Error Message - C# Discussion Boards

Re: Displaying + (Plus) sign to node without adding child node

3-Jan-07 0:50

Your trick is somewhat user unfriendly. One of our chaps would call it "user hostile" Smile | :)

. Users are familiar with that small plus sign as an indication of the existence of more child nodes under this current node. They click on it to expand the node, not to add other nodes.

You should put the adding functionality in another button/ToolStripButton/ToolStripMenuButton/etc... somewhere near the TreeView or even in the TreeView's context menu. Yet if you insist on doing your trick, for sure it's doable in C#. You can Add you fake node by code

MyTreeView.Nodes["MyNodeName"].Nodes.Add("Fake Node");
MyTreeView.Nodes["MyNodeName"].Collapse()

Then in the TreeView itself handle the event TreeView.BeforeExpand. Check for the expanding node. If it's the one you want remove the fake node and add whatever you like.

-- modified at 6:55 Wednesday 3rd January, 2007

Of course you can put your plus sign in an image, put that image in an ImageList, and associate it with the TreeView. This is another way of displaying the plus sign, but I'm not sure if the user clicked on the image -not the node itself- what event would fire. You can check it out easily , can't you?

Regards

s v joshi3-Jan-07 1:41

s v joshi

3-Jan-07 1:41

hi
This will display one child node names "fake node" , so after expanding it first i have to remove that first fake node it and then fill the actual child nodes. i am trying how to remove that node first but so far not able to do so.

In my application there are thousands of child nodes that i received from another machine. i do not want to store that data in memory so i will fetch that data only if user asks for it by expanding the node.

Re: Displaying + (Plus) sign to node without adding child node

Nader Elshehabi3-Jan-07 2:01

Re: Displaying + (Plus) sign to node without adding child node

3-Jan-07 2:01

sandeepvilasjoshi wrote:
so after expanding it first i have to remove that first fake node

Not so. The BeforeExpand event happens before the parent node is expanded at all. So in the handler you remove your fake node bfore the parent node would ever expand. Thus no user will ever see your fake node. Removing it would be easy by one line in the handler.

e.Node.Nodes[0].Remove();

Also I made two more suggestions in my previous post that would give an alternate way of doing it.

sandeepvilasjoshi wrote:
i do not want to store that data in memory

Each tree node won't take more than few bytes long in memory. Most modern computers got memory of 256Mb or more. So if you want to go through all these trouble just to save 200-300 Kbs of memory -which is very trivial- you are absolutely wrong. The above method will make a major performance hit in your program -try it-. Unless you got a million or more nodes I wouldn't recommend your idea. After all it's still your choice. Try this, and that and profile -some sort of speed test- your application, then decide where to go.

Regards

PIEBALDconsult3-Jan-07 3:42

PIEBALDconsult

3-Jan-07 3:42

Nader Elshehabi wrote:
"user hostile"

I agree, in fact if you need to allow the user to add items the TreeView may not be the control to use. If you insist, then I suggest a context menu, with Add, Remove, Edit, etc.

Some times the envelope pushes back.

How to make a chart in C#

phantanagu3-Jan-07 0:26

phantanagu

3-Jan-07 0:26

Could somebody give me a sample code of chart control?

Re: How to make a chart in C#

User 66583-Jan-07 0:29

User 6658

3-Jan-07 0:29

Lots of charts are here:

http://www.codeproject.com/cs/miscctrl/#Miscellaneous+Controls

regards

modified 12-Sep-18 21:01pm.

Re: How to make a chart in C#

Luc Pattyn3-Jan-07 5:03

Luc Pattyn

3-Jan-07 5:03

Over 40 people already published one on CodeProject

Smile | :)

Luc Pattyn

Error Message

morteza573-Jan-07 0:03

morteza57

3-Jan-07 0:03

hi, i have a windows application. in load event of my form i retrieve data from " Microsoft Access" database.
when i build or run form,i see several Error MessageBox with this content : "object reference not set to an instance of an object ".
after that i submit these , Program Runs Successfully!!
what is my problem?
thanks

Re: Error Message

User 66583-Jan-07 0:16

User 6658

3-Jan-07 0:16

You somewhere access a variable that is set to null.
The debugger will show you which variable this is, just run the Debug build.

regards

modified 12-Sep-18 21:01pm.

Re: Error Message

morteza573-Jan-07 1:21

morteza57

3-Jan-07 1:21

Thanks

getting File path??

Venkatesh.P2-Jan-07 22:28

Venkatesh.P

2-Jan-07 22:28

How to get the file path on mouse right click in c#?

Thanks & Regards,
Venkat

Re: getting File path?? [modified]

Bhupi Bhai2-Jan-07 22:39

Bhupi Bhai

2-Jan-07 22:39

Please search on msdn first .....
then search on google .....
followed by looking in the previous posts ......
If you still do not get answers, post a message here ...

Regards,
Bhupi Bhai.

Venkatesh.P2-Jan-07 23:06

Venkatesh.P

2-Jan-07 23:06

I had posted this message only after searching in google and msdn..

I have a windows based application in c#. On Windows explorer context menu i added one context menu item named "MyContext" . when the user right clicks on a file or folder, i have "MyContext" menu(This is the context menu item that i have added to the windows explorer context menu). When i click "MyContext" menu, i have to execute one application. In that application page load, i want to get the file or folder path that the user right clicked.

How to get that file path?? Please help

-- modified at 5:19 Wednesday 3rd January, 2007

Thanks & Regards,
Venkat

Nader Elshehabi3-Jan-07 1:13

3-Jan-07 1:13

What you are talking about is called Windows Shell programming -not context menu Smile | :)

-. In CodeProject there is a very good section about Shell programming. i think you can find the anwer there. Click here[^].

Regards

Venkatesh.P3-Jan-07 21:50

Venkatesh.P

3-Jan-07 21:50

I agree that this is windows shell programming. In that path is generated by args[0]. I have an application, which contains a tab control. inside the tabcontrol i am having a textbox. I am getting the string args[0] value from the program.cs file. I want to assign the string args[0] value to the textbox. How to assign that value to the textbox?
This is the program.cs file

static class Program
{
public static string pathkey;

public static string path
{
get
{
return pathkey;
}
set
{
pathkey = value;
}
}
[STAThread]
static void Main(string[] args)
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
Form1 objform = new Form1();
try
{
Program.pathkey= args[0].ToString ();

}
catch (Exception ex)
{
}

Form1.cs
*********
In my form1 load, i am assigning the value to the textbox

txtLocation.Text = Program.pathkey.ToString();

But i am not able to get the value?

In registry i have the entry as C:\Documents and Settings\venkadeshp\My Documents\Visual Studio 2005\Projects\HCI_DMS ConsoleApplication\bin\Debug\HCI_DMS ConsoleApplication.exe %1 . But i couldnt find the file path in the string args[0] in the program.cs main function?

Thanks & Regards,
Venkat

Nader Elshehabi3-Jan-07 22:35

Problem with reading INI Files, and a listview question.

3-Jan-07 22:35

Venkatesh.P wrote:
How to assign that value to the textbox?

Simple. In your Main method

 [STAThread]
static void Main(string[] args)
{
    Application.EnableVisualStyles();
    Application.SetCompatibleTextRenderingDefault(false);
    Application.Run(new Form1(args[0]));
}

and in Modify your form constructor to this

Form1(string thePath)
{
    MyFileName = thePath;
    //more code
}

PS.
The first argument would be the path to your exe file BTW, and the second argument is the "%1" command which is used to instruct the program to open the file -not print it for example-. The Thrid argument -i.e. args[2]- I bilieve is what you are looking for. Try to show them one by one in MessageBoxs ro see the value of each before deciding which to pass to the Form's constructor.

Regards

HydroIT2-Jan-07 22:14

Re: Problem with reading INI Files, and a listview question.

2-Jan-07 22:14

Well, I've found several INI Readers here, which helped, but they didn't solve my real problem.
My INI file I have (which I cannot change, I only read from it), has stuff like this:

[Section]<br />
Key=Value<br />
Key=Value2<br />
Key=Value3<br />
Key=Value4<br />
Key=Value5

etc... Same key, but 5 different values. Every INI Reader I've seen so far, will only read the first one.
Does anyone have any solution?

Secondly, In my dialog I have this listview, which I want to fill from a self-made method. The listview is simply called "listView1", but whenever I try to use that name in my method (i.e. listView1.Items.Add("Test");) I get this error:
An object reference is required for the nonstatic field, method, or property 'WindowsApplication1.Form1.listView1'
What do I need to do to make it work :p

CPallini2-Jan-07 23:13

CPallini

2-Jan-07 23:13

(1) You have done you own version of INI file, so you have to make a reader for that...

(2) I don't know (maybe posting the code will help).

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Problem with reading INI Files, and a listview question.

HydroIT3-Jan-07 0:20

Re: Problem with reading INI Files, and a listview question.

3-Jan-07 0:20

(1) No, I haven't. As I specific earlier, the INI file is made by an external program (a game, to be specific).

(2) What code? the INI Reader I found?

CPallini3-Jan-07 0:38

CPallini

3-Jan-07 0:38

(1) OK, my hypothesys was wrong, you didn't write that. Anyway, IMHO, you have to write a reader for such non-compliant INI file.

(2) That was referring to the listview trouble you experienced.

Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Problem with reading INI Files, and a listview question.

HydroIT3-Jan-07 0:41

Re: Problem with reading INI Files, and a listview question.

3-Jan-07 0:41

(1) Well, any tips? :p

(2) errr.. I deleted it because I couldn't get it, but I used something like this (well it had more, but this suffices to prodouce the same error):

public static void LoadFavorites()<br />
{<br />
  listView1.Add.Items("test");<br />
}

Stefan Troschuetz3-Jan-07 2:16

Stefan Troschuetz

3-Jan-07 2:16

2) In case the method is static you cannot access instance variables.

"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning." - Rick Cook

www.troschuetz.de

Re: Problem with reading INI Files, and a listview question.

CPallini3-Jan-07 2:38

CPallini

3-Jan-07 2:38

(1) The Windows API GetPrivateProfileSection loads a buffer will all section content (keys are NULL separated). I don't know if it will be of any help to you.
(2) Ok, let's forget about it...
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

Re: Problem with reading INI Files, and a listview question.

PIEBALDconsult3-Jan-07 3:53

PIEBALDconsult

3-Jan-07 3:53

A) The only built-in way I know of to read an INI file is with the Windows API and P/Invoke:

        <br />
[System.Runtime.InteropServices.DllImport ( "kernel32" , SetLastError=true , EntryPoint="GetPrivateProfileString" )]<br />
        private unsafe static extern uint<br />
        API_GetPrivateProfileString<br />
        (<br />
            string lpAppName        <br />
        ,<br />
            string lpKeyName        <br />
        ,<br />
            string lpDefault        <br />
        ,<br />
            byte*  lpReturnedString <br />
        ,<br />
            int    nSize            <br />
        ,<br />
            string lpFileName<br />
        ) ;<br />
<br />
        public unsafe static int<br />
        GetPrivateProfileString<br />
        (<br />
            string     lpAppName        <br />
        ,<br />
            string     lpKeyName        <br />
        ,<br />
            string     lpDefault        <br />
        ,<br />
            out string lpReturnedString <br />
        ,<br />
            int        nSize            <br />
        ,<br />
            string     lpFileName<br />
        )<br />
        {<br />
            int    result ;<br />
            byte[] temp   = new byte [ nSize ] ;<br />
<br />
            fixed ( byte* ptemp = temp )<br />
            {<br />
                result = (int) API_GetPrivateProfileString<br />
                (<br />
                    lpAppName        <br />
                ,<br />
                    lpKeyName        <br />
                ,<br />
                    lpDefault        <br />
                ,<br />
                    ptemp            <br />
                ,<br />
                    nSize            <br />
                ,<br />
                    lpFileName<br />
                ) ;<br />
            }<br />
<br />
            lpReturnedString = PIEBALD.Lib.LibStr.FromByteArray ( temp , true ).Substring ( 0 , result ) ;<br />
<br />
            return ( result ) ;<br />
        }<br />

B) You need to provide a reference to an instance to listView1.Items.Add(), the literal "Test" won't work.

Re: Problem with reading INI Files, and a listview question.

HydroIT3-Jan-07 7:16