用XmlSerializer（c＃）反序列化包含对象列表的类

Question

I'm trying to set up a very small database using XML serialization and more specifically XmlSerializer.

My main class is the following :

public class XmlDB
{
    [XmlIgnore]
    public string FilePath { get; private set; }


    public List<FooType> Foos { get; set; }
    public List<BarType> Bars { get; set; }
    public List<ThirdType> Thirds { get; set; }

    private XmlDB():this(null) { }

    public XmlDB(string strDBPath) {
        this.FilePath = strDBPath;
        this.Foos = new List<FooType>();
        this.Bars = new List<BarType>();
        this.Thirds = new List<ThirdType>();
    }

    public static XmlDB Load(string strDBPath) {
        using (XmlReader reader = XmlReader.Create(strDBPath)) {
            XmlDB db = (XmlDB)new XmlSerializer(typeof(XmlDB)).Deserialize(reader);
            db.FilePath = strDBPath;
            return db;
        }
    }

    public void SaveChanges() {
        XmlWriterSettings settings = new XmlWriterSettings() {
            Indent = true,
            Encoding = Encoding.UTF8
        };
        using (XmlWriter writer = XmlWriter.Create(this.FilePath, settings)) {
            XmlSerializer ser = new XmlSerializer(typeof(XmlDB));
            ser.Serialize(writer, this);
        }
    }
}

My test method creates an instance, populates the lists and calls the SaveChanges method. Everything works fine on serialization and the Xml output looks consistent.

The problem happens on deserializing : No error is reported but only the first item of the first List is treated, the following items of the first list are not deserialized, neither are the following lists...

If I shuffle the order of the lists in the Xml, it's always the first item of the first list in the Xml file that is deserialized.

I tried the following simple test to confirm (which unfortunately works fine, all lists are populated on deserializing) :

public class DBTestList
{
    public List<DBTest> TestList { get; set; }
    public List<DBTest2> TestList2 { get; set; }

    public DBTestList() {
        this.TestList = new List<DBTest>();
        this.TestList2 = new List<DBTest2>();
    }
}

public class DBTest
{
    public int TestInt { get; set; }
    public string TestStr { get; set; }
}

public class DBTest2
{
    public int TestInt { get; set; }
    public string TestStr { get; set; }
}

public void TestSerialProblem() {
    //Init data
    DBTestList tl = new DBTestList();
    tl.TestList.Add(new DBTest() { TestInt = 1, TestStr = "test11" });
    tl.TestList.Add(new DBTest() { TestInt = 2, TestStr = "test12" });
    tl.TestList2.Add(new DBTest2() { TestInt = 3, TestStr = "test21" });

    XmlWriterSettings settings = new XmlWriterSettings() {
        Indent = true,
        Encoding = Encoding.UTF8
    };
    using (XmlWriter writer = XmlWriter.Create("test.db", settings)) {
        XmlSerializer ser = new XmlSerializer(typeof(DBTestList));
        ser.Serialize(writer, tl);
    }

    using (XmlReader reader = XmlReader.Create("test.db")) {
        DBTestList db = (DBTestList)new XmlSerializer(typeof(DBTestList)).Deserialize(reader);
        Assert.IsTrue(db.TestList2[0].TestStr == "test21");
    }
}

I read a lot of posts on this subject but none helped. Do you have an idea ?

Thanks, Best regards.

EDIT : To give a more detailed idea of the classes used in the lists, here's one basic implementation. All the types are derived from the parent one a_SolidElement, adding only a few properties (basic value types and/or enum) :

public abstract class a_SolidElement
{
    [XmlIgnore]
    public int Position { get; set; }

    public virtual double Thickness { get; set; }
    public virtual double Density { get; set; }

    public string SupplierName { get; set; }
    public string Name { get; set; }
}

public enum ElementType
{
    Undefined=0,
    TypeA,
    TypeB
}

public class FooType:a_SolidElement
{
    public double AdditionalData { get; set; }

    public e_ElementType ElementType { get; set; }
}

Answer 1

dbc was actually right about the bad IXmlSerializable implementation in his comment : In one of my classes, I had one property of a type I didn't write, with a problem in the readXml method.

I didn't see it at first because I successively removed some properties to see which one caused the problem but this one was still in the first deserialized item so that even if the subsequent ones didn't have it, the reader was still already messed up by the first one.

It's so obvious now that I feel bad for asking the question in the first place !

Thank you very much for the help !