c++ - 当用于 Windproc 内部的参数时，HWND 地址会发生变化

Question

我试图创建一个函数createscalingwindow，它调用CreateWindowEx并将CreateWindowEx中使用的HWND的地址写入 vector ，然后通过它的初始大小和位置值。

我制作的另一个函数名为 scalewindowsize ，它应该采用两个给定的窗口并缩放一个窗口与另一个窗口的大小，但目前我什至无法匹配某些 HWND 的地址，因为在某些情况下在某些情况下，传递给scalewindowsize的HWND地址将与初始化时的地址完全不同。仅当我从窗口过程中调用 scalewindowsize 时，才会发生这种情况，并且在窗口过程的参数中使用与 scalewindowsize 参数中使用的 HWND 相同的 HWND。下面是相关代码:

#include <windows.h>
#include <stdio.h>
#include <winsock.h>
#include <vector>
#define ID_1 1000
#define ID_2 1001
#define ID_3 1002
HWND mainwin;  
HWND lobbywin;
int zero = 0;
char MENU1;
std::vector<intptr_t> sizevalues;
LRESULT CALLBACK mainproc (HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK lobbyproc (HWND, UINT, WPARAM, LPARAM);
char mainclassname[] = "main";
char lobbyclassname[] = "lobby";

void createscalingwindow(HWND &cswpara0,DWORD cswpara1,const CHAR* cswpara2,
const CHAR* cswpara3,DWORD cswpara4,int cswpara5,int cswpara6,int cswpara7,
int cswpara8,HWND cswpara9,HMENU cswpara10,HINSTANCE cswpara11,LPVOID cswpara12)
{
  cswpara0 = CreateWindowEx (cswpara1, cswpara2, cswpara3, cswpara4,cswpara5,
  cswpara6,cswpara7,cswpara8,cswpara9,cswpara10,cswpara11,cswpara12);
  char buffer[100];
  sizevalues.push_back((intptr_t)&cswpara0);
  snprintf (buffer, 20,"%d", sizevalues[zero]);
  MessageBox (NULL, buffer, "initialized", NULL);
  zero = (zero + 1);
  return;
}         

void scalewindowsize (HWND &ownerwin, const CHAR* tryz)
{
  char buffer[100];
  int checknumber = 0; 
  while (checknumber < sizevalues.size())
  {
    int compare = sizevalues[checknumber];
    if (sizevalues[checknumber] == (intptr_t)&ownerwin)
    {
      snprintf (buffer, 100,"%d", (intptr_t)&ownerwin);
      MessageBox (NULL, buffer, "value found", NULL);
      break;
    }
    else 
    {
      snprintf (buffer, 100,"%d", (intptr_t)&ownerwin);
      MessageBox (NULL, buffer, tryz, NULL);
      snprintf (buffer, 100,"%d", sizevalues[checknumber]);
      checknumber = (checknumber + 1);
      MessageBox (NULL, buffer, "fail currentcheck", NULL);
    }
  }
  return;
}

int WINAPI WinMain (HINSTANCE hThisInstance, HINSTANCE hPrevInstance,
LPSTR lpszArgument, int nCmdShow)
{
  MSG messages; 
  WNDCLASSEX mainwinclass;
  mainwinclass.hInstance = hThisInstance;
  mainwinclass.lpszClassName = mainclassname;
  mainwinclass.lpfnWndProc = mainproc;
  mainwinclass.style = CS_DBLCLKS;
  mainwinclass.cbSize = sizeof (WNDCLASSEX);
  mainwinclass.hIcon = LoadIcon (NULL, IDI_APPLICATION);
  mainwinclass.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
  mainwinclass.hCursor = LoadCursor (NULL, IDC_ARROW);
  mainwinclass.lpszMenuName = NULL;
  mainwinclass.cbClsExtra = 0;
  mainwinclass.cbWndExtra = 0;
  mainwinclass.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
  if (!RegisterClassEx (&mainwinclass))
   return 0;

  WNDCLASSEX lobbywinclass;        
  lobbywinclass.hInstance = hThisInstance;
  lobbywinclass.lpszClassName = lobbyclassname;
  lobbywinclass.lpfnWndProc = lobbyproc;    
  lobbywinclass.style = CS_DBLCLKS;                
  lobbywinclass.cbSize = sizeof (WNDCLASSEX);
  lobbywinclass.hIcon = LoadIcon (NULL, IDI_APPLICATION);
  lobbywinclass.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
  lobbywinclass.hCursor = LoadCursor (NULL, IDC_ARROW);
  lobbywinclass.lpszMenuName = NULL;                 
  lobbywinclass.cbClsExtra = 0;                     
  lobbywinclass.cbWndExtra = 0;                      
  lobbywinclass.hbrBackground = (HBRUSH) COLOR_BACKGROUND;


  if (!RegisterClassEx (&lobbywinclass))
   return 0;
  HMENU playmenu = CreateMenu();
  HMENU playmenulist = CreatePopupMenu();
  HMENU helpmenulist = CreatePopupMenu();
  AppendMenu(playmenulist, MF_STRING, ID_1, "Join game");
  AppendMenu(playmenulist, MF_STRING, ID_3, "Host game");
  AppendMenu(playmenulist, MF_STRING, ID_2, "Quit");
  InsertMenu(playmenu, 1, MF_POPUP|MF_BYPOSITION, (UINT_PTR)playmenulist, "Play");

  createscalingwindow(mainwin, 0, mainclassname, "mainwindow",
  WS_OVERLAPPED|WS_CAPTION|WS_THICKFRAME|WS_MINIMIZEBOX|WS_MAXIMIZEBOX|WS_SYSMENU, 
  CW_USEDEFAULT, CW_USEDEFAULT, 544, 375, NULL, playmenu, hThisInstance, NULL);
  ShowWindow (mainwin, nCmdShow);

  createscalingwindow(lobbywin, 0, lobbyclassname, "Lobby", WS_OVERLAPPEDWINDOW,
  CW_USEDEFAULT, CW_USEDEFAULT, 600, 425, NULL, NULL, hThisInstance, NULL);

  while (GetMessage (&messages, NULL, 0, 0))
  {
    TranslateMessage(&messages);
    DispatchMessage(&messages);
  }
  return messages.wParam;
}

LRESULT CALLBACK mainproc(HWND mainwin, UINT message, WPARAM wParam, LPARAM lParam)
{
  switch (message)         
  {
    case WM_SIZE:
    {
      scalewindowsize (mainwin, "mainwin");
      scalewindowsize (lobbywin, "lobbywin");
      break;
    }
    case WM_DESTROY:
    PostQuitMessage(0);
    break;
  } 
  switch (wParam)
  {
    case ID_3:
    EnableWindow (mainwin, false);
    ShowWindow (mainwin, false);
    ShowWindow (lobbywin, true);              
    break;
    default:  
    return DefWindowProc (mainwin, message, wParam, lParam); 
    break;
  }  
  return 0;
}    
LRESULT CALLBACK lobbyproc(HWND lobbywin, UINT message, WPARAM wParam, LPARAM lParam)
{
  switch (message)
  {
    case WM_SIZE:
    {
      scalewindowsize (mainwin, "mainwin");
      scalewindowsize (lobbywin, "lobbywin");
      break;
    }
    break;
  }
  switch (wParam)
  {
    case SC_CLOSE:
    {
      EnableWindow (mainwin, true);
      ShowWindow (mainwin, true);
      ShowWindow (lobbywin, false);
      EnableWindow (lobbywin, false);
      break;
    }
    default:
    return DefWindowProc (lobbywin, message, wParam, lParam);
    break;
  }
}

如果我运行此程序，单击主机游戏，返回主窗口并稍微调整其大小(在 mainrpoc 中设置 case WM_SIZE: )，然后退出程序，我会按时间顺序收到以下消息框:

1[title: Initialized |text: 4231184]
2[title: mainwin |text: 2292968]
3[title: fail currentcheck |text: 4231184]
4[title: lobbywin |text: 4231188]
5[title: fail currentcheck |text: 4231184]
6[title: initialized |text: 4231188] (no more boxes until I click on host game)
7[title: value found: |text: 4231184]
8[title: lobbywin |text: 2292676]
9[title: fail currentcheck |text: 4231184]
10[title: lobbywin |text: 2292676]
11[title: fail currentcheck |text: 4231188] (no more boxes until I go back to the mainwindow and resize it slightly)
12[title: mainwin |text: 2291164]
13[title: fail currentcheck |text: 4231184]
14[title: mainwin |text: 2291164]
15[title: fail currentcheck |text: 4231188]
16[title: lobbywin |text: 4231188]
17[title: fail currentcheck |text: 4231184]
18[title: value found |text: 4231188]

我现在很困惑，我希望阅读本文的人可以向我解释为什么地址会改变，提前感谢您花时间阅读我的问题。

更新:对于正在阅读本文的任何人，除了 whoz craigs 的回答之外，我还想添加一点:在 C++ 中调用全局变量而不是本地变量的方法是在变量之前添加::。

Answer 1

在两个窗口过程中，您都将参数 HWND 发送到scalewindow；不是全局的。因此它们是不同的地址。名称解析使用“最接近的”变量，在这两种情况下都是 HWND 参数，而不是您尝试使用的 HWND 全局变量。

示例:

LRESULT CALLBACK mainproc(HWND mainwin, UINT message, WPARAM wParam, LPARAM lParam)
{
  switch (message)         
  {
    case WM_SIZE:
    {
      scalewindowsize (mainwin, "mainwin");   // passes parameter mainwin by reference
      scalewindowsize (lobbywin, "lobbywin"); // passes global lobbywin by reference
      break;
    }

因此，引用将具有不同的地址解析。另一个例子:

LRESULT CALLBACK lobbyproc(HWND lobbywin, UINT message, WPARAM wParam, LPARAM lParam)
{
  switch (message)
  {
    case WM_SIZE:
    {
      scalewindowsize (mainwin, "mainwin");   // passes global mainwin by reference
      scalewindowsize (lobbywin, "lobbywin"); // passes parameter lobbywin by reference
      break;
    }
    break;