屏幕截圖的C++ CLI

Question

我已經看到了發生的截圖並保存爲JPG格式的following code，我已經成功地編譯並運行它作爲Win32控制檯應用程序，

但是，當我嘗試使用以下代碼放在一個windowsForm/CLI（也就是應該採取截圖按鈕）項目中，我得到了以下錯誤：

1>screenshoter.obj : warning LNK4248: unresolved typeref token (0100002C) for 'Gdiplus.GpCachedBitmap'; image may not run 
1>screenshoter.obj : error LNK2028: unresolved token (0A000017) "extern "C" int __stdcall ReleaseDC(struct HWND__ *,struct HDC__ *)" (?ReleaseDC@@$$J18YGHPAUHWND__@@PAUHDC__@@@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A000018) "extern "C" int __stdcall DeleteObject(void *)" (?DeleteObject@@$$J14YGHPAX@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A000019) "extern "C" int __stdcall BitBlt(struct HDC__ *,int,int,int,int,struct HDC__ *,int,int,unsigned long)" (?BitBlt@@$$J236YGHPAUHDC__@@HHHH0HHK@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A00001A) "extern "C" void * __stdcall SelectObject(struct HDC__ *,void *)" (?SelectObject@@$$J18YGPAXPAUHDC__@@PAX@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A00001B) "extern "C" struct HBITMAP__ * __stdcall CreateCompatibleBitmap(struct HDC__ *,int,int)" (?CreateCompatibleBitmap@@$$J212YGPAUHBITMAP__@@PAUHDC__@@HH@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A00001C) "extern "C" struct HDC__ * __stdcall CreateCompatibleDC(struct HDC__ *)" (?CreateCompatibleDC@@$$J14YGPAUHDC__@@PAU1@@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A00001D) "extern "C" int __stdcall GetSystemMetrics(int)" (?GetSystemMetrics@@$$J14YGHH@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2028: unresolved token (0A00001E) "extern "C" struct HDC__ * __stdcall GetDC(struct HWND__ *)" (?GetDC@@$$J14YGPAUHDC__@@PAUHWND__@@@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" int __stdcall ReleaseDC(struct HWND__ *,struct HDC__ *)" (?ReleaseDC@@$$J18YGHPAUHWND__@@PAUHDC__@@@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" int __stdcall DeleteObject(void *)" (?DeleteObject@@$$J14YGHPAX@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" int __stdcall BitBlt(struct HDC__ *,int,int,int,int,struct HDC__ *,int,int,unsigned long)" (?BitBlt@@$$J236YGHPAUHDC__@@HHHH0HHK@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" void * __stdcall SelectObject(struct HDC__ *,void *)" (?SelectObject@@$$J18YGPAXPAUHDC__@@PAX@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" struct HBITMAP__ * __stdcall CreateCompatibleBitmap(struct HDC__ *,int,int)" (?CreateCompatibleBitmap@@$$J212YGPAUHBITMAP__@@PAUHDC__@@HH@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" struct HDC__ * __stdcall CreateCompatibleDC(struct HDC__ *)" (?CreateCompatibleDC@@$$J14YGPAUHDC__@@PAU1@@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" int __stdcall GetSystemMetrics(int)" (?GetSystemMetrics@@$$J14YGHH@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 
1>screenshoter.obj : error LNK2019: unresolved external symbol "extern "C" struct HDC__ * __stdcall GetDC(struct HWND__ *)" (?GetDC@@$$J14YGPAUHDC__@@PAUHWND__@@@Z) referenced in function "private: void __clrcall screenshoter::Form1::gdiscreen(void)" (?gdiscreen@Form1@screenshoter@@$$FA$AAMXXZ) 

注：我已經列入需要

的所有文件我擡頭一看MSDN，但我真的不明白錯誤信息。此外，我過去曾遇到過類似的消息，我解決了這個問題，但是添加的.lib文件

這一次我嘗試添加，但它並沒有解決問題

#pragma comment(lib, "GdiPlus.lib") 

Answer 1

這些函數在gdi32.lib中聲明 - 不是gdiplus.lib - 有些可能在user32.lib中。

Answer 2

這些錯誤消息意味着你的代碼（或者說'screenshooter'代碼）使用了'symbols'（例如可能是函數名或變量），沒有代碼鏈接到最終的二進制文件中。

要解決這個問題，請查找每個符號需要鏈接的庫。例如，GetDC似乎是在user32.lib中定義的，所以請確保與該鏈接相關聯（可能通過使用#pragma指令，就像您對GdiPlus.lib所做的那樣）。