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POC# Define custom UnmanagedType for the MarshalAs attribute class
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copied!<p>is it possible to define a custom UnmanagedType for the MarshalAs attribute class? Specifically I want to convert a long int unix time into a DateTime type. Something like this:</p> <pre><code>[MarshalAs(UnmanagedType.LongTimeUnix)] public DateTime Time; </code></pre> <p>Where do I have to put the custom LongTimeUnix enumeration type and where to put the time conversion code:</p> <pre><code>public static DateTime ConvertUnix2DateTime(long timeStamp) { DateTime DT = new DateTime(1970, 1, 1, 0, 0, 0, 0); DT = DT.AddSeconds(timeStamp); return DT; } </code></pre> <p>When transferring the data with</p> <pre><code>(SomeStruct)Marshal.PtrToStructure( IntPtr, typeof(SomeStruct)); </code></pre> <p>I want that the long time unix is automatically converted with the code sinppet above. Do I have to inherit from the MarshalAs class and write the conversion into this class? Thanks, Juergen</p> <p><strong>Update</strong> Here is the custom marshaller:</p> <pre><code>class MarshalTest : ICustomMarshaler { public void CleanUpManagedData(object ManagedObj) { throw new NotImplementedException(); } public void CleanUpNativeData(IntPtr pNativeData) { throw new NotImplementedException(); } public int GetNativeDataSize() { return 8; } public IntPtr MarshalManagedToNative(object ManagedObj) { throw new NotImplementedException(); } public object MarshalNativeToManaged(IntPtr pNativeData) { long UnixTime = 0; try { UnixTime = Marshal.ReadInt64(pNativeData); } catch (Exception e) { QFXLogger.Error(e, "MarshalNativeToManaged"); } DateTime DT = new DateTime(1970, 1, 1, 0, 0, 0, 0); DT = DT.AddSeconds(UnixTime); return DT; } } </code></pre> <p>Here is the class definition:</p> <pre><code>unsafe public struct MT5ServerAttributes { /// <summary> /// Last known server time. /// </summary> [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(MarshalTest))] public DateTime CurrentTime; //[MarshalAs(UnmanagedType.U8)] [MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef = typeof(MarshalTest))] public DateTime TradeTime; } </code></pre> <p>And finally the code to marshal the data from unmanaged memory:</p> <pre><code>try { MT5ServerAttributes MT5SrvAttributes = (MT5ServerAttributes)Marshal.PtrToStructure(mMT5Proxy.MT5InformationProxy.ServerData, typeof(MT5ServerAttributes)); } catch (Exception e) { QFXLogger.Error(e, "ConsumeCommand inner"); } </code></pre> <p>When running this the following excpetion is thrown(which is not a direct exception ot PtrToStructure!) Cannot marshal field 'CurrentTime' of type 'QFX_DLL.MT5ServerAttributes': Invalid managed/unmanaged type combination (the DateTime class must be paired with Struct). Any ideas?</p>

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