使用数值计算库Zero - VC6调用失败、cfree调用成功

你的名字 2023-01-08 10:28 130阅读 0赞

Zero是一个功能丰富的C++数值计算库，具有复数、向量、矩阵等类，具备求根,拟合,插值,积分,随机数,统计,全局和局部的约束以及无约束优化,常微分方程求解等多项功能。

先下载一份Zero；看一下，有dll，手册，还有libZero.dll.a文件；有gcc的库文件，没有VC++的库文件（lib）；

先用VC6调用一下；

先下载一个由DLL生成lib文件的工具，生成lib文件看一下；

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JjYm9ibzIxY24_size_16_color_FFFFFF_t_70][]

生成一个lib文件；

生成一个单文档工程；项目做如下设置；先拷贝lib文件到项目；

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JjYm9ibzIxY24_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JjYm9ibzIxY24_size_16_color_FFFFFF_t_70 2][]

Zero.dll拷贝到exe目录；项目要包含zero提供的头文件，下载来就有；

OnDraw函数代码如下；

void CTestzeroView::OnDraw(CDC* pDC)
    {
    	CTestzeroDoc* pDoc = GetDocument();
    	ASSERT_VALID(pDoc);
    	// TODO: add draw code for native data here
    	CString str1;
    	Complex a1,a2,a3;
    	a1.setReal(10.0);
    	a1.setImag(5.0); //虚数,imaginary number
    	a2.setReal(6.0);
    	a2.setImag(2.0);
    	a3 = a1-a2;
    	str1.Format("a3 is: %f + %f", a3.getReal(), a3.getImag());
    	pDC->TextOut(50,50,str1);
    }

然后构建；总是出这个错误；

error LNK2001: unresolved external symbol "public: virtual \_\_thiscall Complex::~Complex(void)" (??1Complex@@UAE@XZ)

可能是没有找到lib文件；

使用代码导入lib文件；

\#pragma comment(lib, "Zero.lib")

还是一样报LNK2001错误；

代码中应该找到了lib文件；因为如果随意改个不存在的lib文件名字，如： \#pragma comment(lib, "Zerodddd.lib")

则提示：    LINK : fatal error LNK1104: cannot open file "Zerodddd.lib"

那么到此有可能是，用工具生成的lib文件有问题；zero本身不提供lib文件；

如果采用动态调用dll方式，则比较麻烦；动态装入DLL，获取函数地址，然后调用的方式；因为zero的dll提供的是类；

下面用CFree看一下；主文件代码如下；要把它的头文件包含进来；

#include <windows.h>
    #include <stdio.h>
    #include "resource.h"
    #include "zero.h"
     
    LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
     
    HINSTANCE hInst;
    TCHAR szClassName[] = TEXT("zeroDemo");
    
    Complex a1,a2,a3;
     
    int WINAPI
    WinMain (HINSTANCE hThisInstance,
             HINSTANCE hPrevInstance,
             LPSTR lpszArgument,
             int nFunsterStil)
    {
        HWND hwnd;
        MSG messages;
        WNDCLASSEX wincl;
     
    	hInst = hThisInstance;
    	
        wincl.hInstance = hThisInstance;
        wincl.lpszClassName = szClassName;
        wincl.lpfnWndProc = WindowProcedure;
        wincl.style = CS_DBLCLKS;
        wincl.cbSize = sizeof (WNDCLASSEX);
     
        wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
        wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
        wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
        wincl.lpszMenuName = MAKEINTRESOURCE (IDC_TESTZERO2);
        wincl.cbClsExtra = 0;
        wincl.cbWndExtra = 0;
        wincl.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
     
        if (!RegisterClassEx (&wincl))
            return 0;
     
        hwnd = CreateWindowEx (
               0,
               szClassName,
               TEXT("zero示例"),
               WS_OVERLAPPEDWINDOW,
               CW_USEDEFAULT,
               CW_USEDEFAULT,
               400,
               400,
               HWND_DESKTOP,
               NULL,
               hThisInstance,
               NULL
               );
     
        ShowWindow (hwnd, nFunsterStil);
     
        while (GetMessage (&messages, NULL, 0, 0))
        {
            TranslateMessage(&messages);
            DispatchMessage(&messages);
        }
     
        return messages.wParam;
    }
     
    LRESULT CALLBACK
    WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
    	PAINTSTRUCT ps;
    	HDC hdc;
    	RECT rt;	
    	char szBuffer[100];		
    				
        switch (message)
        {
    			case WM_COMMAND:
        		switch (LOWORD(wParam))
        		{
    			case IDM_zero:		
    				hdc=GetDC(hwnd);
    				
    				a1.setReal(10.0);
    				a1.setImag(5.0); //虚数,imaginary number
    				a2.setReal(6.0);
    				a2.setImag(2.0);
    				a3 = a1-a2;
    
    				//wsprintf(szBuffer, "%d",a1.getReal());
    				sprintf(szBuffer,"a1:   %lf + %lf",a1.getReal(),a1.getImag());
    				TextOut(hdc,10,10,szBuffer,lstrlen(szBuffer));
    				sprintf(szBuffer,"a2:   %lf + %lf",a2.getReal(),a2.getImag());
    				TextOut(hdc,10,40,szBuffer,lstrlen(szBuffer));
    				sprintf(szBuffer,"a3=a1-a2:   %lf + %lf",a3.getReal(),a3.getImag());
    				TextOut(hdc,10,70,szBuffer,lstrlen(szBuffer));
    				break;
    		    case IDM_ABOUT:
    				MessageBox (hwnd, TEXT ("zeroDemo v1.0\nCopyright (C) 2020\n by bo"),
                            TEXT ("zeroDemo"), MB_OK | MB_ICONINFORMATION);
    				break;
    			case IDM_EXIT:
    				DestroyWindow(hwnd);
    				break;
    			default:
    				return DefWindowProc(hwnd, message, wParam, lParam);	    		
    		    }
        		break;
      		case WM_CREATE:
      			break;
        	case WM_PAINT:
    			hdc = BeginPaint(hwnd, &ps);					
    			GetClientRect(hwnd, &rt);				
    			EndPaint(hwnd, &ps);
    			break;
            case WM_DESTROY:
                PostQuitMessage (0);
                break;
            default:
                return DefWindowProc (hwnd, message, wParam, lParam);
        }
     
        return 0;
    }

如果做如下的设置；libZero.dll.a拷贝到exe目录，拷贝到CFree的库文件目录；dll拷贝到exe目录；

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JjYm9ibzIxY24_size_16_color_FFFFFF_t_70 3][]

则一直提示连接错误；

正在连接...  
\[Error\] C:\\PROGRA~2\\C-FREE~1\\mingw\\bin\\ld.exe: cannot find -llibZero.dll.a

配置为如下，则构建成功；

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JjYm9ibzIxY24_size_16_color_FFFFFF_t_70 4][]

然后运行程序，结果如下；

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2JjYm9ibzIxY24_size_16_color_FFFFFF_t_70 5][]

代码只是简单的调用一下它的复数类；定义2个复数并赋值实部和虚部；再计算复数相减的结果；它的复数类是可用的；

其他更多功能自己探索；

wsprintf不支持格式化浮点类型，改用sprintf，sprintf需要包含\#include <stdio.h>；

![202101192332352.png][]

#include "resource.h"
    #include <windows.h>
    
    /
    //
    // Menu
    //
    
    IDC_TESTZERO2 MENU 
    BEGIN
        POPUP "&File"
        BEGIN
        	MENUITEM "ZERO",                	IDM_zero
            MENUITEM "E&xit",                	IDM_EXIT
        END
        POPUP "&Help"
        BEGIN
            MENUITEM "&About ...",           	IDM_ABOUT
        END
    END

#define 	IDM_EXIT		10001
    #define 	IDM_ABOUT		10002
    
    #define 	IDC_TESTZERO2		10101
    #define 	IDD_ABOUTBOX	10102
    #define 	IDM_zero        40001

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[202101192332352.png]: /images/20221119/09a279df70844e6f9a0ae7ec074de6d6.png