c++ - Error LNK2019 unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)

Question

Error:

Severity Code Description Project File Line Error LNK2019 unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ) 
Severity    Code    Description Project File    Line
Error   LNK1120 1 unresolved externals  

Code:

#include "windows.h"
#include "tchar.h"
#include "d3d9.h"
#pragma comment(lib, "d3d9.lib")

LPDIRECT3D9 pDirect3D=NULL; 
LPDIRECT3DDEVICE9 pDirect3DDevice=NULL; 
const int segment = 50;
const int NV = segment*13;
struct CUSTOMVERTEX
{
   float x, y, z, rhv;
   
   DWORD color;
};
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZRHW|D3DFVF_DIFFUSE)

LPDIRECT3DVERTEXBUFFER9 pVertexBuffer=NULL; 

HRESULT InitialDirect3D(HWND hvnd)
{
   if((pDirect3D=Direct3DCreate9(D3D_SDK_VERSION))==NULL)
      return E_FAIL;
   D3DDISPLAYMODE Display;

   if(FAILED(pDirect3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &Display)))
      return E_FAIL;

   D3DPRESENT_PARAMETERS Direct3DParameter;
   ZeroMemory(&Direct3DParameter, sizeof Direct3DParameter);
 
   Direct3DParameter.Windowed=TRUE;
   Direct3DParameter.SwapEffect=D3DSWAPEFFECT_DISCARD;
   Direct3DParameter.BackBufferFormat=Display.Format;

   if(FAILED(pDirect3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hvnd,
                                     D3DCREATE_HARDWARE_VERTEXPROCESSING,
                                     &Direct3DParameter, &pDirect3DDevice)))
      return E_FAIL;
   return S_OK;
}
HRESULT RenderingDirect3D()
{
   if(pDirect3DDevice==NULL)
      return E_FAIL;
   pDirect3DDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(90, 150, 100), 1.f, 0);
   
   pDirect3DDevice->BeginScene();

   pDirect3DDevice->SetStreamSource(0, pVertexBuffer, 0, sizeof(CUSTOMVERTEX));
  
   pDirect3DDevice->SetFVF(D3DFVF_CUSTOMVERTEX);   

    pDirect3DDevice->DrawPrimitive(D3DPT_LINELIST, 0, NV);
    pDirect3DDevice->EndScene();

   pDirect3DDevice->Present(NULL, NULL, NULL, NULL);

   return S_OK;
}

void DeleteDirect3D()
{
   if(pVertexBuffer)
       pVertexBuffer->Release();
   if(pDirect3DDevice)
       pDirect3DDevice->Release();
   if(pDirect3D)
       pDirect3D->Release();
}

HRESULT InitialVertexBuffer()
{
    float u = 0.0;
    int z = 0;
    float points[][2] = {
        {150,150},
        {125,100},
        {150,50},
        {200,50},
        {225,55},
        {285,60},
        {325,25},
        
        {342,30},
        {340,35},
        {340,40},
    
        {325,75},
        {300,125},
        {300,175},
        {305,250},
        {295,287},
        {257,347},
        {200,350},
        {150,325},
        {140,290},

        {142,282},
        {160,280},
        {165,286},
        
        {175,325},
        {215,340},
        {250,335},
        {275,300},
        {275,250},
        {255,200},
        {250,150},
        {275,100},
        {305,65},
        
        {275,85},
        {240,95},
        {215,85},
        {170,65},
        {140,90},
        {160,135},

        {160,150},
        {152.5,150},
        {150,150}
    };
        
    CUSTOMVERTEX Vertexes[NV*2];
    int i = 0;
    while( i < NV*2 )
    {
        u = 0.f;
        for(int j = 0; j < segment; j++)
        {
            Vertexes[i].x = (1-3*u+3*u*u-u*u*u)*points[z][0]+(3*u-6*u*u+3*u*u*u)*points[z+1][0]+(3*u*u-3*u*u*u)*points[z+2][0]+(u*u*u)*points[z+3][0];
            Vertexes[i].y = (1-3*u+3*u*u-u*u*u)*points[z][1]+(3*u-6*u*u+3*u*u*u)*points[z+1][1]+(3*u*u-3*u*u*u)*points[z+2][1]+(u*u*u)*points[z+3][1];
            Vertexes[i].z = 0.5f;
            Vertexes[i].color = 0x00ffffff;
            Vertexes[i].rhv = 1.f;
            u += (float)1/segment;
            i++;
            Vertexes[i].x = (1-3*u+3*u*u-u*u*u)*points[z][0]+(3*u-6*u*u+3*u*u*u)*points[z+1][0]+(3*u*u-3*u*u*u)*points[z+2][0]+(u*u*u)*points[z+3][0];
            Vertexes[i].y = (1-3*u+3*u*u-u*u*u)*points[z][1]+(3*u-6*u*u+3*u*u*u)*points[z+1][1]+(3*u*u-3*u*u*u)*points[z+2][1]+(u*u*u)*points[z+3][1];
            Vertexes[i].z = 0.5f;
            Vertexes[i].color = 0x00ffffff;
            Vertexes[i].rhv = 1.f;
            i++;
        }
        z += 3;
    }
        if(FAILED(pDirect3DDevice->CreateVertexBuffer(NV*2*sizeof(CUSTOMVERTEX), 0, D3DFVF_CUSTOMVERTEX,
        D3DPOOL_DEFAULT, &pVertexBuffer, NULL)))
            return E_FAIL;
   
   void *pVB=NULL;
   if(FAILED(pVertexBuffer->Lock(0, sizeof Vertexes, (void**)&pVB, 0)))
      return E_FAIL;

   memcpy(pVB, Vertexes, sizeof Vertexes);
   
   pVertexBuffer->Unlock();
   
   return S_OK;
}

LRESULT CALLBACK MainWinProc(HWND hwnd, 
                             UINT msg,
                             WPARAM wparam, 
                             LPARAM lparam) 
{
   switch(msg)
   {
      case WM_PAINT:
            RenderingDirect3D();
            ValidateRect(hwnd, NULL);
            break;
      case WM_DESTROY:
            DeleteDirect3D();
            PostQuitMessage(0);
            return 0;
   }
   return DefWindowProc(hwnd, msg, wparam, lparam);
}

int WINAPI WinMain(HINSTANCE hinstance,
                   HINSTANCE hprevinstance,
                   LPSTR lpcmdline, 
                   int ncmdshow) 
{
   WNDCLASSEX windowsclass;
   HWND hwnd; 
   MSG msg; 
   //
   windowsclass.cbSize=sizeof(WNDCLASSEX);
   windowsclass.style=CS_DBLCLKS|CS_OWNDC|CS_HREDRAW|CS_VREDRAW;
   windowsclass.lpfnWndProc=MainWinProc;
   windowsclass.cbClsExtra=0;
   windowsclass.cbWndExtra=0;
   windowsclass.hInstance=hinstance;
   windowsclass.hIcon=LoadIcon(NULL, IDI_APPLICATION);
   windowsclass.hCursor=LoadCursor(NULL, IDC_ARROW);
   windowsclass.hbrBackground=(HBRUSH)GetStockObject(GRAY_BRUSH);
   windowsclass.lpszMenuName=NULL;
   windowsclass.lpszClassName=_T("WINDOWSCLASS");
   windowsclass.hIconSm=LoadIcon(NULL, IDI_APPLICATION);
   
   if(!RegisterClassEx(&windowsclass))
      return 0;
   
   if(!(hwnd=CreateWindowEx(
      NULL,
      _T("WINDOWSCLASS"), 
      _T("Desenam litera G"), 
      WS_OVERLAPPEDWINDOW|WS_VISIBLE, 
      CW_USEDEFAULT, 0, 
      CW_USEDEFAULT, 0, 
      NULL, 
      NULL, 
      hinstance, 
      NULL))) 
      return 0;

   if(SUCCEEDED(InitialDirect3D(hwnd)))
   {
      if(SUCCEEDED(InitialVertexBuffer()))
      {
         ShowWindow(hwnd, SW_SHOWDEFAULT); 
         UpdateWindow(hwnd); 
         ZeroMemory(&msg, sizeof msg);
         while(msg.message!=WM_QUIT)
         {
            if(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
            {
               TranslateMessage(&msg);
               DispatchMessage(&msg);
            }
            else
               RenderingDirect3D();
         }
      }
   }

   return msg.wParam;
}

Answer 1

Check project configuration. Linker->System->SubSystem should be Windows.