataTextColumn Caption="Last Name" FieldName="LastName"

                                                                                                Name="Last Name" ShowInCustomizationForm="True" VisibleIndex="5">

                                                                                            </dx:GridViewDataTextColumn>

                                                                                            <dx:GridViewDataTextColumn Caption="Middle Name" FieldName="MiddleName"

                                                                                                Name="Middle Name" ShowInCustomizationForm="True" VisibleIndex="6">

                                                                                            </dx:GridViewDataTextColumn>

                                                                                        </Columns>

                                                                                        <SettingsBehavior AllowFocusedRow="True" AllowSelectByRowClick="True"

                                                                                            AllowSelectSingleRowOnly="True" ProcessSelectionChangedOnServer="True" />

                                                                                    </dx:ASPxGridView>

 

<asp:textbox id="txtUserName" runat="server" width="180px" xmlns:asp="#unknown"></asp:textbox>

 



 

protected void dxGVUser_SelectionChanged(object sender, EventArgs e)

       {

 



           txtUserName.Text = dxGVUser.GetSelectedFieldValues("UserName")[0].ToString();

 



       }