Desktop Functions:

   Smart Device Functions:

Show Recent Changes
Subscribe (RSS)
Misc. Pages
Helpful Tools
Suggested Reading
Website TODO List
Support Forum
Download Visual Studio Add-In

Terms of Use
Privacy Policy
TCITEM (user32)
Specifies or receives the attributes of a tab item.

C# Signature:

    struct TCITEM
        public uint mask;
        public int state;
        public int statemask;
        public IntPtr text;
        public int size;
        public int image;
        public int param;

VB Signature:

Declare Function TCITEM Lib "user32.dll" (TODO) As TODO

User-Defined Types:


Alternative Managed API:

Do you know one? Please contribute it!



Tips & Tricks:

Please add some!

Sample Code:

I slightly edited some things, so maybe it doesn't work out of the box, should be 99% fine though.


    #region code
    TCITEM tcitem = new TCITEM();
    tcitem.size = 200;
    uint ProcessID;
    GetWindowThreadProcessId((IntPtr)handle, out ProcessID);
    IntPtr process = OpenProcess(ProcessAccessFlags.VMOperation | ProcessAccessFlags.VMRead |
    ProcessAccessFlags.VMWrite | ProcessAccessFlags.QueryInformation, false, ProcessID);

    IntPtr pszTextPtr = VirtualAllocEx(process, IntPtr.Zero, 512, AllocationType.Commit, MemoryProtection.ReadWrite);
    IntPtr tcitemPtr = VirtualAllocEx(process, IntPtr.Zero, (uint)Marshal.SizeOf(typeof(TCITEM)), AllocationType.Commit, MemoryProtection.ReadWrite);

    const int TCIF_STATE = 0x10;
    const int TCIF_TEXT = 0x1;
    tcitem.mask = TCIF_STATE | TCIF_TEXT;

    tcitem.text = pszTextPtr;
    string L_buf = "nasenmann ";
    IntPtr TextPtr = Marshal.StringToHGlobalAnsi(L_buf);
    L_buf = "├╝berschrieben";
    int bytesReaded;
    WriteProcessMemory(process, pszTextPtr, TextPtr, 512, IntPtr.Zero);
    IntPtr ptr = Marshal.AllocHGlobal(Marshal.SizeOf(tcitem));
    Marshal.StructureToPtr(tcitem, ptr, true);
    tcitem.size = 1; // ├╝berschrieben
    WriteProcessMemory(process, tcitemPtr, ptr, Marshal.SizeOf(tcitem), IntPtr.Zero);
    int res = SendMessage(handle, TCM_GETITEMA, index, tcitemPtr);
    ptr = Marshal.AllocHGlobal(512);
    ReadProcessMemory(process, pszTextPtr, ptr, 512, out bytesReaded);
    L_buf = Marshal.PtrToStringAnsi(ptr);
    ptr = Marshal.AllocHGlobal(Marshal.SizeOf(tcitem));
    ReadProcessMemory(process, tcitemPtr, ptr, (int)Marshal.SizeOf(tcitem), out bytesReaded);
    tcitem = (TCITEM)Marshal.PtrToStructure(ptr, tcitem.GetType());
    VirtualFreeEx(process, tcitemPtr, 0, FreeType.Release);
    VirtualFreeEx(process, pszTextPtr, 0, FreeType.Release);


    #region defines
    public enum FreeType
    Decommit = 0x4000,
    Release = 0x8000,

    enum ProcessAccessFlags : uint
    All = 0x001F0FFF,
    Terminate = 0x00000001,
    CreateThread = 0x00000002,
    VMOperation = 0x00000008,
    VMRead = 0x00000010,
    VMWrite = 0x00000020,
    DupHandle = 0x00000040,
    SetInformation = 0x00000200,
    QueryInformation = 0x00000400,
    Synchronize = 0x00100000

    public enum AllocationType
    Commit = 0x1000,
    Reserve = 0x2000,
    Decommit = 0x4000,
    Release = 0x8000,
    Reset = 0x80000,
    Physical = 0x400000,
    TopDown = 0x100000,
    WriteWatch = 0x200000,
    LargePages = 0x20000000

    public enum MemoryProtection
    Execute = 0x10,
    ExecuteRead = 0x20,
    ExecuteReadWrite = 0x40,
    ExecuteWriteCopy = 0x80,
    NoAccess = 0x01,
    ReadOnly = 0x02,
    ReadWrite = 0x04,
    WriteCopy = 0x08,
    GuardModifierflag = 0x100,
    NoCacheModifierflag = 0x200,
    WriteCombineModifierflag = 0x400

    [DllImport("user32.dll", SetLastError = true)]
    static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);
    [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
    static extern IntPtr VirtualAllocEx(IntPtr hProcess, IntPtr lpAddress,
       uint dwSize, AllocationType flAllocationType, MemoryProtection flProtect);
    static extern IntPtr OpenProcess(ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwProcessId);
    [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
    static extern bool VirtualFreeEx(IntPtr hProcess, IntPtr lpAddress,
       int dwSize, FreeType dwFreeType);
    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool ReadProcessMemory(
     IntPtr hProcess,
     IntPtr lpBaseAddress,
    IntPtr lpBuffer,
     int dwSize,
     out int lpNumberOfBytesRead
    [DllImport("kernel32.dll", SetLastError = true)]
    static extern bool WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, IntPtr lpBuffer, int nSize, IntPtr lpNumberOfBytesWritten);


You can find some more ideas here: (though it is in German)

I am also working on a generic method to pass structs. It is working for an arbitrary number of strings contained in the struct and is very user friendly. Once it is finished I will post it somewhere on the net as well.

Also, you can use the code here for any situation where you have a struct that contains a pointer to some other structure that you then again need to fill (and read).


Please edit this page!

Do you have...

  • helpful tips or sample code to share for using this API in managed code?
  • corrections to the existing content?
  • variations of the signature you want to share?
  • additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

Access directly from VS:
Terms of Use
Edit This Page
Find References
Show Printable Version