Returning Objects to UI

Returning Objects to UI

• jaimlin

  The following methods will add all public properties from all base classes of the type you wish to serialize using the XmlSerializer. Pass the returned XmlAttributeOverrides to the Serialize/Deserialize method.

  public static XmlAttributeOverrides IgnoreBaseClass(Type type)
  {
  if(type == null)
  throw new ArgumentNullException("type", "Type can't be null"); XmlAttributes attributes = new XmlAttributes();
  attributes.XmlIgnore = true;
  XmlAttributeOverrides overrides = new XmlAttributeOverrides();
  while(type.BaseType != null)
  {
  PropertyInfo[] properties = type.BaseType.GetProperties(BindingFlags.Public | BindingFlags.Instance);
  InsertMemberInfo(properties, overrides, type.BaseType, attributes);
  /*
  FieldInfo[] fields = type.BaseType.GetFields(BindingFlags.Public | BindingFlags.Instance);
  InsertMemberInfo(properties, overrides, type.BaseType, attributes);
  */
  type = type.BaseType;
  }
  return overrides;
  }
  private static void InsertMemberInfo(MemberInfo[] members, XmlAttributeOverrides overrides, Type type, XmlAttributes attributes) {
  foreach(MemberInfo member in members)
  {
  overrides.Add(type, member.Name, attributes);
  }
  }

  
  

• siaj

  HI.guy.

  the webservice also use XMLSerializer to Serialize the object return value or parameter passed to webmethod.

  if the object that would be serialized has any property which is a Interface type. the above error will be throwed.

  but , why you want to return component like "SQLConnection" etc.

  for WebService pattern. only data object be return. and if there are Interface type property , XmlIgnoreAttribute will be assigned to them to

  prevent them being serrialized.

  Matt.

  
  
  

• daaboots

  Along these lines, I have some XML I want to deserialize to objects. The object I want to deserialize to is derived from a Control. I've used the following code:

  XmlAttributes attribute = new XmlAttributes();
  attribute.XmlIgnore = true;
  // Ignore Site property of the control
  XmlAttributeOverrides ov = new XmlAttributeOverrides();
  ov.Add(typeof(Vehicle), "Site", attribute);
  XmlSerializer serializer = new XmlSerializer(typeof(VehicleCollection), ov);

  
  However, I still get the same exception saying "Cannot serialize member System.ComponentModel.Component.Site of type System.ComponentModel.ISite because it is an interface."
  

  
  

• littleflsh

  Hi Matt,

  Thanks a lot for you reply

  basically I was trying to understand the essence of a Webservice!

  I was thinking of a scenario where I have a Business object calling a web service to return an object that can be used (or perhaps cached) and then used again, so in case if I want to cache a SqlConnection object, can I do it within a webservice (I guess they are stateless)

  SQLConnection was just an example, what I was basically looking for was that can I return *any* object from within a webservice.

  also If I Implement an Interface within my Webservice class, will I get this error ,

  I donot have any properties in my Webservice

  Cheers

  n3sachde

  
  
  

• JustinCReid

  HI.

  to XmlSerializer , some special property would not be serialize , like interface , circle reference etc.

  if it happens, you can use XmlIgnoreAttribute to prevent those properties from being serialized.

  but ,if the properties were declared in base type and has not way to access the source code. you can use XmlAttributeOverrides class to override the XmlSerialization action.

  Matt.

  
  
  

• brohans

  hi.

  i mean , the property's type is inteface.

  
  
  

• Jason D. Camp

  I figured it out. It worked when I added the Site property of the Component class. Then I had problems with loads of other properties. Eventually I created a helper method to iterate all base types of the type I want to deserialize, GetProperties(BindingFlags.Public | BindingFlags.Instance) and added these to an XmlAttributeOverrides object with the XmlIgnore property set to true. Then added this object to the XmlSerializer. Works like a charm.
  

• NastyMatt

  HI. guy.

  if you have to get anyobject that have a interface type property. you can use XmlAttributeOverrides to Ignore the Interface type Property.

  
  XmlAttributeOverrides _overrides = new XmlAttributeOverrides();
  XmlAttributes _atrs = new XmlAttributes();
  _atrs.XmlIgnore = true;
  _overrides.Add(typeof(SampleClass),"<theInterfaceProperty>",_atrs);
  
  XmlSerializer _xs = new XmlSerializer(typeof(SampleClass),_overrides);
  System.IO.MemoryStream _ms = new System.IO.MemoryStream();
  _xs.Serialize(_ms,this);

  Matt.

  
  
  

• d kretz

  can you post a sample of how you did this I am trying to serialize a sqlcommand object.

  Dim attribute As XmlAttributes = New XmlAttributes

  attribute.XmlIgnore = True

  Dim XAO As XmlAttributeOverrides = New XmlAttributeOverrides()

  XAO.Add(GetType(System.ComponentModel.ISite), "System.ComponentModel.Component.Site", attribute)

  Dim Serializer As New Xml.Serialization.XmlSerializer(GetType(SqlClient.SqlCommand), XAO)

  I still get the error about not being able to serialize Isite

  
  

• Saroj K. Nanda

  Hi Matt

  I am being a little silly here but when you say "Interface Type Property" does that mean a property that is basically an implementation of a property defined in a Interface

  Cheers

  n3sachde

  
  
  
• Returning Objects to UI