Visual studio 2005 Question TreeView webpart question

[cplsplsprogrammer]

Hello All,

I am trying to build a webpart which using a TreeView. I had build a class to create a tree and load my tree. How can I eliminate calling the constructor when a page does a post back? Is there anyway I can do that? I think because of calling the constructor and building the tree again and again every time a page does a postback it is creating a problem.

I load the basic tree structure on page load and wanted to load the children of those nodes on the fly and so I used the eventhandler but after I catch the event and get the node and try to find the parent of the node it is givining me NULL value but it is showing the depth correctly I think the parent node for only root node will be null. Can anyone tell me if I have enable any feature or anything that I am missing.

Thanks,
Ram

 

[jbenson001]

. How can I eliminate calling the constructor when a page does a post back?

Then constructor of which object?

 

[cplsplsprogrammer]

Hey Benson,

I created a class for building a tree. I load the basic structure of the tree and load the leaf nodes dynamically when the user clicks on the node.

When I try to click on the nodes to view the details of the clicked node in another webpart the tree view webpart is doing a post back and it loads the tree again. How can I eliminate that? I cant use the IsPostBack propert in my class.

Thanks,
Ram

 

[jbenson001]

Where are you calling the class to populate your tree view initially? I would assume the page load, correct?

 

[cplsplsprogrammer]

Benson,
This is how I call my webpart. TreeDisplay in zonetemplate is my class which had all the code to create a tree and handle all the tree events.
-- Ram


<form id="form1" runat="server">
<div>
<asp:webpartmanager id="WebPartManager1" runat="server">
<StaticConnections>
<asp:WebPartConnection id="con1" ProviderID="provider1"
ConsumerID="consumer1"
ConsumerConnectionPointID="Connpoint1">
</asp:WebPartConnection>
</StaticConnections>
</asp:webpartmanager>
<asp:webpartzone id="WebPartZone1" runat="server">
<zoneTemplate>
<ifield:TreeDisplay runat="Server"
ID="provider1" Title="Provider" />
<ifield:fieldconsumerwebpart2 runat="Server"
ID="consumer1" Title="Consumer"/>
</zoneTemplate>
</asp:webpartzone>
</div>
</form>

 

[philhege]

Do you have any code-behind? I'd wrap the piece that constructs the tree in a conditional, like

If Not IsPostback Then
...

In VS2003 help, this is at

ms-help://MS.VSCC.2003/MS.MSDNQTR.2005OCT.1033/cpref/html/frlrfSystemWebUIPageClassIsPostBackTopic.htm

HTH,

Phil Hegedusich
Senior Programmer/Analyst
IIMAK

http://www.iimak.com

-----------
I'll have the roast duck with the mango salsa.

 

[cplsplsprogrammer]

Hello Phil,

No, I dont have a code behind. It is a webpart so all I can do is call the webpart. As I dont have code behind I cannot use NotIsPostback. How do I access the link that you have sent me? Is that from your msdn downloaded on your machine?

-- Ram

 

[philhege]

Yeah, it's local, but you should be able to find the help on MSDN.

And.... you should be able to run code-behind in a Web part, given registration in the GAC. At least I believe that's how the SPS cookie crumbles.

Phil Hegedusich
Senior Programmer/Analyst
IIMAK

http://www.iimak.com

-----------
I'll have the roast duck with the mango salsa.