Re: Winforms.TreeView node limit - C# Discussion Boards

11-Jul-10 10:27

I am using VS2005 (C#) and I gather the tree view has a limit of 64K nodes per level.
Is there a later version where the limit is higher?
I am working on an application which could have a very large nummer of root nodes and I would like to avoid embarassment at the wrong moment.
BTW, it is populated on demand, i.e. as a node is epxanded.
Thanks.

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OriginalGriff11-Jul-10 10:46

OriginalGriff

11-Jul-10 10:46

Isn't that rather a lot? How long is your user going to spend paging through that lot, looking for the node they want? Surely there must be a better way... Big Grin | :-D

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That by counting the rings on a tree trunk, you can tell how many other trees it has slept with.

Trollslayer11-Jul-10 11:11

11-Jul-10 11:11

It's for analysing DVB (broadcast video) files, possibly 10GB so I was just checking on an easy way of bulletproofing. Video is the main part of it but I'm being careful.
Yes, occasionally we have to look for a certain sequence but we don't always know what it is until we find it. D'Oh! | :doh:

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Mycroft Holmes11-Jul-10 12:29

Mycroft Holmes

11-Jul-10 12:29

I have found the performance of the treeview is terrible when trying to load large data sets. As in minutes to populate the TV. I was not aware of the 64k limit as I don't think that volume is viable.

Never underestimate the power of human stupidity
RAH

Trollslayer11-Jul-10 12:48

11-Jul-10 12:48

This why I will be loading on demand, i.e. only loading the children when an individual node is epxanded.
I will also be looking at other views but a tree view offers a lot of advantages in this case.

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Mycroft Holmes11-Jul-10 14:18

Mycroft Holmes

11-Jul-10 14:18

I got the impression there were a lot of root nodes. You would have to load on demand if some of your root nodes have 64k nodes.

Can you page the nodes by some grouping so the root node would have a group level then a sub node collection. I think this is going to come down to data mangement.

Some of the 3rd party tools mat not have the 64k limitations?

Never underestimate the power of human stupidity
RAH

Trollslayer11-Jul-10 21:43

11-Jul-10 21:43

Yes, that is the approach I mentioned above, only populating the sub nodes when a node is expanded.
I doubt there would be more than 64K nodes per root but there could potentially be up to a million nodes in total.
Because of this there will be an inital decoding phase where an internal XMLDocument will be created with the usual progress bar to keep the user happy but I want to keep the treeview response as snappy as I can and it's not that difficult to do.
You know what users are like!

BTW, typical structure with DVB is:
Table
Sections (subtable)
Elements/descriptors
Descriptor lists
Descriptor structures

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How to Inherit C++/CLI Interface in C#?

Mycroft Holmes11-Jul-10 23:09

Mycroft Holmes

11-Jul-10 23:09

Trollslayer wrote:
there could potentially be up to a million nodes in total

I don't even want to think about shoving that sort of volume into a TV.

I wonder if you can add nodes by block, insert 1000, release the UI and insert another 1000. Or can you prepare the tree sub nodes in memory and drop in the lot in 1 hit.

Trollslayer wrote:
You know what users are like!

I made the mistake of putting a long fetch into another thread and not disabling the button. Then I had to sit there and watch my BA hammer away at the button all the while complaining that nothing had happened. She had spawned 20 or so threads in about 2 seconds.

Never underestimate the power of human stupidity
RAH

glitteringsound11-Jul-10 2:24

glitteringsound

11-Jul-10 2:24

Hello,

I have declared an interface in C++/CLI and made it assembly(DLL). Now I want that interface to be implement by C# app. I have added the reference but still my C# assembly does not detecting my C++/CLI interface and says "Could not found: Are you missing some assembly refernce......"

How to solve this issue?

Regards Usman

Re: How to Inherit C++/CLI Interface in C#?

Luc Pattyn11-Jul-10 6:00

Luc Pattyn

11-Jul-10 6:00

assuming you have declared a public interface in some namespace and built it into a DLL, you need to add a reference to that DLL and include a using statement for the namespace (or use fully qualified types).

Smile | :)

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Please use <PRE> tags for code snippets, they preserve indentation, and improve readability.

Sharing strings between unmanaged and managed code

Keith Vitali10-Jul-10 11:39

Keith Vitali

10-Jul-10 11:39

Hello,

I have some native C++ code that interacts with my managed C# app through delegates and function pointers. Normally, I have the following setup for basic types in my native C++ DLL.

So, for example this function set interacts with the managed code and updates a variable of type short.

typedef int (__stdcall* GET_SHORT)(short &value, int ID);
// function pointer to hold delegate.
GET_SHORT getAttShort = NULL; 

//! Store a delegate for future use. This will be called by the C# app.
extern "C" __declspec(dllexport) void SetShortHandler(GET_SHORT handler) 
{
    getDicomAttShort = handler;
}

//! This method calls the method in C#
int GetAttribute(short &value, int ID)
{
    // value gets updated by managed app.
    if (getDicomAttShort) return getAttShort(value, ID);
    return -1; // no handler set
}

Here, the managed app sets the delegate by calling SetShortHandler which sets the function pointer and then the method is called through GetAttribute()..

No, this works great for types like short, int, double, long... However, I am at a loss as to how I can get it to work with strings. I like to use STL strings and I want to do something similar as the code above but with strings instead of basic types.

Any ideas? Would appreciate any help.

Keith

Re: Sharing strings between unmanaged and managed code

Keith Vitali11-Jul-10 6:20

Keith Vitali

11-Jul-10 6:20

Never mind. Figured it out.

/K

Set Exit code in win mobile C#

alto10-Jul-10 10:37

alto

10-Jul-10 10:37

I have a simple application that need to return value on exit to the his caller process.
the calling process use Process p = Process.Start(startInfo); to call the second one.
In regular .Net I can us the System.Environment.ExitCode to do it, but in the compact framework its doesn't supported.

Re: Set Exit code in win mobile C#

DaveyM6910-Jul-10 23:04

DaveyM69

10-Jul-10 23:04

Have you tried changing the Main method to return an int?

Dave

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Showing Main Form Quickly?

ali_zdn10-Jul-10 9:29

ali_zdn

10-Jul-10 9:29

i have a windows form application, and i want that when i execute the program, program must show me the main form quickly, but my program firstly do some operations (connecting to sql, filling the combobox etc. )
because in form_load function i call a function to fill the combo with sql database's datas.
But user does not want to wait, user wants to see the form very quickly.
In other words, user wants my program to connect sql and to fill the combo AFTER form has been shown to the user.

Bigdeak10-Jul-10 10:12

Bigdeak

10-Jul-10 10:12

The easiest way to make this possible is to put this operations in the Shown Event of the showing form.

public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();

            this.Shown += new System.EventHandler(this.Form1_Shown);
        }

        private void Form1_Shown(object sender, EventArgs e) {
            MessageBox.Show("Hello world after showing the Form");

            // Here you SQL Connection etc.
        }
    }

Hope it could help you...

ali_zdn10-Jul-10 10:36

ali_zdn

10-Jul-10 10:36

it does not work

is there anyone having idea_?

Richard Blythe10-Jul-10 11:34

Richard Blythe

10-Jul-10 11:34

This is a textbook example where you need multi-threading.

http://msdn.microsoft.com/en-us/library/cc221403(VS.95).aspx[^]

The mind is like a parachute. It doesn’t work unless it’s open.

Ravi Bhavnani10-Jul-10 13:43

Ravi Bhavnani

10-Jul-10 13:43

FTFY: http://msdn.microsoft.com/en-us/library/4852et58.aspx[^]

(The OP's probably using WinForms, not Silverlight.)

/ravi

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PIEBALDconsult10-Jul-10 15:06

PIEBALDconsult

10-Jul-10 15:06

Why show the user the form if it's not ready to use?

OriginalGriff10-Jul-10 20:30

OriginalGriff

10-Jul-10 20:30

So he doesn't double click it again, and again, and again... My wife does that - if whatever she runs doesn't show up pretty much immediately, she just clicks and clicks until something happens. Or she gets angry and breaks the keyboard. WTF | :WTF:

Did you know:
That by counting the rings on a tree trunk, you can tell how many other trees it has slept with.

PIEBALDconsult11-Jul-10 3:15

PIEBALDconsult

11-Jul-10 3:15

So she'll keep clicking on the ListBox or whatever until it loads instead?

OriginalGriff11-Jul-10 3:46

OriginalGriff

11-Jul-10 3:46

She wouldn't recognise a listbox if it got up and bit her on the arse.

She works on the principle that "it works with telephones, so it should work here".

Did you know:
That by counting the rings on a tree trunk, you can tell how many other trees it has slept with.