Using sepirated Dataviews with one Datatable for filling two combobox

Question

I have one Datatable and I have two Dataviews, I wanted to use each Dataview to fill a Combobox as next code:

        Dim xDv_Parents As DataView = MyVar_Dt_AllAccounts.DefaultView
        xDv_Parents.RowFilter = "AccType='Main'"
        Call xCLS.MyCodes_CboFill_Dv(Me.CboAccParent, "AccName", "AccID", xDv_Parents)

        Dim xDv_Final As DataView = MyVar_Dt_AllAccounts.DefaultView
        xDv_Final.RowFilter = "AccType='Final'"
        Call xCLS.MyCodes_CboFill_Dv(Me.CboAccFinal, "AccName", "AccID", xDv_Final)

but when I debug the app it gives me the same content in two Comboboxs according the last Dataview the named is (xDv_Final).

I tried to use one Dataview with different row filter but it wasn't a success. what's the problem exactly here please!?

Caius Jard · Accepted Answer · 2020-07-11T09:51:03.070

It's because you reused the same view for both comboboxes. All you did was establish new variables pointing to the same object in memory. First you had this:

Then you made another variable, same object:

    Dim xDv_Parents As DataView = MyVar_Dt_AllAccounts.DefaultView

Then you set a rowfilter:

    xDv_Parents.RowFilter = "AccType='Main'"

Then you told one combo to use it, so now you have a combo pointing to it too:

    Call xCLS.MyCodes_CboFill_Dv(Me.CboAccParent, "AccName", "AccID", xDv_Parents)

Then you made another variable, also pointing to it, and overwrote the rowfilter you just set:

    Dim xDv_Final As DataView = MyVar_Dt_AllAccounts.DefaultView
    xDv_Final.RowFilter = "AccType='Final'"

Finally you attached another combo to the same view:

    Call xCLS.MyCodes_CboFill_Dv(Me.CboAccFinal, "AccName", "AccID", xDv_Final)

This is just how variables in .net programming languages work. Unless you use New you're just attaching new variables to existing object instances

What you should have done was:

    Dim xDv_Parents = new DataView(MyVar_Dt_AllAccounts)
    xDv_Parents.RowFilter = "AccType='Main'"
    xCLS.MyCodes_CboFill_Dv(Me.CboAccParent, "AccName", "AccID", xDv_Parents)

    Dim xDv_Final = New DataView(MyVar_Dt_AllAccounts.DefaultView)
    xDv_Final.RowFilter = "AccType='Final'"
    xCLS.MyCodes_CboFill_Dv(Me.CboAccFinal, "AccName", "AccID", xDv_Final)

it's a great answer, why you used the declaration at the first without ".DefaultView"? — Hamada, Jul 11 '20 at 14:38
and if you can tell which solution is better, your answer or my answer and why? — Hamada, Jul 11 '20 at 14:44

score 1 · Answer 2 · answered Jul 11 '20 at 01:22

I found a solution, but if anybody has another solution please share it with us, I used ".ToTable" at last of the data view.

    Dim xDv_Parents As DataView = MyVar_Dt_AllAccounts.DefaultView
    xDv_Parents.RowFilter = "AccType='Main'"
    Call xCLS.MyCodes_CboFill_Dv(Me.CboAccParent, "AccName", "AccID", xDv_Parents.ToTable)

    Dim xDv_Final As DataView = MyVar_Dt_AllAccounts.DefaultView
    xDv_Final.RowFilter = "AccType='Final'"
    Call xCLS.MyCodes_CboFill_Dv(Me.CboAccFinal, "AccName", "AccID", xDv_Final.ToTable)

and I used the next code:

 Dim xdv As DataView = MyVar_Dt_AllAccounts.DefaultView
 xdv.RowFilter = "AccType='Main'"
 Call xCLS.MyCodes_CboFill_Dv(Me.CboAccParent, "AccName", "AccID", xdv.ToTable)

xdv.RowFilter = "AccType='Final'"
Call xCLS.MyCodes_CboFill_Dv(Me.CboAccFinal, "AccName", "AccID", xdv.ToTable)

can anybody give us any comment about which solution is better and what the difference?

Using sepirated Dataviews with one Datatable for filling two combobox

2 Answers2