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copied!<p>I have been able to pass a C# jagged array to C++ via an external Pinvoke method without using unsafe C# code as in the code sample below. But I still have my concerns regarding the GC in non-debug mode causing side undesirable side-effect. Here's the piece of test code (that works in debug mode):</p> <pre><code>[Test, Ignore] public void Test_JaggedArrayPInvoke() { var jaggedArray = new int[3][]; jaggedArray[0] = new int[1] { 9 }; jaggedArray[1] = new int[4] { 1, 2, 3, 8 }; jaggedArray[2] = new int[2] { 1, 2 }; //GCHandle mainHandle = GCHandle.Alloc(jaggedArray, GCHandleType.Pinned); //This does not work var pinnedHandles = new GCHandle[3]; var jaggedArrayPtrs = new IntPtr[3]; for (int i = 0; i < 3; i++) { pinnedHandles[i] = GCHandle.Alloc(jaggedArray[i], GCHandleType.Pinned); jaggedArrayPtrs[i] = pinnedHandles[i].AddrOfPinnedObject(); } var result = JaggedArrayPInvoke_TEST(jaggedArrayPtrs); Console.WriteLine(result); //returns 8 as it should. //mainHandle.Free(); for (int i = 0; i < 3; i++) { pinnedHandles[i].Free(); } } //The C++ test method: extern "C" __declspec(dllexport) int __stdcall JaggedArrayPInvoke_TEST(int** jaggedArray); __declspec(dllexport) int __stdcall JaggedArrayPInvoke_TEST(int** jaggedArray) { return jaggedArray[1][3]; } </code></pre> <p>If I was to uncomment the mainHandle part, I get an argument exception "Object contains non-primitive or non-blittable data". <strong>So is it possible to pin the jaggedArray and is it really needed?</strong> (I vaguely recall that GC in release mode may recollect memory already within methods if it is not used any longer.) I think though that turning the jaggedArray into a class field variable instead would make it safe from a GC perspective.</p>

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