Having a problem with ImGui_ImplWin32_WndProcHandler

[ch1ppadev]

The error:
Severity Code Description Project File Line Suppression State Details
Error C3861 'ImGui_ImplWin32_WndProcHandler': identifier not found imguikey C:\Users\workspace\Documents\Visual Studio 2022\Projects\imguikey\main.cpp 97

so when I try to build it, im having that error i've been trying to fix it for the past 4 days and still have no luck. Can someone please help me fix it? this might be a dumb request but please bear with me as i'm trying to learn. the part that is having the error is this

LRESULT CALLBACK WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam) {
if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
return true;

ImGuiIO& io = ImGui::GetIO();

switch (msg) {
case WM_SIZE:
    if (wParam != SIZE_MINIMIZED) {
        d3dpp.BackBufferWidth = LOWORD(lParam);
        d3dpp.BackBufferHeight = HIWORD(lParam);
        d3dDevice->Reset(&d3dpp);
    }
    return 0;
case WM_SYSCOMMAND:
    if ((wParam & 0xfff0) == SC_KEYMENU)
        return 0;
    break;
case WM_DESTROY:
    PostQuitMessage(0);
    return 0;
case WM_CLOSE:
    PostQuitMessage(0);
    return 0;
case WM_KEYDOWN:
    if (wParam == VK_ESCAPE)
        PostQuitMessage(0);
    return 0;
}

return DefWindowProc(hWnd, msg, wParam, lParam);

}

[ocornut]

The ImGui_ImplWin32_WndProcHandler function needs to be forward declared in your code.
We don't declare it in imgui_impl_win32.h for subtle technical reasons.

See imgui_impl_win32.h:

// Win32 message handler your application need to call.
// - Intentionally commented out in a '#if 0' block to avoid dragging dependencies on <windows.h> from this helper.
// - You should COPY the line below into your .cpp code to forward declare the function and then you can call it.
// - Call from your application's message handler. Keep calling your message handler unless this function returns TRUE.

#if 0
extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
#endif

If you search for ImGui_ImplWin32_WndProcHandler in our repo, you will find 5 places where it is used, and in all 5 places the function is forward declared:

// Forward declare message handler from imgui_impl_win32.cpp
extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);

LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
        return true;
....

[ch1ppadev]

thanks alot man