我遇到了一些未解决的外部错误我似乎无法找到解决方案：
1>MyApp.obj : error LNK2019: unresolved external symbol "public: void __thiscall Path::AddPoint(struct Point2D const &)" (?AddPoint@Path@@QAEXABUPoint2D@@@Z) referenced in function "public: static long __stdcall MyApp::WndProc(struct HWND__ *,unsigned int,unsigned int,long)" (?WndProc@MyApp@@SGJPAUHWND__@@IIJ@Z)
1>MyApp.obj : error LNK2019: unresolved external symbol "public: void __thiscall Path::ClrPath(void)" (?ClrPath@Path@@QAEXXZ) referenced in function "public: static long __stdcall MyApp::WndProc(struct HWND__ *,unsigned int,unsigned int,long)" (?WndProc@MyApp@@SGJPAUHWND__@@IIJ@Z)
1>MyApp.obj : error LNK2019: unresolved external symbol "public: enum TOOL __thiscall Path::GetTool(void)" (?GetTool@Path@@QAE?AW4TOOL@@XZ) referenced in function "public: static long __stdcall MyApp::WndProc(struct HWND__ *,unsigned int,unsigned int,long)" (?WndProc@MyApp@@SGJPAUHWND__@@IIJ@Z)
1>MyApp.obj : error LNK2019: unresolved external symbol "public: void __thiscall Path::SetTool(enum TOOL)" (?SetTool@Path@@QAEXW4TOOL@@@Z) referenced in function "public: static long __stdcall MyApp::WndProc(struct HWND__ *,unsigned int,unsigned int,long)" (?WndProc@MyApp@@SGJPAUHWND__@@IIJ@Z)
奇怪的是，我很确定我正确地包含了一切。此外，总有一个函数适用于该类：DrawTo（）。
我尝试删除其他功能的“内联”声明，但似乎并不重要。
我还尝试重建一次，只需在两个函数之间添加一些额外的结束，然后编译！下次我尝试编译它时不再起作用......
所以我不完全确定我做错了什么，或者它是否是编译器...（默认VS2010编译器）（实际上，该编译器的名称是什么？[注释或编辑]）
有谁知道这可能意味着什么？
以下是相关代码:(如果您需要查看更多，评论和我将编辑）
#pragma once
#ifndef PATH_H
#define PATH_H
#include "Defines.h"
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include "MyVector.h"
#include "Point2D.h"
#include "Tool.h"
class Path
{
public:
Path();
virtual ~Path();
bool DrawTo(HDC hDC);
inline void AddPoint(const Point2D& rkPoint);
inline Point2D GetPointAt(int iIndex) const;
inline int GetPointCount() const;
inline TOOL GetTool();
inline void SetTool(TOOL t);
inline void SetColor1(COLORREF);
inline void SetColor2(COLORREF);
inline void ClrPath();
private:
MyVector<Point2D> m_PointVector;
TOOL m_Tool;
COLORREF m_Colour1;
COLORREF m_Colour2;
};
#endif
#include "Path.h"
Path::Path()
{
m_Tool = Tool_Pen;
m_Colour1 = RGB(0,0,0);
m_Colour2 = RGB(255,255,255);
}
Path::~Path()
{}
bool Path::DrawTo(HDC hDC)
{
if(hDC == NULL || m_PointVector.GetLength() <= 0) {
return false;
}
switch (m_Tool) {
case Tool_Pen:
{
//////
break;
}
case Tool_Line:
{
/////
break;
}
case Tool_Ellipse:
{
//////
break;
}
case Tool_Rectangle:
{
//////
break;
}
case Tool_LineTrack:
{
//////
break;
}
}
return true;
}
Point2D Path::GetPointAt(int iIndex) const {
return m_PointVector.At(iIndex);
}
int Path::GetPointCount() const {
return m_PointVector.GetLength();
}
void Path::AddPoint(const Point2D& rkPoint) {
m_PointVector.PushBack(rkPoint);
}
TOOL Path::GetTool() {
return m_Tool;
}
void Path::SetTool(TOOL t) {
m_Tool = t;
}
void Path::SetColor1(COLORREF col) {
m_Colour1 = col;
}
void Path::SetColor2(COLORREF col) {
m_Colour2 = col;
}
void Path::ClrPath() {
m_PointVector.ClrAll();
}
#pragma once
#ifndef MYAPP_H
#define MYAPP_H
#include "Defines.h"
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <string>
#include <iostream>
//app includes:
#include "MyHelperFuncs_Win32.h"
#include "BitmapPainter.h"
#include "Path.h"
//-------------
class MyApp
{
public:
MyApp();
virtual ~MyApp();
static LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
void Paint();
private:
void InitWindows();
HWND m_hWnd;
HDC m_hDC;
PAINTSTRUCT m_PaintStruct;
//app-specific:
BitmapPainter* m_pBitmapPainter;
Path* m_pPath;
//------------
};
#endif
LRESULT MyApp::WndProc(HWND hWnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
{
if(iMsg == WM_CREATE)
{
CREATESTRUCT *pCS = (CREATESTRUCT*)lParam;
SetWindowLongPtr(hWnd, GWLP_USERDATA, (LONG)pCS->lpCreateParams);
}
else
{
//retrieve the stored "this" pointer
MyApp* pApp = (MyApp*)GetWindowLongPtr(hWnd, GWLP_USERDATA);
switch (iMsg)
{
case WM_PAINT:
{
pApp->Paint();
return 0;
}
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
int wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_NEW:
{
//////
return 0;
case IDM_LOAD:
{
//////
return 0;
}
case IDM_SAVE:
{
//////
return 0;
}
case IDM_SAVEAS:
{
//////
return 0;
}
case IDM_EXIT:
{
DestroyWindow(hWnd);
return 0;
}
case IDM_COLOURMAIN:
{
//////
return 0;
}
case IDM_COLOURSECONDARY:
{
//////
return 0;
}
case IDM_PEN:
{
pApp->m_pPath->SetTool(Tool_Pen);
return 0;
}
case IDM_LINE:
{
pApp->m_pPath->SetTool(Tool_Line);
return 0;
}
case IDM_ELLIPSE:
{
pApp->m_pPath->SetTool(Tool_Ellipse);
return 0;
}
case IDM_RECTANGLE:
{
pApp->m_pPath->SetTool(Tool_Rectangle);
return 0;
}
case IDM_LINETRACK:
{
pApp->m_pPath->SetTool(Tool_LineTrack);
return 0;
}
default:
{
//////
return 0;
}
}
}
case WM_LBUTTONUP:
{
OutputDebugString(_T("Left Button Up\n "));
if(wParam & MK_CONTROL)OutputDebugString(_T("The CTRL key is down.\n "));
int x = LOWORD(lParam);
int y = HIWORD(lParam);
switch(pApp->m_pPath->GetTool()) {
case Tool_Pen:
{
pApp->m_pPath->DrawTo(pApp->m_hDC);
pApp->m_pPath->ClrPath();
InvalidateRect(pApp->m_hWnd,NULL,true);
}
}
return 0;
}
case WM_LBUTTONDOWN:
{
OutputDebugString(_T("Left Button Down\n "));
if(wParam & MK_CONTROL)OutputDebugString(_T("The CTRL key is down.\n "));
int x = LOWORD(lParam);
int y = HIWORD(lParam);
return 0;
}
case WM_RBUTTONUP:
{
OutputDebugString(_T("Right Button Up\n "));
if(wParam & MK_CONTROL)OutputDebugString(_T("The CTRL key is down.\n "));
int x = LOWORD(lParam);
int y = HIWORD(lParam);
return 0;
}
case WM_MOUSEMOVE:
{
OutputDebugString(_T("Mouse Moved\n "));
if(wParam & MK_CONTROL)OutputDebugString(_T("The CTRL key is down.\n "));
int x = LOWORD(lParam);
int y = HIWORD(lParam);
std::cout <<"Mouse Position: x=" << x << " y=" << y << "\n";
if (wParam & MK_LBUTTON) {
switch(pApp->m_pPath->GetTool()) {
case Tool_Pen:
{
Point2D p;
p.x = x;
p.y = y;
pApp->m_pPath->AddPoint(p);
InvalidateRect(pApp->m_hWnd,NULL,true);
}
}
}
return 0;
}
case WM_DESTROY:
{
PostQuitMessage(0);
return 0;
}
}
}
return DefWindowProc (hWnd, iMsg, wParam, lParam) ;
}
答案 0 :(得分：3)
取出那些“内联”声明（因为代码没有内联，除非它实际上在头文件中）。然后做一个干净的构建，然后完整构建。
答案 1 :(得分：2)
唯一有效的功能是没有内联的功能。
如果你仔细想想，你会意识到它是有道理的。当编译器正在编译MyApp.cpp时，它发现您正在调用声明为inline的方法。因此编译器需要复制该方法的代码而不是仅仅调用它。问题是，编译器如何知道定义该方法的位置？编译器可以看到的唯一方法是内联方法的实现是在Path.h中还是在MyApp.cpp包含的其他头文件中。
因此，最简单的解决方案是将所有这些内联方法的实现移动到Path.h文件中。