标签：style blog class c code tar
在前面,我们看过OpenTK与MOgre,这二个项目都是C#项目,但是他的实现都是C++.他们简单来说就是一个包装层.常见的包装方式有二种,一种就是我们熟知的显式P/Invoke(DllImport),上面所说的OpenTK就是这种,还有一种就是C++ -> C++/CRL -> C#,这种也叫隐式P/Invoke,也有称C++ Interop,这篇文章主要讲的就是隐式P/Invoke,具体相关操作请见http://msdn.microsoft.com/zh-cn/library/2x8kf7zx.aspx .
1 #ifdef TRADITIONALDLL_EXPORTS 2 #define TRADITIONALDLL_API __declspec(dllexport) 3 #else 4 #define TRADITIONALDLL_API __declspec(dllimport) 5 #endif 6 7 extern "C" { 8 TRADITIONALDLL_API double GetDistance(Location, Location); 9 TRADITIONALDLL_API void InitLocation(Location*); 10 }
如上定义一个宏定义,在导出的C++动态链接库中,可以选择项目属性里添加预处理器定义TRADITIONALDLL_EXPORTS,也或者是在引用这个文件加上.而在引用这个动态链接库不做处理.
1 // C++ 2 TRADITIONALDLL_API int GetTestList(const unsigned long deviceId, char** confs, int& count, int& defaultID); 3 TRADITIONALDLL_API int GetTestList(const unsigned long deviceId, char** confs, int& count, int& defaultID) 4 { 5 auto tests = PApi->Spider_GetTestList(); 6 count = tests->count; 7 if (count > 0) 8 { 9 auto testNames = new char[32 * count]; 10 memset(testNames, 0, 32 * count); 11 for (int i = 0; i < count; i++) 12 { 13 memcpy(testNames + i * 32, tests->driveArray[i].TestName, 32); 14 } 15 *confs = testNames; 16 defaultID = PApi->curModule->nDefaultID; 17 return FUNC_SUCCESS; 18 } 19 spiderAPI->errorStr = NotConnecteDev; 20 return 0; 21 } 22 // managed C++ 23 bool GetTestList(const unsigned long deviceId, [Out]List <String^>^% testList, [Out]int% defalutID); 24 bool DeviceController::GetTestList(const unsigned long deviceId, [Out]List <String^>^% testList, [Out]int% defalutID) 25 { 26 testList = gcnew List<String^>(); 27 char *nameBuffer = NULL; 28 int testCount = 0; 29 int dID = 0; 30 ::GetTestList(deviceId, &nameBuffer, testCount, dID); 31 defalutID = dID; 32 if (nameBuffer != NULL && testCount > 0) 33 { 34 char testName[32]; 35 memset(testName, 0, 32); 36 for (int index = 0; index < testCount; ++index) 37 { 38 memcpy(testName, nameBuffer + index * 32, 32); 39 String^ str = gcnew String(testName); 40 testList->Add(str); 41 } 42 return true; 43 } 44 return false; 45 } 46 //C# 47 bool result = DeviceController.Instance.GetTestList(Device.Id, out testNames, out defaultID);
基本的传递如上,但是现在要求C#实时刷新设备转过来的数据,简单来说,就是C++里socket接收线程收到设备发送的数据,需要通知C#界面刷新.看需求,C#里的事件就能满足,但是是C++发送的消息,在这我们根据C++里的回调函数与托管代码里的事件结合来完成,去掉一些不必要的代码,主要过程如下.
1 // C++ 2 typedef void (__stdcall *OnDataMessageRev)(const unsigned long deviceId, char* data, const int eventId,const int p0, const int p1,const int p2); 3 4 class Module 5 { 6 OnDataMessageRev onDataRev; 7 void didDataReceived(); 8 void SetDataMessageCallback(OnDataMessageRev callback); 9 } 10 void Module::SetDataMessageCallback(OnDataMessageRev callback) 11 { 12 onDataRev = callback; 13 } 14 void Module::didDataReceived() 15 { 16 switch (dataMsg.Msg.nEventID) 17 { 18 case DSP_DISPNEXT_OK: 19 { 20 if (onDataRev) 21 onDataRev(this->deviceId, dataMsg.Data, dataMsg.Msg.nEventID, dataMsg.Msg.nParameters0, dataMsg.Msg.nParameters1, dataMsg.Msg.nParameters2); 22 } 23 break; 24 //... 25 } 26 } 27 DEVICEAPI_API void SetDataMessageCallback(OnDataMessageRev callback); 28 DEVICEAPI_API void SetDataMessageCallback(OnDataMessageRev callback) 29 { 30 model.SetDataMessageCallback(callback); 31 } 32 // managed C++ 33 public delegate void DeviceDataMessageHandler(const unsigned long deviceId, const array<Byte>^ data, const int eventId, const int p0, const int p1, const int p2); 34 public delegate void DeviceDataCallback(const unsigned long deviceId, char* data, const int eventId, const int p0, const int p1, const int p2); 35 public ref class DeviceController 36 { 37 DeviceDataCallback^ dataCallback; 38 DeviceDataMessageHandler^ onDeviceDataReceived; 39 event DeviceDataMessageHandler^ DeviceDataReceived 40 { 41 void add(DeviceDataMessageHandler^ h) 42 { 43 onDeviceDataReceived += h; 44 } 45 void remove(DeviceDataMessageHandler^ h) 46 { 47 onDeviceDataReceived -= h; 48 } 49 } 50 51 DeviceController::DeviceController() 52 { 53 dataCallback = gcnew DeviceDataCallback(&(DeviceController::DataReceivedCallback)); 54 IntPtr ptrData = Marshal::GetFunctionPointerForDelegate(dataCallback); 55 56 ::SetDataMessageCallback(static_cast<OnDataMessageRev>(ptrData.ToPointer())); 57 GC::KeepAlive(dataCallback); 58 } 59 60 void OnDeviceDataReceived(const unsigned long deviceId, const array<Byte>^ data, const int eventId, const int p0, const int p1, const int p2) 61 { 62 DeviceDataMessageHandler^ handler = onDeviceDataReceived; 63 if (handler != nullptr) 64 { 65 handler(deviceId, data, eventId, p0, p1, p2); 66 } 67 } 68 } 69 70 //C# 71 72 DeviceController.Instance.DeviceDataReceived += Instance_DeviceDataReceived; 73 74 T ByteArrayToStructure<T>(byte[] bytes, IntPtr pin, int offset) where T : struct 75 { 76 try 77 { 78 return (T)Marshal.PtrToStructure(pin + offset, typeof(T)); 79 } 80 catch (Exception e) 81 { 82 return default(T); 83 } 84 } 85 private void Instance_DeviceDataReceived(uint deviceId, byte[] data, int eventId, int p0, int p1, int p2) 86 { 87 GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned); 88 IntPtr pin = handle.AddrOfPinnedObject(); 89 int nCheckNum = ByteArrayToStructure<int>(data, pin, offset); 90 DISPLAYPARAMS displayParams = ByteArrayToStructure<DISPLAYPARAMS>(data, pin, offset); 91 VCSParamsDSP vcsPar = ByteArrayToStructure<VCSParamsDSP>(data, pin, offset); 92 handle.Free(); 93 94 }
C++里的memcyp确实很好用,上段代码中,ByteArrayToStructure也能实现如memcyp一样的功能,先用GCHandle.Alloc选择Pinned生成CG不能回改的内存区域,就和C++申请内存一样,然后根据偏移量offset,把对应的字节转成我们需要的数据.C++里的char和C#里的byte是一样的,都是一个字节,这里不要搞错了,也和C++一样,记的清除申请的内存空间.
实践:C++平台迁移以及如何用C#做C++包装层,布布扣,bubuko.com
标签：style blog class c code tar
原文地址：http://www.cnblogs.com/zhouxin/p/3738708.html
