public void TestCustomProperties() { POIXMLDocument wb = new XSSFWorkbook(); POIXMLProperties.CustomProperties customProps = wb.GetProperties().GetCustomProperties(); customProps.AddProperty("test-1", "string val"); customProps.AddProperty("test-2", 1974); customProps.AddProperty("test-3", 36.6); //Adding a duplicate try { customProps.AddProperty("test-3", 36.6); Assert.Fail("expected exception"); } catch (ArgumentException e) { Assert.AreEqual("A property with this name already exists in the custom properties", e.Message); } customProps.AddProperty("test-4", true); wb = (XSSFWorkbook)XSSFTestDataSamples.WriteOutAndReadBack((XSSFWorkbook)wb); CT_CustomProperties ctProps = wb.GetProperties().GetCustomProperties().GetUnderlyingProperties(); Assert.AreEqual(4, ctProps.sizeOfPropertyArray()); CT_Property p; p = ctProps.GetPropertyArray(0); Assert.AreEqual("{D5CDD505-2E9C-101B-9397-08002B2CF9AE}", p.fmtid); Assert.AreEqual("test-1", p.name); Assert.AreEqual("string val", p.Item.ToString()); Assert.AreEqual(2, p.pid); p = ctProps.GetPropertyArray(1); Assert.AreEqual("{D5CDD505-2E9C-101B-9397-08002B2CF9AE}", p.fmtid); Assert.AreEqual("test-2", p.name); Assert.AreEqual(1974, p.Item); Assert.AreEqual(3, p.pid); p = ctProps.GetPropertyArray(2); Assert.AreEqual("{D5CDD505-2E9C-101B-9397-08002B2CF9AE}", p.fmtid); Assert.AreEqual("test-3", p.name); Assert.AreEqual(36.6, p.Item); Assert.AreEqual(4, p.pid); p = ctProps.GetPropertyArray(3); Assert.AreEqual("{D5CDD505-2E9C-101B-9397-08002B2CF9AE}", p.fmtid); Assert.AreEqual("test-4", p.name); Assert.AreEqual(true, p.Item); Assert.AreEqual(5, p.pid); }