Try something like this, if you want a single string (not tested): int byteLength = Marshal.SizeOf(Of IntPtr); IntPtr intPtr = Marshal.AllocHGlobal(byteLength);
H5A.read(attributeId, attributeTypeId, intPtr); string result = Marshal.PtrToStringAnsi(intPtr); If you want a more general way to read multiple strings at once, the code must be modified slightly. Best regards, Vincent Von: Hdf-forum [mailto:hdf-forum-boun...@lists.hdfgroup.org] Im Auftrag von Gerd Heber Gesendet: Donnerstag, 30. März 2017 16:58 An: HDF Users Discussion List <hdf-forum@lists.hdfgroup.org> Betreff: Re: [Hdf-forum] Reading VLEN string attribute values. What’s the storage layout of the attribute? (i.e., is it H5S_SIMPLE or H5S_SCALAR?) G. From: Hdf-forum [mailto:hdf-forum-boun...@lists.hdfgroup.org] On Behalf Of Matt Wood Sent: Thursday, March 30, 2017 9:42 AM To: hdf-forum@lists.hdfgroup.org<mailto:hdf-forum@lists.hdfgroup.org> Subject: [Hdf-forum] Reading VLEN string attribute values. Hi, I am using HDF.PInvoke 1.10.0.4 but I am struggling to read the string value of an attribute when it is variable length. Ultimately I believe I need to call: GCHandle hnd = GCHandle.Alloc(data, GCHandleType.Pinned); int err = H5A.read(aid, typeId, hnd.AddrOfPinnedObject()); hnd.Free(); Where data is a suitable object. I am confident that the attribute id (aid) is correct because it works for all the other attributes types. I am not so confident on the typeId, I have tried: H5T.get_type(aid); * H5T.get_native_type(tid); H5T.create(H5T.class_t.VLEN, H5T.VARIABLE); H5T.create(H5T.class_t.STRING, H5T.VARIABLE); Likewise for the data and I have tried: * data = new byte[256]; data = new IntPtr[1]; => data[0] = GCHandle.Alloc(byte[256], GCHandleType.Pinned).AddrOfPinnedObject() The only time some non-zero values were returned was case (*) but then I couldn't relate the values to the expected text. Thanks, Matt
_______________________________________________ Hdf-forum is for HDF software users discussion. Hdf-forum@lists.hdfgroup.org http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5
