MBR IT/.NET 247 : Problem with Shell interop on microsoft.public.dotnet.framework.interop

Problem with Shell interop

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This message was discovered on microsoft.public.dotnet.framework.interop.

FramMla

Thanks if you can bring me some answer elements or a link to an answer

I searched the web for 48h without result.

Those remarks are directly based on the example given with the VS (2003)
that you can find localy at:
C:\Program Files\Microsoft Visual Studio .NET
2003\SDK\v1.1\Samples\Technologies\Interop\Applications\ShellCmd

1-Interactions with the keyboard accelerator Windows+E
-----------------------------------------------------------------
When the menu is loaded, the keyboard accelerator Windows+E, that run
Explorer, doesn't work.
But, the probleme get worst if you add some code: interaction with Windows+E
can acts on your menu, showing your winforms or making explorer using lot
and lot of memory.
Question: how to trap the keyboard accelerator Windows+E to make it work
correctly or inactivate it instead of making your application bug ?

2-How to bug the example
------------------------------
Just change the IContextMenu interface implementation (ShellExtLib.cs, at
the end):
replace:
[PreserveSig()]
int QueryContextMenu(uint hmenu, uint iMenu, int idCmdFirst, int
idCmdLast, uint uFlags);
[PreserveSig()]
void InvokeCommand (IntPtr pici);
[PreserveSig()]
void GetCommandString(int idcmd, uint uflags, int reserved,
StringBuilder commandstring, int cch);

by:
[PreserveSig()]
void GetCommandString(int idcmd, uint uflags, int reserved,
StringBuilder commandstring, int cch);
[PreserveSig()]
void InvokeCommand (IntPtr pici);
[PreserveSig()]
int QueryContextMenu(uint hmenu, uint iMenu, int idCmdFirst, int
idCmdLast, uint uFlags);

By this way, the menu will never appear.
Question: the order of the functions (interface signature) is it so
important ?

3-Go farther
--------------
How implement the interfaces IContextMenu2 and IContextMenu3 without bugging
explorer ?
In my case, i iterate the IContextMenu implementation by a:
[ComImport(),
InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
GuidAttribute("000214f4-0000-0000-c000-000000000046")]
public interface IContextMenu2
{
// IContextMenu2 method
[PreserveSig()]
int HandleMenuMsg(
uint uMsg, //UINT
IntPtr wParam, //WPARAM
IntPtr lParam //LPARAM
);
}
[ComImport(),
InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
GuidAttribute("bcfce0a0-ec17-11d0-8d10-00a0c90f2719")]
public interface IContextMenu3
{
// IContextMenu3 method
[PreserveSig()]
int HandleMenuMsg2(
uint uMsg, //UINT
IntPtr wParam, //WPARAM
IntPtr lParam, //LPARAM
IntPtr plResult //LRESULT *
);
}
I get the GUIDS on a example. But, the IContextMenu3 GUID let me perplex...
Who knows exactly the ShellGUIDS ?

4-Bonus
----------
To show the descriptive message in the status bar, wich is invoked by the
IContextMenu.GetCommandString, the StringBuilder DOES NOT WORK (i tried
longly)
So i used two functions (one for ASCII, the other for UNICODE):
private void pokeAnsiString(IntPtr memPtr, string theString, int sizeMax)
{
int i;

for(i=0; i<theString.Length; i++)
{
if(i==sizeMax-1)
break;
Marshal.WriteByte(memPtr, i, (byte)theString[i]);
}
Marshal.WriteByte(memPtr, i, 0); //terminal 0
}
private void pokeUnicodeString(IntPtr memPtr, string theString, int sizeMax)
{
byte[] bytes;
int i;

bytes=System.Text.Encoding.Unicode.GetBytes(theString);
for(i=0; i<bytes.Length; i++)
{
if(i==sizeMax-2)
break;
Marshal.WriteByte(memPtr, i, bytes[i]);
}
Marshal.WriteByte(memPtr, i, 0); //terminal 0 (unicode)
Marshal.WriteByte(memPtr, i+1, 0); //terminal 0(unicode)
}
that give the waited results.

Thanks for answers.

Sincerely
Francis MOREL.

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Reply to this message...

Mattias Sjögren

[Original message clipped]

Yes, it's essential.

[Original message clipped]

They must redeclare all methods in their base interfaces. So you have
to copy all methods from IContextMenu to IContextMenu2 and so on.

[Original message clipped]

Not sure what you're asking here. Your IContextMenu3 IID is correct.

[Original message clipped]

This code is very inefficient. You can write all characters in one
call with Marshal.Copy().

Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

Reply to this message...

	System.IntPtr
	System.Runtime.InteropServices.ComInterfaceType
	System.Runtime.InteropServices.GuidAttribute
	System.Runtime.InteropServices.Marshal
	System.Text.Encoding
	System.Text.StringBuilder

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