问题描述
我正在尝试在虚幻引擎 4 中创建 Systemtray 图标。 我不是 C++ 专家。到目前为止，这是我从互联网上剥取的代码
#define NOTIFICATION_TRAY_ICON_MSG (WM_USER + 0x100)
AddTrayIcon(hwnd,1,NOTIFICATION_TRAY_ICON_MSG,0);
void AddTrayIcon(HWND hWnd,UINT uID,UINT uCallbackMsg,UINT uIcon) {
//CREATE SYSTEN TRAY ICON.---------------------------------------------------------------------
NOTIFYICONDATA nid;
nid.hWnd = hWnd;
nid.uID = uID;
nid.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
nid.uCallbackMessage = uCallbackMsg;
FString ThePath = FPaths::ConvertRelativePathToFull(FPaths::RootDir()) ;
FString GameName = FApp::GetName();
ThePath.Append(GameName);
ThePath.Append(".exe");
GEngine->AddOnScreenDebugMessage(-1,12.f,FColor::White,ThePath);
WORD id = 0;
nid.hIcon = ExtractAssociatedIcon(nullptr,ThePath.GetChararray().GetData(),&id);
//LPCWSTR iconfile = "C:/Temp/icon.ico";
//ExtractIconEx(iconfile,NULL,&(nid.hIcon),1);
//strcpy(nid.szTip,"Tool Tip");
//SEND MESSAGE TO SYstem TRAY TO ADD ICON.--------------------------------------------
Shell_NotifyIcon(NIM_ADD,&nid);
}
LRESULT CALLBACK WndProc(HWND hWnd,UINT message,WParaM wParam,LParaM lParam)
{
switch (message)
{
case NOTIFICATION_TRAY_ICON_MSG:
{
// This is a message that originated with the
// Notification Tray Icon. The lParam tells use exactly which event
// it is.
switch (lParam)
{
case WM_LBUTTONDBLCLK:
{
const int IDM_EXIT = 100;
POINT pt;
GetCursorPos(&pt);
HMENU hmenu = CreatePopupMenu();
InsertMenu(hmenu,MF_BYPOSITION | MF_STRING,IDM_EXIT,L"Exit");
TrackPopupMenu(hmenu,TPM_LEFTALIGN | TPM_LEFTBUTTON | TPM_BottOMALIGN,pt.x,pt.y,GetActiveWindow(),NULL);
break;
}
}
}
}
return 0;
}
图标已创建，但我无法右键单击并从中获取弹出菜单 我也无法弄清楚 LRESULT CALLBACK WndProc() 函数是如何被触发的。
谁能帮忙谢谢
解决方法
您没有正确初始化 NOTIFYICONDATA。具体而言，您没有设置其 cbSize 或 uVersion 成员，这会直接影响 Shell_NotifyIcon() 通过您分配给 uCallbackMessage 成员的消息与您的应用程序交互的方式。以下 MSDN 文档对此进行了详细讨论：
Notifications and the Notification Area: Define the NOTIFYICONDATA Version
此外，您说要在右键单击时显示弹出菜单，但您的 WndProc() 正在寻找左键双击 .
但更重要的是，您需要将您的 WndProc() 与您提供给 HWND 的 Shell_NotifyIcon() 相关联，这样您才能真正接收到您的 NOTIFICATION_TRAY_ICON_MSG 消息。由于您尝试使用的 HWND 不是您的创建者，UE4 是创建者，因此您必须subclass the window，例如：
#define NOTIFICATION_TRAY_ICON_MSG (WM_USER + 0x100)
void AddTrayIcon(HWND hWnd,UINT uID,UINT uCallbackMsg,UINT uIcon);
void RemoveTrayIcon(HWND hWnd,UINT uID);
LRESULT CALLBACK SubclassProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam,UINT_PTR uIdSubclass,DWORD_PTR dwRefData);
...
HWND hwnd = ...; // GetActiveWindow(),etc
if (SetWindowSubclass(hwnd,&SubclassProc,1,0))
AddTrayIcon(hwnd,NOTIFICATION_TRAY_ICON_MSG,0);
...
void AddTrayIcon(HWND hWnd,UINT uIcon) {
//CREATE SYSTEM TRAY ICON.---------------------------------------------------------------------
NOTIFYICONDATA nid = {};
nid.cbSize = sizeof(nid);
nid.hWnd = hWnd;
nid.uID = uID;
nid.uFlags = NIF_ICON | NIF_MESSAGE | NIF_TIP;
nid.uCallbackMessage = uCallbackMsg;
nid.uVersion = NOTIFYICON_VERSION_4;
FString ThePath = FPaths::ConvertRelativePathToFull(FPaths::RootDir()) ;
FString GameName = FApp::GetName();
ThePath.Append(GameName);
ThePath.Append(".exe");
GEngine->AddOnScreenDebugMessage(-1,12.f,FColor::White,ThePath);
WORD id = 0;
nid.hIcon = ExtractAssociatedIcon(nullptr,ThePath.GetCharArray().GetData(),&id);
//LPCWSTR iconfile = L"C:/Temp/icon.ico";
//ExtractIconEx(iconfile,NULL,&(nid.hIcon),1);
//strcpy(nid.szTip,"Tool Tip");
//SEND MESSAGE TO SYSTEM TRAY TO ADD ICON.--------------------------------------------
if (Shell_NotifyIcon(NIM_ADD,&nid))
Shell_NotifyIcon(NIM_SETVERSION,&nid);
}
void RemoveTrayIcon(HWND hWnd,UINT uID) {
//REMOVE SYSTEM TRAY ICON.---------------------------------------------------------------------
NOTIFYICONDATA nid = {};
nid.cbSize = sizeof(nid);
nid.hWnd = hWnd;
nid.uID = uID;
//SEND MESSAGE TO SYSTEM TRAY TO REMOVE ICON.--------------------------------------------
Shell_NotifyIcon(NIM_DELETE,&nid);
}
LRESULT CALLBACK SubclassProc(HWND hWnd,DWORD_PTR dwRefData)
{
switch (uMsg)
{
case WM_NCDESTROY:
RemoveTrayIcon(hWnd,1);
RemoveWindowSubclass(hWnd,uIdSubclass);
break;
case NOTIFICATION_TRAY_ICON_MSG:
{
// This is a message that originated with the
// Notification Tray Icon. The lParam tells use exactly which event
// it is.
switch (LOWORD(lParam))
{
case NIN_SELECT:
case NIN_KEYSELECT:
case WM_CONTEXTMENU:
{
const int IDM_EXIT = 100;
POINT pt;
GetCursorPos(&pt);
HMENU hmenu = CreatePopupMenu();
InsertMenu(hmenu,MF_BYPOSITION | MF_STRING,IDM_EXIT,L"Exit");
SetForegroundWindow(hWnd);
int cmd = TrackPopupMenu(hmenu,TPM_LEFTALIGN | TPM_LEFTBUTTON | TPM_BOTTOMALIGN | TPM_NONOTIFY | TPM_RETURNCMD,pt.x,pt.y,hWnd,NULL);
PostMessage(hWnd,WM_NULL,0);
if (cmd == IDM_EXIT)
{
...
}
break;
}
}
return 0;
}
}
return DefSubclassProc(hWnd,uMsg,wParam,lParam);
}
话虽如此，您确实应该创建自己的窗口来处理与系统托盘的交互。您可以直接调用 CreateWindowEx() 来创建一个隐藏的 message-only window，然后将您图标的 WndProc() 与该窗口相关联。您不需要使用 UE4 窗口：
LRESULT CALLBACK SysTrayWndProc(HWND hWnd,LPARAM lParam);
...
LPCTSTR SysTrayWndClass = TEXT("MySysTrayWnd");
HINSTANCE hInst = ...; // GetModuleHandle(NULL),etc
WNDCLASS wc = {};
wc.lpfnWndProc = &SysTrayWndProc;
wc.hInstance = hInst;
wc.lpszClassName = SysTrayWndClass;
RegisterClass(&wc);
HWND hSysTrayIconWnd = CreateWindowEx(0,SysTrayWndClass,HWND_MESSAGE,hInst,NULL);
if (hSysTrayIconWnd) {
AddTrayIcon(hSysTrayIconWnd,0);
}
...
if (hSysTrayIconWnd) {
RemoveTrayIcon(hSysTrayIconWnd,1);
DestroyWindow(hSysTrayIconWnd);
}
...
LRESULT CALLBACK SysTrayWndProc(HWND hWnd,LPARAM lParam)
{
switch (uMsg)
{
case NOTIFICATION_TRAY_ICON_MSG:
{
// This is a message that originated with the
// Notification Tray Icon. The lParam tells use exactly which event
// it is.
switch (LOWORD(lParam))
{
case NIN_SELECT:
case NIN_KEYSELECT:
case WM_CONTEXTMENU:
{
const int IDM_EXIT = 100;
POINT pt;
GetCursorPos(&pt);
HMENU hmenu = CreatePopupMenu();
InsertMenu(hmenu,TPM_LEFTALIGN | TPM_LEFTBUTTON | TPM_BOTTOMALIGN,0);
break;
}
}
return 0;
}
case WM_COMMAND:
if (lParam == 0 && LOWORD(wParam) == IDM_EXIT)
{
...
}
break;
}
return DefWindowProc(hWnd,lParam);
}