Adding a treeview node index to a querystring 1

[mrathi]

Hi There.

I have a treeview that i am population with data from a database.
Each treenode will have a dirrerent navigateUl assigned to it and the tree has multiple levels.

Basically i understand that the index structure of the tree works like 1.0.3 which will mean that i have the second node -> first node -> fourth node selected.

What i want to know is how do i add a section onto the navigateurl so that when i go to a different page the expanded nodes will still be expanded.
ex page2.aspx?s=1.0.3

Thanks a million

 

[ca8msm]

Where and how do you populate the NavigateURL so that it knows to go to Page2.aspx?

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[mrathi]

I don't, that is what I want to know. So far I am populating my treeview from several tables from a database. When I said navigate url, I meant that by clicking on any node in the treeview, I want to open a page specific to the selected node.

Thanks for your reply.

 

[ca8msm]

OK - I haven't used the treeview control myself yet so I'm just taking a few guesses here.

Could you add an "onclick" attribute (or if there is something similar to navigateURL) to each item when it is created? - is there a ItemCreated method or anything like that?

If not I'll have to have a look into using the control myself (probably should do that anyway!).

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[mrathi]

There is a selectedIndexChange event for the treeview control, but I still don't know how to accomplish what I am trying to..

Thanks

 

[ca8msm]

OK - I've just downloaded the controls.

I notice that there is a NavigateURL for each node - maybe this could be set in the PreRender method (probably not the recommended way but as I've just set it up myself I haven;t had time to check it out properly yet).

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[ca8msm]

Actually could you post your code of how you bind the treeview to the data as there appears to be several ways this may be possible.

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[mrathi]

I populate my dataset and then using the dataset I populate my treeview.

For Each rowAuthor In ds.Tables("Authors").Rows
nodeAuthor = New TreeNode
nodeAuthor.Text = rowAuthor("au_lname") & ", " _
& rowAuthor("au_fname")
TreeView1.Nodes.Add(nodeAuthor)
For Each rowTitle In rowAuthor.GetChildRows("AuthorTitle")
nodeTitle = New TreeNode
nodeTitle.Text = rowTitle("Title")
nodeAuthor.Nodes.Add(nodeTitle)
Next
Next

Thanks

 

[mrathi]

Thanks for all the responses. I figured it out. It was not that bad.

Thanks

 

[mrathi]

Oops, I figured out how to make the nodes hyperlink and how to transfer values of the nodes in querystring, however, I am still stuck at my initai question.

How to keep the status of the treeview on the new page. Also, I want to know if I should make the database connection to populate the tree on every page, or is there a better way.

Thanks

 

[ca8msm]

Thanks for all the responses. I figured it out. It was not that bad.

I take it you did something like:

nodeTitle = New TreeNode
nodeTitle.Text = rowTitle("Title")
nodeTitle.NavigateURL = "AnotherPage.aspx?SelectedItem=" & nodeTitle.ID
nodeAuthor.Nodes.Add(nodeTitle)

Is this correct?

If so, then on "AnotherPage.aspx" you just have to expand the node that is passed through by the "SelectedItem" querystring.

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[mrathi]

Yes, that is how I am doing. However on another page I need the rowTitle("Title") and that is what I am passing. If a user clicks on the fourth level on the treeview, in the querystring, I pass all the four values(in text, not node).

Thanks

 

[mrathi]

I am sorry, I still haven't figured out the follwoing:

What i want to know is how do i add a section onto the navigateurl so that when i go to a different page the expanded nodes will still be expanded.
ex page2.aspx?s=1.0.3

Thanks

 

[vinidel]

mrathi,

I am wondering if you got the solution to your problem.
I am also haveing the identical problem, how to keep my tree view nodes expanded when user click on the tree node to navigate to different page.

I would appreciate if you share your solution.


Thanks

 

[mrathi]

I am sorry, I did not get any solution so far. I got busy with some other stuff. It looks like it will be a tough task to figure that out.

Good Luck. By the way, if you get a solution, will you please let me know.

Thanks

 

[ca8msm]

You would simply use the querystring value like I suggested in my last post...

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[greggiepoo]

Hi mrathi and others!

I've had the same problem, and I think I may have figured out a solution WITHOUT using querystrings.

I created a recursive function to solve the problem. The code is below:

private string GetNavigatedNodeIndex( TreeNodeCollection tnc ) 
{
	foreach ( TreeNode tn in tnc ) 
	{
		if ( tn.NavigateUrl.Length > 0 && (
			Request.Url.AbsolutePath.IndexOf( tn.NavigateUrl ) > -1 ||
			Request.Url.AbsoluteUri.IndexOf( tn.NavigateUrl ) > -1 ) )
		{
			return( tn.GetNodeIndex() );
		}

		string index = GetNavigatedNodeIndex( tn.Nodes );
		if ( index != null ) 
		{
			tn.Expanded = true;
			return( index );
		}
	}
	return( null );
}

Now, just handle the TreeView's PreRender event and call the function:

private void TreeView1_PreRender(object sender, System.EventArgs e)
{
	TreeView1.SelectedNodeIndex = GetNavigatedNodeIndex( TreeView1.Nodes );
}

Let me know if this solution works for you! Good luck!

 

[greggiepoo]

Sorry, just realized that in function GetNavigatedNodeIndex, you don't need to check Request.Url.AbsolutePath, since Request.Url.AbsoluteUri contains the path. So the correct code is:

private string GetNavigatedNodeIndex( TreeNodeCollection tnc ) {
...
        if ( tn.NavigateUrl.Length > 0 && 
            Request.Url.AbsoluteUri.IndexOf( tn.NavigateUrl ) > -1 )
...