Shell_NotifyIcon实现任意托盘图标的隐藏与再现

发TB_HIDEBUTTON消息来隐藏托盘图标并不完美，会留下一块空白

仔细看一下NOTIFYICONDATA结构，发现了dwState

如果dwStateMask为NIS_HIDDEN，则当dwState为NIS_HIDDEN时图标隐藏；当dwState为NIS_SHAREDICON时图标显示

代码参考：

#define _WIN32_IE 0x0500

#include 
#include 

struct TRAYDATA
{
  HWND hwnd;                
  UINT uID;                
  UINT uCallbackMessage;    
  DWORD Reserved[2];        
  HICON hIcon;                
};

void ShowTrayIcon(LPCWSTR lpwszIcon, BOOL bShow)
{
  HWND hWnd,hWndPaper;
  DWORD dwProcessId;
  int nButtonCount;
  HANDLE hProcess;
  LPVOID lpAddress;
  TBBUTTON tb;
  
  hWnd = FindWindow(TEXT("Shell_TrayWnd"), NULL);
  hWnd = FindWindowEx(hWnd, 0, TEXT("TrayNotifyWnd"), NULL);
  hWndPaper = FindWindowEx(hWnd, 0, TEXT("SysPager"), NULL);
  if(!hWndPaper)
    hWnd = FindWindowEx(hWnd, 0, TEXT("ToolbarWindow32"), NULL);
  else
    hWnd = FindWindowEx(hWndPaper, 0, TEXT("ToolbarWindow32"), NULL);

  GetWindowThreadProcessId(hWnd, &dwProcessId);
  hProcess = OpenProcess(PROCESS_ALL_ACCESS
    |PROCESS_VM_OPERATION
    |PROCESS_VM_READ
    |PROCESS_VM_WRITE,
    0,
    dwProcessId);
  lpAddress = VirtualAllocEx(hProcess,0, 0x4096, MEM_COMMIT, PAGE_READWRITE);
  nButtonCount = SendMessage(hWnd, TB_BUTTONCOUNT, 0, 0);
  
  for(int i = 0 ; i < nButtonCount - 1; i++)
  {
    SendMessage(hWnd, TB_GETBUTTON, i, (LPARAM)lpAddress);
    ReadProcessMemory(hProcess, lpAddress, &tb, sizeof(TBBUTTON), 0);

    if(tb.iString != -1)
    {
      TRAYDATA trayData;
      WCHAR wszBuff[MAX_PATH] = {0};
      WCHAR *pwsz = NULL;
      ReadProcessMemory(hProcess, (LPVOID)tb.iString, wszBuff, MAX_PATH, 0);
      ReadProcessMemory(hProcess, (LPVOID)tb.dwData, &trayData, sizeof(TRAYDATA), 0);
      pwsz = wcsstr(wszBuff, lpwszIcon);
      if (pwsz)
      {
        NOTIFYICONDATA nid;
        nid.cbSize = sizeof(NOTIFYICONDATA);
        nid.hWnd = trayData.hwnd;
        nid.uID = trayData.uID;
        nid.uFlags = NIF_STATE;
        nid.dwState = bShow?NIS_SHAREDICON:NIS_HIDDEN;
        nid.dwStateMask = NIS_HIDDEN;
        Shell_NotifyIcon(NIM_MODIFY, &nid);
      }
    }
  }
  VirtualFreeEx( hProcess, lpAddress, 0, MEM_RELEASE);
  CloseHandle(hProcess);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
  ShowTrayIcon(L"音量", FALSE);  //隐藏音量图标
  //ShowTrayIcon(L"音量", TRUE);  //显示音量图标
  return 0;
}

以上代码稍微解释一下吧：

任务栏的通知区域是个Toolbar，发TB_GETBUTTON消息可以获取Toolbar上某个按钮的信息

因为是要跨进程缓冲区的，所以需要用到ReadProcessMemory

获取到的TBBUTTON的dwData是个结构指针的，微软没有公开，但在网上可以找到：

struct TBBUTTONDATA 
{ 
    HWND hwnd; //the handle of the window on the taskbar 
    UINT uID; 
    UINT uCallbackMessage; 
    DWORD Reserved[2]; 
    HICON hIcon; 
};