借助qtwinmigrate，实现外部程序调用带QT界面的DLL

谁践踏了优雅 2022-12-11 02:29 185阅读 0赞

首先看GitHub提供的示例：

下载 qtwinmigrate：[https://github.com/qtproject/qt-solutions][https_github.com_qtproject_qt-solutions]  
如 github 无法下载，可使用: https://pan.baidu.com/s/1kG2WGMYb7hk6ppfMqhd8eQ 提取码: 34sh

解压，找到 \\qtwinmigrate\\examples\\qtdll\\qtdll.pro，使用QtCreator打开：

#include <qmfcapp.h>
    #include <qwinwidget.h>
    
    #include <QMessageBox>
    #include <windows.h>
    
    BOOL WINAPI DllMain( HINSTANCE hInstance, DWORD dwReason, LPVOID /*lpvReserved*/ )
    { 
        static bool ownApplication = FALSE;
    
        if ( dwReason == DLL_PROCESS_ATTACH )
    	ownApplication = QMfcApp::pluginInstance( hInstance );
        if ( dwReason == DLL_PROCESS_DETACH && ownApplication )
    	delete qApp;
    
        return TRUE;
    }
    
    extern "C" __declspec(dllexport) bool showDialog( HWND parent )
    { 
        QWinWidget win( parent );
        win.showCentered();
        QMessageBox::about( &win, "About QtMfc", "QtMfc Version 1.0\nCopyright (C) 2003" );
    
        return TRUE;
    }

编译后，生成qtdialog.dll

新建控制台程序（用来调用qtdialog.dll），代码如下：

#include <iostream>
    #include <Windows.h>
    using std::cout;
    using std::endl;
    typedef bool(*pShowDialog)(HWND parent);
    
    int main()
    { 
    	//center show
    	RECT rcDesk;
    	GetWindowRect(GetDesktopWindow(), &rcDesk);
    	RECT rc;
    	GetWindowRect(GetConsoleWindow(), &rc);
    	int x = rcDesk.left + (rcDesk.right - rcDesk.left) / 2 - (rc.right - rc.left) / 2;
    	int y = rcDesk.top + (rcDesk.bottom - rcDesk.top) / 2 - (rc.bottom - rc.top) / 2;
    	int cx = (rc.right - rc.left);
    	int cy = (rc.bottom - rc.top);
    	SetWindowPos(GetConsoleWindow(), NULL, x, y, cx, cy, SWP_NOSIZE);
    
        std::cout << "Hello World!\n";
    
    	const char* dllName = "qtdialog.dll";
    	HMODULE hDLL = LoadLibraryA(dllName);
    	if (hDLL != NULL)
    	{ 
    		//
    		pShowDialog fp = pShowDialog(GetProcAddress(hDLL, "ShowDialog"));
    		if (fp != NULL)
    		{ 
    			//ShowWindow(GetConsoleWindow(), SW_HIDE);
    			std::cout << "pShowDialog!\n";
    			fp(GetConsoleWindow());
    		}
    		//
    		FreeLibrary(hDLL);
    	}
    	else
    	{ 
    		cout << "Cannot Find " << dllName << endl;
    	}
    
    	system("pause");
    	return 0;
    }

使用 windeployqt 拉取 qtdialog.dll 所依赖的文件，并将其一同放置在控制台生成的目录下，运行控制台程序，即可看到控制台程序调起了qt的dll。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hlbGxva2FuZHk_size_16_color_FFFFFF_t_70_pic_center]  
如果需要在dll中开发自定义界面的，代码也很简单。比如说，开发一个专门用于选择文件路径的dll：

extern "C" __declspec(dllexport) bool ShowDirDialog(HWND parent)
    { 
    	QWinWidget win(parent);
    	win.center();
    	QtDirDlg dlg(&win);
    	dlg.exec();
    
    	return TRUE;
    }

[https_github.com_qtproject_qt-solutions]: https://github.com/qtproject/qt-solutions
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2hlbGxva2FuZHk_size_16_color_FFFFFF_t_70_pic_center]: /images/20221123/2ba31187b9f04a71b9308e24326dd914.png