Help on Windows API please??

[MAtkins]

Hi:

I'm trying to find someone who knows the Windows API, especially as used in C# .NET.

Specifically, I'm trying to use:
GetMenuItemInfo(hMenu, MenuItemID, false, ref mif);

I need to specify also that I'm trying to control one application from within another one. The platform is Windows 2000 Pro.

I have the MenuID in hMenu, checked by IsMenu and the MenuItemID is also a valid ID (I also tried this using the position with the 3rd param set to true).
The param mif is a structure (see below).

I even used AttachThreadInput(nhWndThreadID, nThisThreadID, 1);
This returns 1, indicating success.

No matter what I do, GetMenuItemInfo returns 0 and does not produce any information on any given menu item.

[StructLayout(LayoutKind.Sequential)]
public struct MENUITEMINFO
{
public uint cbSize;
public uint fMask;
public uint fType;
public uint fState;
public int wID;
public int hSubMenu;
public int hbmpChecked;
public int hbmpUnchecked;
public int dwItemData;
public string dwTypeData;
public uint cch;
public int hbmpItem;
}

[Banfa]

When calling functions like this you need to set the size parameter in the structure first before the call so that the API can identify what version of the strcuture you have passed it.

In c this would be done by

   mif.cbSize = sizeof(mif);
 

beforecalling GetMenuItemInfo

[MAtkins]

Thanks for the reply.
I am filling the cbSize variable with the size of mif as you suggested.
Any other ideas?

Here is the whole proc:

private void setMenuCommand(int hWnd, int hMenu, uint nPos, int MenuItemID)
{
string sLabel = "";
StringBuilder sBuffer = new StringBuilder(nBuffLen);
WinAPI.MENUITEMINFO mif = new WinAPI.MENUITEMINFO();

mif.dwTypeData = null;// sBuffer.ToString();
try
{
int a = WinAPI.GetMenuItemInfo(hMenu, MenuItemID, false, ref mif);
if(a == 0)
{
//throw new Win32Exception(Marshal.GetLastWin32Error());
return;
}
sBuffer = new StringBuilder((int)(mif.cch + 1));
mif.cbSize = (uint)Marshal.SizeOf(typeof(WinAPI.MENUITEMINFO));
mif.fMask = 0x10;
mif.dwTypeData = sBuffer.ToString();
a = WinAPI.GetMenuItemInfo(hMenu, MenuItemID, false, ref mif);
if(a != 0)
{
mif.dwTypeData = new String('\0', (int)(mif.cch + 1));
sLabel = mif.dwTypeData.Trim();
if(sLabel != "" && sLabel != "-")
{
MenuCommand oMnuCmd = new MenuCommand();
oMnuCmd.sLabel = sLabel;
oMnuCmd.hMenu = hMenu;
oMnuCmd.nPos = nPos;
oMnuCmd.hMenuItemID = MenuItemID;
oMnuCmd.hWin = hWnd;
clMenuCommands.Add(sLabel, oMnuCmd);
}
}
}
catch(Exception exp)
{
throw new Exception("Error setting menu command: " + exp.Message);
}
}

[Banfa]

See embedded comments in the code in itallic bold

private void setMenuCommand(int hWnd, int hMenu, uint nPos, int MenuItemID)
{
    string sLabel = "";
    StringBuilder sBuffer = new StringBuilder(nBuffLen);
    WinAPI.MENUITEMINFO mif = new WinAPI.MENUITEMINFO();
 
    mif.dwTypeData = null;// sBuffer.ToString();
    try
    {
         // 1. You call GetMenuItemInfo here
        int a = WinAPI.GetMenuItemInfo(hMenu, MenuItemID, false, ref mif);
        if(a == 0)
        {
            //throw new Win32Exception(Marshal.GetLastWin32Error());
             // 3. so the function returns here
            return;
        }
        sBuffer = new StringBuilder((int)(mif.cch + 1));
         // 2. Before you set the cbSize parameter here
        mif.cbSize = (uint)Marshal.SizeOf(typeof(WinAPI.MENUITEMINFO));
        mif.fMask = 0x10;
        mif.dwTypeData = sBuffer.ToString();
        a = WinAPI.GetMenuItemInfo(hMenu, MenuItemID, false, ref mif);
        if(a != 0)
        {
            mif.dwTypeData = new String('\0', (int)(mif.cch + 1));
            sLabel = mif.dwTypeData.Trim();
            if(sLabel != "" && sLabel != "-")
            {
                MenuCommand oMnuCmd = new MenuCommand();
                oMnuCmd.sLabel = sLabel;
                oMnuCmd.hMenu = hMenu;
                oMnuCmd.nPos = nPos;
                oMnuCmd.hMenuItemID = MenuItemID;
                oMnuCmd.hWin = hWnd;
                clMenuCommands.Add(sLabel, oMnuCmd);
            }
        }
    }
    catch(Exception exp)
    {
        throw new Exception("Error setting menu command: " + exp.Message);
    }
}
 

[MAtkins]

DUMB!! Sheesh, I can't believe I didn't see that.
THANKS!!

It returns a 1 now and is apparantly getting the information.
When I look at dwDataType I'm getting "\0\0\0\0\0\0\0\0\".

How do I get the label on the meni item?

[MAtkins]

I've made a couple changes hoping to get some information from the label:
mif.fMask = 0x10;
mif.dwTypeData = new String('\0', (int)(mif.cch + 1));
a = WinAPI.GetMenuItemInfo(hMenu, MenuItemID, false, ref mif);

It's returning a null now.
I've read Microsoft's docs and some other stuff but frankly, I'm pretty confused as to how I'm to get the menu item's text.
Can you help?

Oh, and how did you encase the code above so it looks like code?

[Banfa]

I did this (again in C rather than C#), note I accessed the menu by position rather than by command but that shouldn't make any difference. This worked so I guess it's just a matter of setting the MENUITEMINFO structure correctly before calling the function.

    MENUITEMINFO mif;
    char name[50];
 
    mif.cbSize = sizeof(mif);
    mif.fMask = MIIM_TYPE;
    mif.fType = MFT_STRING;
    mif.dwTypeData = name;
    mif.cch = sizeof(name);
 
    if ( GetMenuItemInfo(GetMenu(hwnd), 0, TRUE, &mif ) )
    {
        // Here we have the menu item text in name
    }
 

Format you code by putting it between [code] and [/code] when you post it.

[MAtkins]

Hmm, I sure appreciate your help.
It's still not working for me.

dwDataType always returns null.
Also, I noticed that even though I set dwDataType = sLabel when the function returns it does not change sLabel. As you can see, mif is sent as a reference.

string sLabel = new String('\0', 265);
            WinAPI.MENUITEMINFO mif = new WinAPI.MENUITEMINFO();
 
            mif.cbSize = (uint)Marshal.SizeOf(typeof(WinAPI.MENUITEMINFO));
            mif.fMask = WinAPI.MIIM_TYPE;
            mif.fType = WinAPI.MFT_STRING;            
            mif.dwTypeData = sLabel;
 
            try
            {
                int a = WinAPI.GetMenuItemInfo(hMenu, nPos, true, ref mif);
                if(a != 0)
                {                    
                    //mif.dwTypeData = new String('\0', (int)(mif.cch + 1));
                    sLabel = mif.dwTypeData;
                    if(sLabel != "" && sLabel != "-")
                    {
                        MenuCommand oMnuCmd = new MenuCommand();
                        oMnuCmd.sLabel = sLabel;
                        oMnuCmd.hMenu = hMenu;
                        oMnuCmd.nPos = nPos;
                        oMnuCmd.hMenuItemID = MenuItemID;
                        oMnuCmd.hWin = hWnd;
 
                        //clMenuCommands.Add(sLabel, oMnuCmd);
                    }
                }
            }
 

Is MIIM_TYPE = 16 and MFT_STRING = 0??
Does cbSize end up equaling 45?
Also, is it possible that I'm having trouble because the menu is in an app other than mine?

[MAtkins]

I did one more thing and it looks like I've finally got it.
I called the proc twice (which is what MS says to do).
The first time to get the size of dwDataType and the second time to fill it.

Thanks very much for your help.