Serialization of DataColumn Type Corrected (#27286)

Author: Anipik

src/System.Data.Common/src/System/Data/DataTable.cs

@@ -372,8 +372,7 @@ internal void SerializeTableSchema(SerializationInfo info, StreamingContext cont
                 info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.DefaultValue", i), Columns[i].DefaultValue);
                 info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.ReadOnly", i), Columns[i].ReadOnly);
                 info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.MaxLength", i), Columns[i].MaxLength);
-                info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.DataType", i), Columns[i].DataType);
-
+                info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.DataType_AssemblyQualifiedName", i), Columns[i].DataType.AssemblyQualifiedName);
                 info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.XmlDataType", i), Columns[i].XmlDataType);
                 info.AddValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.SimpleType", i), Columns[i].SimpleType);
 
@@ -442,7 +441,8 @@ internal void DeserializeTableSchema(SerializationInfo info, StreamingContext co
                 dc._columnUri = info.GetString(string.Format(formatProvider, "DataTable.DataColumn_{0}.Namespace", i));
                 dc.Prefix = info.GetString(string.Format(formatProvider, "DataTable.DataColumn_{0}.Prefix", i));
 
-                dc.DataType = (Type)info.GetValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.DataType", i), typeof(Type));
+                string typeName = (string)info.GetValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.DataType_AssemblyQualifiedName", i), typeof(string));
+                dc.DataType = Type.GetType(typeName, throwOnError: true);
                 dc.XmlDataType = (string)info.GetValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.XmlDataType", i), typeof(string));
                 dc.SimpleType = (SimpleType)info.GetValue(string.Format(formatProvider, "DataTable.DataColumn_{0}.SimpleType", i), typeof(SimpleType));
 

src/System.Data.Common/tests/System/Data/DataTableTest.cs

@@ -32,6 +32,7 @@
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
+using System.Runtime.Serialization.Formatters.Binary;
 using System.Runtime.Serialization.Formatters.Tests;
 using System.Xml;
 using Xunit;
@@ -388,6 +389,25 @@ public void SelectOperators()
 
         }
 
+        [Fact]
+        public void DataColumnTypeSerialization()
+        {
+            DataTable dt = new DataTable("MyTable");
+            DataColumn dc = new DataColumn("dc", typeof(int));
+            dt.Columns.Add(dc);
+            dt.RemotingFormat = SerializationFormat.Binary;
+
+            DataTable dtDeserialized;
+            using (MemoryStream ms = new MemoryStream())
+            {
+                BinaryFormatter bf = new BinaryFormatter();
+                bf.Serialize(ms, dt);
+                ms.Seek(0, SeekOrigin.Begin);
+                dtDeserialized = (DataTable)bf.Deserialize(ms);
+            }
+            Assert.Equal(dc.DataType, dtDeserialized.Columns[0].DataType);
+        }
+
         [Fact]
         public void SelectExceptions()
         {