How to find the number of expanded/collapsed master rows and grouped rows in a DevExpress GridView?

问题

I am currently using DevExpress 10.2 within Visual Studio 2010. In a previous question I was trying to print the current user view of a DevExpress GridControl with the user's choice of expanded or collapsed master rows and/or group sections. I was told this was not possible at this time. I have now decided to use the following code:

gvPOinvoiceBanded.OptionsPrint.ExpandAllGroups = False
gvPOinvoiceBanded.OptionsPrint.ExpandAllDetails = False

when I want it to be completely collapsed while printing as by default these are set to true.

I was just wondering if there is someway to check either the total number of expanded master rows or the total number of collapsed master rows. I would also like to do the same thing for the groups as you can have the groups expanded while the master rows are not.

回答1:

You can get the number of expanded group rows using a loop like this:

    Dim ExpandedGroupCount As Integer = 0
    Dim Handle As Integer = -1  'group rows have negative row handles
    Do Until GridView1.GetRow(Handle) Is Nothing
        If GridView1.GetRowExpanded(Handle) Then
            ExpandedGroupCount += 1
        End If
        Handle -= 1
    Loop
    'Do whatever with expanded group count
    MsgBox(String.Format("Number of Expanded Group Rows: {0}{2}Number of Group Rows: {1}",
          ExpandedGroupCount, Math.Abs(Handle + 1), Environment.NewLine))

Similarly, you can do this to get the count of expanded master rows:

    Handle = 0
    Dim ExpandedMasterRowCount As Integer = 0
    Do Until GridView1.GetRow(Handle) Is Nothing
        If GridView1.IsMasterRow(Handle) Then
            If GridView1.GetMasterRowExpanded(Handle) Then
                ExpandedMasterRowCount += 1
            End If
        End If
        Handle += 1
    Loop
    MsgBox(String.Format("Number of Expanded Master Rows: {0}", ExpandedMasterRowCount))

Of course, if you are only checking so that you can see if you need to set the collapse this probably isn't worth the effort. There is no direct property that provides the counts you are looking for.

You could also probably use the events that fire when rows are collapsed and expanded to track the count as it changes. You have to be careful with that though because the event only fires once when expand or collapse all happens. So if you go with that method be sure to check the rowHandle in the event arguments parameter for GridControl.InvalidRowHandle. That is the value used in the case of collapse or expand all.

来源：https://stackoverflow.com/questions/8916755/how-to-find-the-number-of-expanded-collapsed-master-rows-and-grouped-rows-in-a-d