[CLOSED] How to call the plug-in command event

[tobros]

I have a gridpanel plugin is as follows:

<ext:GridPanel runat="server" ID="gridPanelZZ" Region="Center" AutoScroll="true">

 <Plugins>
                            <ext:RowExpander runat="server" ExpandOnDblClick="true" SingleExpand="true" ExpandOnEnter="true" IsDynamic="true">
                                <Loader runat="server" DirectMethod="App.direct.GetGrid" Mode="Component">
                                    <LoadMask ShowMask="true" />
                                    <Params>
                                        <ext:Parameter Name="Month" Value="this.record.data.Month" Mode="Raw" />
                                    </Params>
                                </Loader>
                            </ext:RowExpander>
                        </Plugins>

There is also a command as follows:

 <ext:CommandColumn runat="server" Width="60">
                                    <Commands>
                                        <ext:GridCommand Icon="SectionExpanded" CommandName="Expand">
                                        </ext:GridCommand>
                                    </Commands>
                                    <Listeners>
                                        <Command Handler="" />
                                    </Listeners>
                                </ext:CommandColumn>

command column how to trigger plug-in??? how to write command handler???