private void WriteSchemaWithFileStream(DataTable thisDataTable)
        {
            // Set the file path and name. Modify this for your purposes.
            string filename = "D:\\Schema.xml";

            // Create the FileStream object with the file name. 
            // Use FileMode.Create.
            System.IO.FileStream stream =
                new System.IO.FileStream(filename, System.IO.FileMode.Create);

            // Write the schema to the file.
            thisDataTable.WriteXmlSchema(stream);

            // Close the FileStream.
            stream.Close();
        }
        private void WriteSchemaWithFileStream(DataTable thisDataTable, bool writeHierarchy)
        {
            // Set the file path and name. Modify this for your purposes.
            string filename;
            if (writeHierarchy == false)
                 filename = "D:\\Schema1.xml";
            else
                 filename = "D:\\Schema2.xml";

            // Create the FileStream object with the file name. 
            // Use FileMode.Create.
            System.IO.FileStream stream =
                new System.IO.FileStream(filename, System.IO.FileMode.Create);

            // Write the schema to the file.
            thisDataTable.WriteXmlSchema(stream, writeHierarchy);

            // Close the FileStream.
            stream.Close();
        }
        [Test]
        public void TestWriteXmlSchema()
        {
            DataTable dt = new DataTable("TestWriteXmlSchema");
            dt.Columns.Add("Col1", typeof(int));
            dt.Columns.Add("Col2", typeof(int));
            DataRow dr = dt.NewRow();
            dr[0] = 10;
            dr[1] = 20;
            dt.Rows.Add (dr);
            DataTable dt1 = new DataTable("HelloWorld");
            dt1.Columns.Add("T1", typeof(int));
            dt1.Columns.Add("T2", typeof(int));
            DataRow dr1 = dt1.NewRow();
            dr1[0] = 10;
            dr1[1] = 20;
            dt1.Rows.Add(dr1);
            DataSet ds = new DataSet();
            ds.Tables.Add(dt);
            ds.Tables.Add(dt1);
            DataRelation rel = new DataRelation("Relation1", dt.Columns["Col1"], dt1.Columns["T1"]);
            ds.Relations.Add(rel);
            WriteSchemaWithFileStream(dt);
            WriteSchemaWithFileStream(dt, false);
            WriteSchemaWithFileStream(dt, true);
        }