可空类型亚音速2.2

Question

toxml用于打破（）当我打电话.ToXML()我得到的错误：

"There was an error reflecting type..."

我有一个可空类型。我该如何解决它？

Answer 1

亚音速论坛上有此线程，一个可能的解决方案：

http://forums.subsonicproject.com/forums/t/334.aspx

#region Overridden XML Serialization Logic 

    public override object NewFromXML(string xml) 
    { 
     System.Xml.XmlDocument xdoc = new System.Xml.XmlDocument(); 
     xdoc.LoadXml(xml); 
     object lObject = base.NewFromXML(xml); 
     PropertyInfo[] propertyInfos = lObject.GetType().GetProperties(); 
     foreach (PropertyInfo propertyInfo in propertyInfos) 
     { 
      if (propertyInfo == null) 
       continue; 
      if (propertyInfo.PropertyType.IsGenericType && propertyInfo.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))     
      { 
       if (xdoc.DocumentElement.Attributes[propertyInfo.Name] == null) 
        continue; 
       string textValue = xdoc.DocumentElement.Attributes[propertyInfo.Name].Value; 
       Type[] typeArgs = propertyInfo.PropertyType.GetGenericArguments(); 
       if (typeArgs == null || typeArgs.Length == 0) 
        continue; 
       object typedValue = GetTypedValue(textValue, typeArgs[0]); 
       propertyInfo.SetValue(lObject, typedValue, null); 
      } 
     } 
     return lObject; 
    } 

    private object GetTypedValue(string textValue, Type type) 
    { 
     if (string.IsNullOrEmpty(textValue)) 
      return null; 
     object typedValue = null; 
     if (type == typeof(DateTime)) 
      typedValue = Convert.ToDateTime(textValue); 
     else if (type == typeof(Byte)) 
      typedValue = Convert.ToByte(textValue); 
     else if (type == typeof(Int16)) 
      typedValue = Convert.ToInt16(textValue); 
     else if (type == typeof(Int32)) 
      typedValue = Convert.ToInt32(textValue); 
     else if (type == typeof(Int64)) 
      typedValue = Convert.ToUInt64(textValue); 
     else if (type == typeof(Double)) 
      typedValue = Convert.ToDouble(textValue); 
     else if (type == typeof(Single)) 
      typedValue = Convert.ToSingle(textValue); 
     else if (type == typeof(Boolean)) 
      typedValue = Convert.ToBoolean(textValue); 
     else if (type == typeof(Guid)) 
      typedValue = new Guid(textValue); 
     else 
      throw new NotImplementedException(string.Format("Conversion of type {0} from a string to a typed value is not implemented, yet. TextValue: {1}", type, textValue)); 
     return typedValue; 
    } 


    public override string ToXML() 
    { 
     string xml = base.ToXML(); 
     System.Xml.XmlDocument xdoc = new System.Xml.XmlDocument(); 
     xdoc.LoadXml(xml); 
     PropertyInfo[] propertyInfos = this.GetType().GetProperties(); 
     foreach (PropertyInfo propertyInfo in propertyInfos) 
     { 
      if (propertyInfo.PropertyType.IsGenericType && propertyInfo.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>)) 
      { 
       object val = propertyInfo.GetValue(this, null); 
       if (val == null) 
        continue; 
       XmlAttribute attribute = xdoc.CreateAttribute(propertyInfo.Name); 
       attribute.Value = val.ToString(); 
       xdoc.DocumentElement.Attributes.Append(attribute); 
       Console.WriteLine(propertyInfo.Name); 
      } 
     } 

     return xdoc.DocumentElement.OuterXml; 
    }   

    #endregion