Re: How To Move An Item In A Hierarchy - C# Discussion Boards

Your objects seems akin to Controls on a WinForm, so why not use their model? Each Control has a ControlCollection holding its children, and a Parent property pointing to its parent (null for any topmost Control).

When in doubt, look for similar situations and reuse existing concepts.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Message Removed

Yes, I'm using WPF and ObservableCollections. The question then is, in a hierchical collection, how do you know a node's index position? Seems like I'll need to recurse.

If it's not broken, fix it until it is

See my comments a couple of threads down. You need to be crystal clear about what your hierarchy (and the internal relationships - parent/child/sibling/etc) represent, so you can clearly define your add/delete/move/whatever operations.
Yes, given that a hierarchical structure is involved, you will be up for recursion (or possibly an equivalent iteration). For a many-children "tree", search the big G or Wikip for "trie". That might just hand it to you on a platter.

Cheers,
Peter

Software rusts. Simon Stephenson, ca 1994.

Give a node a reference to its parent? That's what I've done in every tree-like data structure I've ever built.

Sounds like a good idea. Do you worry at all about dangling references?

If it's not broken, fix it until it is

No. .Net's garbage collector will clean up for me. If I remove a child, the fact that it still references its parent is irrelevant, as the child will be collected, and then it's no longer sitting on a reference.

Kevin Marois wrote:
I need to provide Move Up and Move Down functions.

I think Bob Janova's suggestion that you include in your Node-whatever base class a 'Parent field is the correct solution, and it will have so much additional functionality, in the long run, it's the "only" solution.

What you leave unspecified in your question are the interesting cases such as:

You wish to move up a child Node of a Parent Node:

a. assuming the Parent Node has other siblings prior to the the Node to be "promoted:" the "promoted node" then remains a sibling of the Parent node, but now precedes the prior sibling in the collection ?

b. assuming the node to be "promoted" is the first child of its Parent Node: the "promoted node" then becomes a sibling of its former Parent node, preceding its former Parent node in the collection ?

I think you can also easily see that you will need to think through other "edge cases" involving moving a Node "down" in the collection/tree.

Also consider that some tree data structures (in computer science algorithmic theory) are based on having a single root node from which all other Nodes descend, and other trees, as you see in the typical TreeView Control in .NET, are based on having an arbitrary collection in which any number of Nodes can be root-level.

Since you use the word "collection" here, I would assume you are allowing multiple root-nodes. In that case the top root-node cannot be moved up, and the last root-node cannot be moved down.

imho it's a useful convention to make the design choice that if the 'Parent field of a Node, in a collection-based tree, contains 'null, then the given Node is a "root-level" node.

Now if you are constructing your own "hierarchic visual display" of this collection/tree structure ... not using some existing TreeView control ... then ... welcome to recursion.

best, Bill

"Humans are amphibians ... half spirit and half animal ... as spirits they belong to the eternal world, but as animals they inhabit time. This means that while their spirit can be directed to an eternal object, their bodies, passions, and imaginations are in continual change, for to be in time, means to change. Their nearest approach to constancy, therefore, is undulation: the repeated return to a level from which they repeatedly fall back, a series of troughs and peaks.” C.S. Lewis

Hi All,

What it is i would like to do is add a new item into an existing sharepoint list. The fields in this item will be filled out using variables existing in my program.

I've had a look around the internet and its not making much sense so i was hoping one of you guys could shed some light on me?

Many thanks in advance! Smile | :)

This really should have been posted in the SharePoint forum. But since the damage is already done...

First, what version of SharePoint, WSS 3, MOSS 2007, 2010 Foundation?
Second, how are you accessing SharePoint? WebServices, server application, service, Client Object Model?

If you give more details about what you are doing you will get a better answer.

Failure is not an option; it's the default selection.

Hello,

I have one web based application using vb.net codebehing. Now i have to convert this into C#.net. Can anyone help me how to convert whole vb.net web application into C#.net web application. My application has 110 pages so its not possible to convert one by one page. Is it possible to convert whole application ?

Thanks & Regards

Do hard work, you will get your result sure !

You can use one of the conversion tools[^] to get the code converted, followed by a few sessions of build and test.

Binding 100,000 items to a list box can be just silly regardless of what pattern you are following. Jeremy Likness

Have a look at these tools:
Code Translation for .NET (C#<->VB.NET)[^]
Developer Fusion Convert C# to VB.NET [^]

There are more on the web. But they would not convert 100% successfully. These would help you to get a base to start with. Manual is the final and best way.

Sandeep Mewara
[My last tip/trick]: Browser back button issue after logout

I have a collection of NodeObject classes in a hierarchical list. The list can be any number of levels deep.

public class NodeModel : ViewModelBase
{
    public Guid Id { get; set; }
    public string Caption { get; set; }
    public string Description { get; set; }
    public NodeType Type { get; set; }
    public List<NodeModel> Children { get; set; }
}

How can I remove an item from the list using its Guid Id regardless of where it is in the list?

If it's not broken, fix it until it is

Just write a recursive delete method.

something like (psuedo code):

public bool DeleteNode(Guid id)
{
return DeleteNode(id, this);
}

private bool DeleteNode(Guid id, NodeModel model)
{
if (id == model.Id) delete model object here; return true;

foreach (NodeModel in Children)
{
if (DeleteNode(id, model))
return true;
}

return false;
}

If you delete an internal node, what do you do with its children? Your code would leave them orphaned...
Depending on what the original structure is meant to represent, it need rebuilding in some way after a deletion (or maybe deletion should be disallowed for some nodes...)
We need more information from the OP to define then solve his problem.

Cheers,
Peter

Software rusts. Simon Stephenson, ca 1994.

Message Removed

I was thinking more in terms of structures like B-trees (used in database indexing, etc), where deleting a node involves reconnecting any fragments (and in the case of a B-tree) possibly rebalancing the tree.
The point remains that we need to understand the semantics of the structure in order to know what a delete should do.

Cheers,
Peter

Software rusts. Simon Stephenson, ca 1994.

Any source code out there already for a GE Versimax E05 PLc so that I can exchange data using C#? Already looked at the drivers created already but little pricey for me.

For something so specific and vertical?? Probably not.

Google is your friend. I'd start with "Versimax E05 PLC C#" and start hunting.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Hi
This is Chandra and Good evening. My query is, i have one web page. In that web page i have GridView Control. At presnt i can able to export the data to Excel from Gridview control.I have also Charts control in the same Web Page which is displying sales information.

Here My Question is.. Is it possible to export the Chart control as well as Gridview data to Excel format.

Thanks
Chandrakanth

Chandrakanth

ChandrakanthGaddam wrote:
Is it possible to export the Chart control

Yes.

Look here: ASP.Net Chart Control-Exporting Chart to Excel FINALLY![^]

BTW, there is ASP.NET section[^] too. This section generally is for C#-Winforms queries.

Sandeep Mewara
[My last tip/trick]: Browser back button issue after logout

Hi Sandeep,
Thanks for your information. Meanwhile in my case i can not hard code the chat names because i have different types of grids like CategoryInfo,SubcategoryInfo Info,ProductInfo, SalesInfo etc. These are all grids contains lot of records and Each Grid has 3 types of charts. In this case how can i approach.

Thanks
Chandrakanth.

I provided a direction to start. I have not done it myself or played with it. You have to look around for tweaks you want. Try out, it might not be as hard as you think.

Sandeep Mewara
[My last tip/trick]: Browser back button issue after logout

I am doing a university website for my third year project using asp.net the website is only for university staff and registed students so when logging in password and user name need to be validated using the schools active directry this is my 1st website and i dont have any idea of active directry Cry | :((

plz help