Re: Converting a pointer to a C# type - C# Discussion Boards

4-Jun-03 4:14

I'm messing around with VS Add-ins and the debugger and I have this VC7 app I'm debugging. To make a long story short, I'm trying to find the value of an Expression in the debugger. The variable is a char* and the Expression value is the pointer value of that char* converted to a string (ex. "0x#####").

So how can I take that Expression value ("0xWhatever"), convert it to an Int32 and then actually get the string value out of it and copy it to a C# string?

static unsafe string GetStringExpressionValue(Expression expr)
{
	string strValue = "";

	if (expr.IsValidValue)
	{
		if (expr.Type == "char *")
		{
			char * chrPtr = (char *)(Convert.ToInt32(expr.Value));
			// WHAT NOW???  Or am I on the wrong track?
			MessageBox.Show(expr.Name + " = " + expr.Value);
		}
		else
			MessageBox.Show(expr.Name + " is not a string variable.");
	}
	else
		MessageBox.Show("Expression was not valid");

	return strValue;
}

Jason Henderson

My articles

"The best argument against democracy is a five-minute conversation with the average voter." - Winston Churchill

Ranjan Banerji4-Jun-03 6:39

Ranjan Banerji

4-Jun-03 6:39

Shouldnt u be able to say strVal = chrPtr or strVal = new string( chrPtr )? I have not tried it but it seems to make sense.

Jason Henderson4-Jun-03 9:30

4-Jun-03 9:30

My conversion to an int32 was not working.

Would you happen to know how to get the process address in C#?
I have a char* address and when I convert it to a string it shows someting totally different than the actual string. I'm sure its because the address needs to be added to the debugged app's base address.

Jason Henderson

My articles

"The best argument against democracy is a five-minute conversation with the average voter." - Winston Churchill

Ranjan Banerji4-Jun-03 9:37

Ranjan Banerji

4-Jun-03 9:37

Oh! ok , now I get your problem. And of course I don't have an answer to your question. Once I get home I may fool around with it and see what I can get. Sorry. Hopefully by then you would have found the solution.

leppie4-Jun-03 16:48

leppie

4-Jun-03 16:48

string chrPtr = Marshal.PtrToStringAnsi( new IntPtr(expr.Value) ));

<a TITLE="See my user info" href=http://www.codeproject.com/script/profile/whos_who.asp?id=38829>leppie<a>::<a TITLE="Go to all articles  written by me" href=http://www.codeproject.com/script/articles/list_articles.asp?userid=38829>AllocCPArticle</a>(<a TITLE="Go to my latest, greatest article!" href=http://www.codeproject.com/useritems/dfamachine.asp >Generic DFA State Machine for .NET</a>);

Jason Henderson4-Jun-03 17:08

4-Jun-03 17:08

Will this give me the string stored in the pointer if the pointer is from another app (namely one I'm debugging and extending the debugger with an add-in)?

Jason Henderson

My articles

"The best argument against democracy is a five-minute conversation with the average voter." - Winston Churchill

leppie4-Jun-03 17:32

leppie

4-Jun-03 17:32

It should...

<a TITLE="See my user info" href=http://www.codeproject.com/script/profile/whos_who.asp?id=38829>leppie<a>::<a TITLE="Go to all articles  written by me" href=http://www.codeproject.com/script/articles/list_articles.asp?userid=38829>AllocCPArticle</a>(<a TITLE="Go to my latest, greatest article!" href=http://www.codeproject.com/useritems/dfamachine.asp >Generic DFA State Machine for .NET</a>);

Jason Henderson5-Jun-03 5:17

5-Jun-03 5:17

That didn't work.

The expression's value is a mem address like 0xfffff.. as a string so perhaps my stringhextoint conversion funtion is not working right.

Jason Henderson

My articles

"The best argument against democracy is a five-minute conversation with the average voter." - Winston Churchill

Jim Stewart5-Jun-03 4:01

Jim Stewart

5-Jun-03 4:01

This article[^] might help.

α.γεεκ

Fortune passes everywhere.
Duke Leto Atreides

Switch

Andy H4-Jun-03 2:43

Andy H

4-Jun-03 2:43

I cannot seem to find the answer to this simple question:

In VB I can write:

Select Case n<br />
   <br />
   Case 1, 2, 3:<br />
 <br />
   Case 4, 5:<br />
<br />
End Select

How can I do this with Switch{} in C#?

Re: Switch

Philip Fitzsimons4-Jun-03 2:51

Philip Fitzsimons

4-Jun-03 2:51

<code>switch (n)
{
   case 1: case 2: case 3:
   {
      // stuff
      break;
   }
   case 4: case 5:
   {
      // stuff
      break;
   }
}</code>

<h6 align="right">
<hr width="29%"/>
"<i><font size="2">When the only tool you have is a hammer, a sore thumb you will have.</font></i>"
</h6>

Re: Switch

Bernhard Brieger4-Jun-03 2:56

Bernhard Brieger

4-Jun-03 2:56

switch(i)
{
case 1:
case 2:
case 3:
...
break;
case 4:
case 5:
...
break;
}

Hope it helps

Bernhard

Creating an image mask?

FruitBatInShades4-Jun-03 2:10

FruitBatInShades

4-Jun-03 2:10

Does anybody know how to create an image mask using gdi+ I want all transparent pixels to remain transparent but all other colors to become black.

I been playing with color matrix but can't figuire out how to do it Cry | :((

Any Ideas?

4-Jun-03 3:04

private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
Image myImage = Image.FromFile("BigIcon_001-1.ico");
e.Graphics.DrawImage(myImage, 20, 20);

ColorMatrix myColorMatrix = new ColorMatrix();

myColorMatrix.Matrix00 = 0.0f;
myColorMatrix.Matrix11 = 0.0f;
myColorMatrix.Matrix22 = 0.0f;
myColorMatrix.Matrix33 = 1.0f;
myColorMatrix.Matrix44 = 1.0f;

ImageAttributes imageAttr = new ImageAttributes();
imageAttr.SetColorMatrix(myColorMatrix);

Rectangle rect = new Rectangle(60, 20, myImage.Width, myImage.Height);
e.Graphics.DrawImage(myImage, rect, 0, 0, myImage.Width, myImage.Height, GraphicsUnit.Pixel, imageAttr);
}

Enjoy ;o)

FruitBatInShades4-Jun-03 11:30

FruitBatInShades

4-Jun-03 11:30

Thanks valeria Big Grin | :-D

FruitBatInShades5-Jun-03 0:42

FruitBatInShades

5-Jun-03 0:42

Sorry to bug you valeria but do you know of any tutorials that explain how the colourMatrix works? Big Grin | :-D