C# 中的 MathType (OLE)

Question

我正在尝试在 C# 应用程序中运行 MathType...在表单中使用 OLE 来表示方程/图像。

这就是我开始编写代码的方式。 我得到了数学类型方程的 CLSID 对象。我创建一个新实例并运行一个动词来启动数学类型。在我尝试设置或获取我拥有的 IDataItem 属性的数据之前，这很有效。

代码：

string progID = "Equation.DSMT4";
comRetVal= CLSIDFromProgID(progID, out eqContainerGUID);
Type t = Type.GetTypeFromProgID(progID); //ok-> MT6 Equation
Object instance = Activator.CreateInstance(t);

IDataObject oleDataObject = instance as IDataObject;
MTSDKDN.MathTypeSDK.IOleObject oleObject = instance as IDataObject;

//run verb Run For Conversion - I'm not sure what this verb does
oleObject.DoVerb(2, (IntPtr)0, activeSite, 0, (IntPtr)this.Handle, new MathTypeSDK.COMRECT());

//up to here everything is find

//Now say I want to put a MathML string into the IDataObject
//set format 
formatEtc.cfFormat = (Int16)dataFormatMathMLPres.Id; //<-this overflows. I verified that the only format that works is Presentation MAthML
formatEtc.dwAspect = System.Runtime.InteropServices.ComTypes.DVASPECT.DVASPECT_CONTENT;
formatEtc.lindex = -1;
formatEtc.ptd = (IntPtr)0;
formatEtc.tymed = TYMED.TYMED_HGLOBAL;

//set medium
ConnectSTGMEDIUM stgMedium = new ConnectSTGMEDIUM();
string mathEqn = "<math><mi>x</mi></math>";
stgMedium.unionmember = Marshal.StringToHGlobalAuto(mathEqn);
stgMedium.pUnkForRelease = 0;

//if now i write the equation to console from STGMEDIUM i see that after each char there is a null. Is this normal?

//now I try to set data in IDataObject and the OLE object
//I thought this set the data of the ole object to the MathML string I put in STGMEDIUM
oleDataObject.SetData(ref formatEtc, ref stgMedium, false);

应用程序现在因以下异常而崩溃：

System.Runtime.InteropServices.COMException 未处理 Message="无效的 FORMATETC 结构（来自 HRESULT 的异常：0x80040064 (DV_E_FORMATETC)）" Source="System" ErrorCode=-2147221404 StackTrace：位于 System.Runtime.InteropServices.ComTypes.IDataObject .GetData(FORMATETC&格式,STGMEDIUM&介质)

我不确定这意味着什么，但我认为这可能与 formatEtc.cfFormat = (Int16)dataFormatMathMLPres.Id; 因为该 ID 是 50000 并且不适合短整型（cfFormat 是短整型），因此它会溢出到类似 -15000 的值。

Answer 1

我通过将其从无符号值转换为有符号值解决了类似的问题。这意味着如果值 (dataFormatMathMLPres.Id) 大于 32767。请改用 (dataFormatMathMLPres.Id - 65536)。它适合签名短裤。