Re: highspeed c#? - C# Discussion Boards

1-Jan-03 10:20

Does anyone know how to get the icon from a specified executable path? I know there is an Icon class and the Graphics class has a DrawIcon function, however I am not sure how they work together. Note that the icons will be coming from other applications, not necessarily from another C# application.

Nick Parker

You see the Standards change. - Fellow co-worker

Stephane Rodriguez.1-Jan-03 10:31

1-Jan-03 10:31

Nick Parker wrote:
Does anyone know how to get the icon from a specified executable path?

// System.Drawing.Icon constructor
public System.Drawing.Icon(
Type type,
string resource
);

(that's the equivalent of WIN32's LoadLibrary(path) + LoadResource(iconid))

doc here[^].

Nick Parker1-Jan-03 10:43

1-Jan-03 10:43

S.Rod, thanks, I had actually looked at this a few of the other 6 different constructors for the Icon class, however I wasn't/and am still not sure for exampple with your suggestion what to use as the Type and resource, where do they come from?

This below can't be right...

Icon i = new Icon(typeof(".exe"), ?);

Icon i = new Icon(Type.GetType(@"C:\Windows\System32\notepad.exe"),?);

I think I am shooting blanks here, thank you.

Nick Parker

You see the Standards change. - Fellow co-worker

Stephane Rodriguez.1-Jan-03 19:05

1-Jan-03 19:05

The type is internally passed to that documented method : type.Module.Assembly.GetManifestResourceStream(type, resource);

After checking out that call, I have seen it's currently not implemented in .NET 1.0. It always throws an exception.
If someone has .NET Everett installed, may be he can shed us a light on whether it's now implemented.
Otherwise, I am afraid you'll have to rely on P/Invoke : LoadLibrary() + LoadImage().

Once you have your icon handle, you just need to pass it to the System.Drawing.Icon(IntPtr handle) constructor.

In addition

Nick Parker2-Jan-03 5:51

2-Jan-03 5:51

.S.Rod. wrote:
Otherwise, I am afraid you'll have to rely on P/Invoke : LoadLibrary() + LoadImage().

Ok, I feel like the smoke is starting to clear now, thank you. After looking up a few of the functions on MSDN I came up with the following:

[DllImport("kernel32.dll",CharSet=CharSet.Auto)]
static public extern IntPtr LoadLibrary(string lpFileName);

[DllImport("user32.dll",CharSet=CharSet.Auto)]
static public extern IntPtr LoadImage(IntPtr hinst,
                  string lpszName,
                  uint uType,
                  int cxDesired,
                  int cyDesired,
                  uint fuLoad);

And then I implement it like this:

Graphics grfx = Graphics.FromHwnd(this.Handle);
Rectangle rect = new Rectangle();
rect.X = 0;
rect.Y = 0;
rect.Width = 16;
rect.Height = 16;
     IntPtr i  = API.API.LoadLibrary(app1);
IntPtr i2 = API.API.LoadImage(i, app1, 1, 0, 0, 0x0010);
Icon ico = System.Drawing.Icon.FromHandle(i2);
grfx.DrawIcon(ico, rect);

I have noticed when I step through it that LoadImage returns 0 for i2 and then when I try to create the ico Icon it throws a System.ArgumentException saying the Win32 handle I passed to Icon is invalid or the wrong type. Any ideas?

Nick Parker

You see the Standards change. - Fellow co-worker

Stephane Rodriguez.2-Jan-03 10:05

2-Jan-03 10:05

A few points :
- If LoadImage returns 0, that's because it has failed. There is no point in passing 0 as a handle in the FromHandle() method.
- To know more about the error, you can use the GetLastError() WIN32 function.
- LoadImage can be used in either of the following ways. Trouble is you are using a mix of it! Namely,
-- If LR_LOADFROMFILE is provided as last parameter value (0x0010), like you do, then the second parameter is the actual filename of the image. Doing so, you are directly loading a .bmp, .ico, .cur file. But, from what you told me first you wanted to do, you should not use LR_LOADFROMFILE.
-- If LR_LOADFROMFILE is not provided, then the first paramter is the module instance of the .dll or .exe, allright, and then the second parameter is the resource name. You must pass the resource name : that is either the translated resource ID (use a resource editor) obtained with MAKEINTRESOURCE, or the direct resource name as a string.

MAKEINTRESOURCE is an int --> LPSTR macro defined as is :
#define MAKEINTRESOURCE(i) (LPSTR)((DWORD)((WORD)(i)))

Nick Parker2-Jan-03 11:43

2-Jan-03 11:43

.S.Rod. wrote:
MAKEINTRESOURCE is an int --> LPSTR macro defined as is :
#define MAKEINTRESOURCE(i) (LPSTR)((DWORD)((WORD)(i)))

Unsure | :~

I have no idea how to convert that to a C# statement (I think I am lost again):

int MAKEINTRESOURCE(i)
{
return Convert.ToString(Convert.ToDouble(i)));
}

.S.Rod. wrote:
If LR_LOADFROMFILE is not provided, then the first paramter is the module instance of the .dll or .exe

That is what I am doing, correct?

.S.Rod. wrote:
You must pass the resource name : that is either the translated resource ID (use a resource editor) obtained with MAKEINTRESOURCE, or the direct resource name as a string.

I see, I think, so I need to switch the 2nd param to a resource ID huh? I will check into that. Tell me something, am I making something simple, hard? I know a little about Win32, I just havn't worked with it a lot, VB shop at work. Eek! | :eek:

Thanks S.Rod. I appreciate it.

Nick Parker

You see the Standards change. - Fellow co-worker

Stephane Rodriguez.2-Jan-03 18:58