How to set controls in a DataGrid's ItemDateBound without a costly conversion?

[Daniel Walzenbach]

Hi,



I want to display a Label in a DataGrid according to some condition. I therefore check whether the condition is true in the ItemDateBound EventHandler of the DataGrid. Unfortunately the conversion is extremely costly in performance. Does anybody know how I could set the label (of the whole content of the TableCell) to .Visible = False without converting e.Item.Controls (2) to a System.Web.UI.W ebControls.Labe l?





Private Sub DataGrid_ItemDa taBound(ByVal sender As System.Object, ByVal e As System.Web.UI.W ebControls.Data GridItemEventAr gs) Handles DataGrid.ItemDa taBound



If e.Item.ItemType = ListItemType.It em Or e.Item.ItemType = ListItemType.Al ternatingItem Or e.Item.ItemType = ListItemType.Se lectedItem Then

Dim button As LinkButton = CType(e.Item.Ce lls(0).Controls (0), LinkButton)

Dim col As Integer

For col = 0 To e.Item.Cells.Co unt - 1

e.Item.Cells(co l).Attributes(" onClick") = Page.GetPostBac kClientHyperlin k(button, col.ToString)

Next



' This conversion is EXTREMELY costly.

If CInt(CType(e.It em.DataItem, System.data.Dat aRowView).Item( "ID")) <> myUser.ID Then

CType(e.Item.Co ntrols(2).Contr ols(1), System.Web.UI.W ebControls.Labe l).Visible = False

End If



End If



End Sub



Thanks a lot in advance!



Daniel

[Martin]

It should refresh in the normal build process, but I can't swear to it.

Two alternatives are:
*Rebuild* project/solution
or
right click xsd file in solution explorer, click "Run Custom Tool"

Martin

"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:uu******** ******@tk2msftn gp13.phx.gbl...
Indeed, one cast won't make any big difference but nevertheless.

I try to avoid using typed dataset since you are completely lost when your datastructure changes (I have not found any way to "refresh" a typed dataset when structure changes which leaves me in the position to make the changes by my own). I suppose, I am going to create the hyperlink on the server, eliminate the click event for the first visible column and place the hyperlink right in there. I assume this will work with satisfying performance :-)



Thanks again for your incitation.



Daniel

"Martin" <x@y.z> schrieb im Newsbeitrag news:uo******** ******@TK2MSFTN GP11.phx.gbl...

Okay,

Have you tried a typed dataset with the display/no display info in there? I don't suppose the cast saving made any time difference(?)

Martin
"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:O0******** ******@tk2msftn gp13.phx.gbl...
Hi Martin,



Thanks for the tip using the visible property of the control instead of the label. This saves one cast :-)



Regarding your question why I cast from e.Item.Controls (2).Controls(1) , I pasted a part of my DataGrid (updated as you/Steve suggested).



<Columns>

<asp:ButtonColu mn Visible="False" CommandName="Se lect"></asp:ButtonColum n>

<asp:BoundColum n Visible="False" DataField="Vorg ang_OIDVorgang" ></asp:BoundColumn >

<asp:TemplateCo lumn ItemStyle-Width="60px" ItemStyle-HorizontalAlign ="Center">

<ItemTemplate >

<asp:Label CssClass="Butto nInGrid" text=" Abteilungssicht " Runat="server" ID="LabelAbteil ungssicht" Visible='<%# Abteilungssicht Anzeigen(DataBi nder.Eval(Conta iner.DataItem, "Vorgang_IDKost enstelle")) %>'></asp:Label>

</ItemTemplate>

</asp:TemplateCol umn>



As you can see there are two hidden columns (which explains e.Item.Controls (2)) plus a label in the third column. Therefore e.Item.Controls (2).Controls(0) is a System.Web.UI.L iteralControl and that's the reason why I have to cast e.Item.Controls (2).Controls(1) witch is the actual label.



Daniel



"Martin" <x@y.z> schrieb im Newsbeitrag news:uY******** ******@tk2msftn gp13.phx.gbl...
Hi Daniel,

I see.

I presume you have a dataset to populate the datagrid. I would try adding a field to the dataset to determine if the edit can be done, and using that as the datasource for the first column. Might not be any faster though - you'd have to try it. This solution depends on how your dataset is created - once for every user, or on a per user basis.

Also, you would probably find some performance improvement if you used a typed dataset - you wouldn't have to index your row by column name at runtime.

However like Steven says, it's probably the effort of getting the sub controls in the datagrid that is doing the damage - test this by sticking some dummy statement in place of CType(e.Item.Co ntrols(2).Contr ols(1), System.Web.UI.W ebControls.Labe l).Visible = False
As a minor point, in the above statement, you shouldn't have to bother doing the CType to Label, as the Control base class also has the Visible property.
From that statement it looks like you have other sub controls in that cell of the datagrid. Why do you have Controls(2).Con trols(1)? Can you simplfiy that?

Interested to hear how it goes.
Martin
"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:uF******** *******@tk2msft ngp13.phx.gbl.. .
Martin,



I have a DataGrid which displays orders users have made.



Edit | OrderID | Order Description | Order ...

--------|---------------|-----------------------|--------------------

Edit | 1 | Some Order |

| 2 | Another Order |

Edit | 3 | Third Order |

Edit | 4 | Forth Order |



Since I want everybody to be able to see (in a read-only fashion) all orders I modified a DataGrid in that way that a click on the Columns "OrderID", "Order Description", "Order ..." redirects the actual user to another page where he/she can view the order details. If though the logged in user is the same user as the one who created an order I want him to be able to click on the first column "Edit" where he gets redirected to another page where he/she can edit his order. As the logged in user should see which order he can edit I want to display a label in the first column reflecting his/hers possibilities (In this example the user could edit all orders but "Another Order"). Fact is, that everything works perfectly well as it should, but the performance is not as want it to be.



Thanks for your help! I hope this description helps you better to understand what I want to do.



Daniel
"Martin" <x@y.z> schrieb im Newsbeitrag news:ur******** ******@TK2MSFTN GP12.phx.gbl...
Looks like you would end up displaying the ID if it wasn't *your* userID - so you would display other user ID?

What happens to other fields in this row? If the whole row should be affected, a filter on the dataview might be the way to go - probably requiring a mod to your data source.

A bit more info on the wider problem may reveal a better solution.

Martin

"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:uu******** ******@tk2msftn gp13.phx.gbl...
Hi,



I want to display a Label in a DataGrid according to some condition. I therefore check whether the condition is true in the ItemDateBound EventHandler of the DataGrid. Unfortunately the conversion is extremely costly in performance. Does anybody know how I could set the label (of the whole content of the TableCell) to .Visible = False without converting e.Item.Controls (2) to a System.Web.UI.W ebControls.Labe l?





Private Sub DataGrid_ItemDa taBound(ByVal sender As System.Object, ByVal e As System.Web.UI.W ebControls.Data GridItemEventAr gs) Handles DataGrid.ItemDa taBound



If e.Item.ItemType = ListItemType.It em Or e.Item.ItemType = ListItemType.Al ternatingItem Or e.Item.ItemType = ListItemType.Se lectedItem Then

Dim button As LinkButton = CType(e.Item.Ce lls(0).Controls (0), LinkButton)

Dim col As Integer

For col = 0 To e.Item.Cells.Co unt - 1

e.Item.Cells(co l).Attributes(" onClick") = Page.GetPostBac kClientHyperlin k(button, col.ToString)

Next



' This conversion is EXTREMELY costly.

If CInt(CType(e.It em.DataItem, System.data.Dat aRowView).Item( "ID")) <> myUser.ID Then

CType(e.Item.Co ntrols(2).Contr ols(1), System.Web.UI.W ebControls.Labe l).Visible = False

End If



End If



End Sub



Thanks a lot in advance!



Daniel

[Daniel Walzenbach]

Thank you Martin,

I will give it a try.

Daniel

"Martin" <x@y.z> schrieb im Newsbeitrag news:%2******** ********@TK2MSF TNGP12.phx.gbl. ..
It should refresh in the normal build process, but I can't swear to it.

Two alternatives are:
*Rebuild* project/solution
or
right click xsd file in solution explorer, click "Run Custom Tool"

Martin

"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:uu******** ******@tk2msftn gp13.phx.gbl...
Indeed, one cast won't make any big difference but nevertheless.

I try to avoid using typed dataset since you are completely lost when your datastructure changes (I have not found any way to "refresh" a typed dataset when structure changes which leaves me in the position to make the changes by my own). I suppose, I am going to create the hyperlink on the server, eliminate the click event for the first visible column and place the hyperlink right in there. I assume this will work with satisfying performance :-)



Thanks again for your incitation.



Daniel

"Martin" <x@y.z> schrieb im Newsbeitrag news:uo******** ******@TK2MSFTN GP11.phx.gbl...

Okay,

Have you tried a typed dataset with the display/no display info in there? I don't suppose the cast saving made any time difference(?)

Martin
"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:O0******** ******@tk2msftn gp13.phx.gbl...
Hi Martin,



Thanks for the tip using the visible property of the control instead of the label. This saves one cast :-)



Regarding your question why I cast from e.Item.Controls (2).Controls(1) , I pasted a part of my DataGrid (updated as you/Steve suggested).



<Columns>

<asp:ButtonColu mn Visible="False" CommandName="Se lect"></asp:ButtonColum n>

<asp:BoundColum n Visible="False" DataField="Vorg ang_OIDVorgang" ></asp:BoundColumn >

<asp:TemplateCo lumn ItemStyle-Width="60px" ItemStyle-HorizontalAlign ="Center">

<ItemTemplate >

<asp:Label CssClass="Butto nInGrid" text=" Abteilungssicht " Runat="server" ID="LabelAbteil ungssicht" Visible='<%# Abteilungssicht Anzeigen(DataBi nder.Eval(Conta iner.DataItem, "Vorgang_IDKost enstelle")) %>'></asp:Label>

</ItemTemplate>

</asp:TemplateCol umn>



As you can see there are two hidden columns (which explains e.Item.Controls (2)) plus a label in the third column. Therefore e.Item.Controls (2).Controls(0) is a System.Web.UI.L iteralControl and that's the reason why I have to cast e.Item.Controls (2).Controls(1) witch is the actual label.



Daniel



"Martin" <x@y.z> schrieb im Newsbeitrag news:uY******** ******@tk2msftn gp13.phx.gbl...
Hi Daniel,

I see.

I presume you have a dataset to populate the datagrid. I would try adding a field to the dataset to determine if the edit can be done, and using that as the datasource for the first column. Might not be any faster though - you'd have to try it. This solution depends on how your dataset is created - once for every user, or on a per user basis.

Also, you would probably find some performance improvement if you used a typed dataset - you wouldn't have to index your row by column name at runtime.

However like Steven says, it's probably the effort of getting the sub controls in the datagrid that is doing the damage - test this by sticking some dummy statement in place of CType(e.Item.Co ntrols(2).Contr ols(1), System.Web.UI.W ebControls.Labe l).Visible = False
As a minor point, in the above statement, you shouldn't have to bother doing the CType to Label, as the Control base class also has the Visible property.
From that statement it looks like you have other sub controls in that cell of the datagrid. Why do you have Controls(2).Con trols(1)? Can you simplfiy that?

Interested to hear how it goes.
Martin
"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:uF******** *******@tk2msft ngp13.phx.gbl.. .
Martin,



I have a DataGrid which displays orders users have made.



Edit | OrderID | Order Description | Order ...

--------|---------------|-----------------------|--------------------

Edit | 1 | Some Order |

| 2 | Another Order |

Edit | 3 | Third Order |

Edit | 4 | Forth Order |



Since I want everybody to be able to see (in a read-only fashion) all orders I modified a DataGrid in that way that a click on the Columns "OrderID", "Order Description", "Order ..." redirects the actual user to another page where he/she can view the order details. If though the logged in user is the same user as the one who created an order I want him to be able to click on the first column "Edit" where he gets redirected to another page where he/she can edit his order. As the logged in user should see which order he can edit I want to display a label in the first column reflecting his/hers possibilities (In this example the user could edit all orders but "Another Order"). Fact is, that everything works perfectly well as it should, but the performance is not as want it to be.



Thanks for your help! I hope this description helps you better to understand what I want to do.



Daniel
"Martin" <x@y.z> schrieb im Newsbeitrag news:ur******** ******@TK2MSFTN GP12.phx.gbl...
Looks like you would end up displaying the ID if it wasn't *your* userID - so you would display other user ID?

What happens to other fields in this row? If the whole row should be affected, a filter on the dataview might be the way to go - probably requiring a mod to your data source.

A bit more info on the wider problem may reveal a better solution.

Martin

"Daniel Walzenbach" <da************ **********@freu denberg.de> wrote in message news:uu******** ******@tk2msftn gp13.phx.gbl...
Hi,



I want to display a Label in a DataGrid according to some condition. I therefore check whether the condition is true in the ItemDateBound EventHandler of the DataGrid. Unfortunately the conversion is extremely costly in performance. Does anybody know how I could set the label (of the whole content of the TableCell) to .Visible = False without converting e.Item.Controls (2) to a System.Web.UI.W ebControls.Labe l?





Private Sub DataGrid_ItemDa taBound(ByVal sender As System.Object, ByVal e As System.Web.UI.W ebControls.Data GridItemEventAr gs) Handles DataGrid.ItemDa taBound



If e.Item.ItemType = ListItemType.It em Or e.Item.ItemType = ListItemType.Al ternatingItem Or e.Item.ItemType = ListItemType.Se lectedItem Then

Dim button As LinkButton = CType(e.Item.Ce lls(0).Controls (0), LinkButton)

Dim col As Integer

For col = 0 To e.Item.Cells.Co unt - 1

e.Item.Cells(co l).Attributes(" onClick") = Page.GetPostBac kClientHyperlin k(button, col.ToString)

Next



' This conversion is EXTREMELY costly.

If CInt(CType(e.It em.DataItem, System.data.Dat aRowView).Item( "ID")) <> myUser.ID Then

CType(e.Item.Co ntrols(2).Contr ols(1), System.Web.UI.W ebControls.Labe l).Visible = False

End If



End If



End Sub



Thanks a lot in advance!



Daniel

[Yan-Hong Huang[MSFT]]

Hello Diniel,

I was reviewing the thread. It seems that the question is OK now. If you have any more concerns on this issue, please feel free to post here and
we will follow up.

Thanks very much.

Best regards,
Yanhong Huang
Microsoft Community Support

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