Re: calling base-constructor - C# Discussion Boards

VC 6 code won't compile in .Net

5-Sep-02 12:17

Ouch. Well the control that I am removing is just a tab page in the tab control. I'll just switch focus to another tab page and then remove the one I want.

Sh*tty bug. Hope they will fix it soon.

Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n

Ryan Cromwell5-Sep-02 2:56

Ryan Cromwell

5-Sep-02 2:56

I have an Explorer extension that implements the IContextMenu interface. It all compiles fine in vc6 but if I open and hence convert it in vc7 (.net) it tells me that interface hasn't been defined. In my class file I can right click on the word IContextMenu and go to definition and life is good. all win32 defines are correct. Would there be a problem with the SDK if it was installed before .Net. Maybe I'll check the SDK update...

Re: VC 6 code won't compile in .Net

Stephane Rodriguez.5-Sep-02 3:08

Stephane Rodriguez.

5-Sep-02 3:08

From what I read, you are not using C# (C# forum).

-IContextMenu is defined in ShlObj.h which is not a default header automatically included by vc.

-IID_IContextMenu is defined in ShlGuid.h

-You must link with either uuid.lib or shell32.lib

And I swallow a small raisin.

calling base-constructor

Rüpel5-Sep-02 2:53

Rüpel

5-Sep-02 2:53

hi,

i'm designing an exception for my program and have the following problem. i want an additional constructor, which gets an int as paramter, builds a string out of it and calls the base-classes constructor with a string.

something like

class MyException : ApplicationExcpetion
{
  ...
  public MyException(int errorCode)
  {
    string message;
    switch(errorCode)
    {
      case // blabla, setting message here correctly
      default: message="unkown errorcode"; break;
    }
    base(message);
  }
}

but C# tells me: "Use of keyword base is not valid in this context" Frown | :(

i'm stuck. anyone any idea?

thx!

:wq

jparsons5-Sep-02 3:06

5-Sep-02 3:06

You can only call the base constructor like the following.

<br />
class MyException: ApplicationException<br />
{<br />
  pubilc MyException(int errorcode) : base ( MyException.GetErrorString(errorcode) ) {<br />
     // Constructor logic<br />
   }<br />
}<br />

The base constructor can only be called in that location.

Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n

Rüpel5-Sep-02 3:15

Rüpel

5-Sep-02 3:15

yeah, with GetErrorString being a static function is does work - thanks a lot!

sometimes it's like a blocking in your head, when you're coding all day long... Roll eyes | :rolleyes:

:wq

leppie5-Sep-02 3:41

5-Sep-02 3:41

I would also prefer to be able to delay the base construction. Look at my case.

class MyException: ApplicationException
{
int errorcode;
pubilc MyException() {
errorcode = GetErrorCode();
base ( MyException.GetErrorString(errorcode) );
}
}

Now I wouldnt have to call the GetErrorCode() function everytime when i need to throw it Smile | :)

Maybe there is a way to pre-initialise some variables... Confused | :confused:

MYrc : A .NET IRC client with C# Plugin Capabilities. See
http://sourceforge.net/projects/myrc for more info. Big Grin | :-D

jparsons5-Sep-02 12:19

Drag and Drop into a node of a treeview

5-Sep-02 12:19

leppie wrote:
Maybe there is a way to pre-initialise some variable

You could use a static constructor to preinitialize some variables.

Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n

Bill Dean4-Sep-02 11:36

Bill Dean

4-Sep-02 11:36

Hi all,

Does anyone know how to determine which node of a treeview control the mouse pointer is over when a drop occurs? Maybe I am asking the wrong question: I want to allow the user to drag something from a listbox control onto a particular node of a tree view so that the dragged object can be added as a child node.

Any thoughts?

Thanks,
Bill

Re: Drag and Drop into a node of a treeview

Ryan Cromwell5-Sep-02 2:49

Ryan Cromwell

5-Sep-02 2:49

//Gets the point relative to the treeview
Point dragPoint = tv.PointToClient( new Point(e.X, e.Y) );
//Gets the treenode
TreeNode target = tv.GetNodeAt( dragPoint.X, dragPoint.Y );

Re: Drag and Drop into a node of a treeview

Bill Dean5-Sep-02 4:19

Bill Dean

5-Sep-02 4:19

It's always so simple once you know what the answer is. Wink | ;)

Thanks.

Parameters question

leppie4-Sep-02 10:29

4-Sep-02 10:29

I have 3 functions. All 3 the functions are identical except for a type and a function.

Now i want to combined all three into one. I assume it would be,

void CombinedFunction(Type type, SomeHandler function);

No the problem i have is, is that not all of the functions share the same parameters. All 3 have common parameters, but one has 2 extra parameters.

Would i HAVE to overload that function to pass any of the functions as a parameter.

Hope that makes sense Smile | :)

Thanx

MYrc : A .NET IRC client with C# Plugin Capabilities. See
http://sourceforge.net/projects/myrc for more info. Big Grin | :-D

Re: Parameters question

jparsons5-Sep-02 2:59

5-Sep-02 2:59

I'm a little bit confused by what you are saying but I believe that you can solve your problem by uses a variable number of arguments.

void CombinedFunction(params object[] args)

Jared
jparsons@jparsons.org
www.prism.gatech.edu/~gte477n

Re: Parameters question

leppie5-Sep-02 3:13

Re: Replace with a C# Regex?

5-Sep-02 3:13

O ya I solved this, noted though far down the optional parameter thread Blush | :O

The easier, better way was just to overload the function as the 2 optional parameters had fixed values when used in that context. Smile | :)

And...the function works beautifully Roll eyes | :rolleyes:

MYrc : A .NET IRC client with C# Plugin Capabilities. See
http://sourceforge.net/projects/myrc for more info. Big Grin | :-D

Replace with a C# Regex?

Zombies with Coffee, LLC4-Sep-02 9:25

Zombies with Coffee, LLC

4-Sep-02 9:25

I am using regex (regular expressions) in my C# application. I am pulling out the first name like this...

Regex regName = new Regex( @"(?<Last>\S+), (?<First>\S+)" );
Match pMatch  = regName.Match( "Doe, John" );
Text strFirst = pMatch.Groups[ "First" ].Value;

Question: If the user changes the name to 'Jane', how can I use regular expressions to replace the first name?

If strFirst = "Jane", then I want a new string to be "Doe, Jane".

Thanks!!

Eric Gunnerson (msft)4-Sep-02 10:17

Eric Gunnerson (msft)

4-Sep-02 10:17

You'll want to use Regex.Replace, and then create a replacement string. Something like:

Regex regName = new Regex( @"(?<last>S+), (?<first>S+)");

regName.Replace (string, @"\k<last>, Jane");

The \k refers to whatever matched the "Last" capture.

If you're playing with regex, you might like this utility:

http://www.gotdotnet.com/userarea/keywordsrch.aspx?keyword=regular%20expression%20workbench

Clickety

David Stone4-Sep-02 12:20

David Stone

4-Sep-02 12:20

Eric, there's a link tool down at the bottom. Very handy. Just highlight and click link[^]

http://www.gotdotnet.com/userarea/keywordsrch.aspx?keyword=regular%20expression%20workbench [^]

David Stone

But Clinton wasn't a predictable, boring, aging, lying, eloquent, maintainer-of-the-status-quo. He was a predictable, boring-but-trying-to-look-hip, aging-and-fat-but-seemingly-oblivious-to-it, lying-but-in-sadly-blatant-ways, not-eloquent-but-trying-to-make-up-for-it-by-talking-even-more, bringer-in-of-scary-and-potentially-dangerous-new-policies. And there was also Al Gore. It just wasn't *right*.

Shog⁹

Unsafe Question

Nick Parker4-Sep-02 9:24

Nick Parker

4-Sep-02 9:24

Is it safe to assume that anytime you do some sort of COM Interop with a dll that wasn't written using the .NET Framework that the method call needs to be prefixed with the unsafe marker, or is this only needed when the method deals with pointers that are outside the bounds of .NET to handle directly?

[System.Runtime.InteropServices.DllImport("kernel32.dll")]
    unsafe int SomeFunction(....);

Nick Parker

Re: Unsafe Question

leppie4-Sep-02 9:39

4-Sep-02 9:39

U only have to specify unsafe if the compiler complains Laugh | :laugh:

No, but really unsafe only needs to be declared if you are using pointer notation in C# ( *, &, ->). It is recommneded though (as far as I am aware) to use the Marshalling class as far as possible, else they wouldnt have called it "unsafe". Smile | :)

Cheers

MYrc : A .NET IRC client with C# Plugin Capabilities. See
http://sourceforge.net/projects/myrc for more info. Big Grin | :-D

Re: Unsafe Question

Nick Parker4-Sep-02 9:43

Nick Parker

4-Sep-02 9:43

leppie wrote:
U only have to specify unsafe if the compiler complains

Somehow I believe more people than you think use this method. Smile | :)

Nick Parker

Optional parameters

Nnamdi Onyeyiri4-Sep-02 8:21

Nnamdi Onyeyiri

4-Sep-02 8:21

Is it possible to make a method to have options parameters, without defining the function for each valid configuration?

Suspicious | :suss: Email: theeclypse@hotmail.com URL: http://www.onyeyiri.co.uk
"All programmers are playwrights and all computers are lousy actors."

Re: Optional parameters

Nick Parker4-Sep-02 8:56

Nick Parker

4-Sep-02 8:56

Not sure, however you could always overload the function. Smile | :)

Nick Parker

Re: Optional parameters

leppie4-Sep-02 9:33