Calls back to the ASPX page with the specified command.

Syntax

[JavaScript]

FpSpread1.CallBack(cmd, asyncCallBack);

Parameters

cmd

String, the command to post back
See the list of reserved commands below

asyncCallBack

Boolean, whether to allow an asynchronous callback

Reserved Commands

The following pre-defined commands are built into Spread. These are reserved command names; do not use these names for any custom commands that you create, as Spread ignores the custom definition and uses the built-in definition. Not all the commands have corresponding events.

For those commands that correspond with command events in FpSpread, using these commands with the CallBack function basically behaves the same as if you had clicked the appropriate command bar button.

The ChildView command looks like this:

     FpSpread1.CallBack("ChildView,relationname")

where relationname is the name of the relation you are trying to view.

The ExpandView command looks like this:

     FpSpread1.CallBack("ExpandView,rownum")

where rownum is the zero-indexed row number to expand. For example, a rownum of 2 expands the third row of the parent sheet (since row indexes are zero-indexed). If you want to expand a row below the parent sheet level, you have to know the name of the sheet at that level. This code expands the fourth row at the particular level in the hierarchy:

     function DoCallBack() {           var ss = event.spread;           ss.CallBack("ExpandView,3");      }

The Page command looks like this:

     FpSpread1.CallBack("Page,pagenum")

where pagenum is the zero-indexed page number on the active sheet. For example, a pagenum of 2 scrolls to the third page on the active sheet, since the sheets are zero-indexed.

Note: Using the CallBack method when the Spread control fires an event can cause an incorrect state. Try code similar to the following to prevent this:

Custom Commands

If you use a string to define a CallBack with a command that is not a one of the built-in commands, Spread raises the ButtonCommand event for the Spread component and passes in the name of the custom CallBack command as e.CommandName, as shown in this example code.

In JavaScript:

FpSpread1.CallBack("MyCommand", false)

In corresponding server-side code (Visual Basic .NET):

Private Sub FpSpread1_ButtonCommand(ByVal sender As Object, ByVal e As FarPoint.Web.Spread.SpreadCommandEventArgs) Handles FpSpread1.ButtonCommand
If e.CommandName = "MyCommand" Then
FpSpread1.Sheets(0).Cells(0, 0).Text = "My Command Worked"
End If
End Sub

Return Type

None

Examples

This is a sample that contains the method with one of the built-in commands. On the client side, the script that contains the method would look like this:

<script type="text/javascript">
   function SortIt() {
       FpSpread1.CallBack(SortColumn, false);
   }
</script>

This is a sample showing a simple way of programmatically doing an AJAX postback that raises the UpdateCommand event:

<script language="javascript">
  function window.onload() {
    FpSpread1.onDataChanged = DoCallBack;
  }
  function DoCallBack() {
    FpSpread1.UpdatePostbackData();
    FpSpread1.CallBack("Update", true);
  }
</script>