To invoke this mode, just call the client-side editRow method with parameter the ID (key) of the row to be edited inline. A typical way to do it is to make a row editable inline on click, using the OnClientRowSelect client-side event of the grid. Example:

<trirand:JQGrid ID="JQGrid1" runat="server" Width="600px" ShowToolBar="True" OnRowEditing="JQGrid1_RowEditing">         
   <Columns>
      <trirand:JQGridColumn DataField="EmployeeID" Editable="false" PrimaryKey="true" Width="50"/>                
      <trirand:JQGridColumn DataField="FirstName" Editable="true" />
      <trirand:JQGridColumn DataField="LastName" Editable="true" />
      <trirand:JQGridColumn DataField="BirthDate" Editable="true" DataFormatString="{0:yyyy-MM-dd}" />
   </Columns>
   <ClientSideEvents OnClientRowSelect="editRow" />
</trirand:JQGrid>

     <script type="text/javascript">
       
           var lastSelection;

           function editRow(id) {
               if (id && id !== lastSelection) {
                   var grid = jQuery("#<%= JQGrid1.ClientID %>");
                   grid.restoreRow(lastSelection);
                   grid.editRow(id, true);
                   lastSelection = id;
               }
           }
      </script>

When end-users finish editing of the row in inline edit mode, the server-side RowEditing event is fired and you can proceed with edit logic as described in the RowEditing / RowEdited section of the help.