Object of type 'Data.TimeLineChartedDay[]' cannot be converted to type 'Data.TimeLineChartedDay[]'?

I'm getting the following Designer Error in VS2008 :

 Object of type 'Data.TimeLineChartedDay[]' cannot be 
 converted to type 'Data.TimeLineChartedDay[]'.  

???

public class TimeLineDisplay     
{
    private List<TimeLineChartedDay> chartedDays = new List<TimeLineChartedDay>();

    public List<TimeLineChartedDay> ChartedDays         
    {
        get { return chartedDays; }
        set { chartedDays = value;  }
    }
}

[Serializable]
public class TimeLineChartedDay
{
    private DateTime date;
    private int chartValue;

    public DateTime Date
    {
        get { return date; }
        set { date = value; }
    }

    public int ChartValue
    {
        get { return chartValue; }
        set { chartValue = value; }
    }

    public TimeLineChartedDay()
    { 

    }
}

VS STACK :

    at System.RuntimeType.CheckValue(Object value, Binder binder, CultureInfo culture, BindingFlags invokeAttr)
    at System.Reflection.RtFieldInfo.InternalSetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, CultureInfo culture, Boolean doVisibilityCheck, Boolean doCheckConsistency)
    at System.Reflection.RtFieldInfo.InternalSetValue(Object obj, Object value, BindingFlags invokeAttr, Binder binder, CultureInfo culture, Boolean doVisibilityCheck)
    at System.Runtime.Serialization.FormatterServices.SerializationSetValue(MemberInfo fi, Object target, Object value)
    at System.Runtime.Serialization.ObjectManager.CompleteObject(ObjectHolder holder, Boolean bObjectFullyComplete)
    at System.Runtime.Serialization.ObjectManager.DoNewlyRegisteredObjectFixups(ObjectHolder holder)
    at System.Runtime.Serialization.ObjectManager.RegisterObject(Object obj, Int64 objectID, SerializationInfo info, Int64 idOfContainingObj, MemberInfo member, Int32[] arrayIndex)
    at System.Runtime.Serialization.Formatters.Binary.ObjectReader.RegisterObject(Object obj, ParseRecord pr, ParseRecord objectPr, Boolean bIsString)
    at System.Runtime.Serialization.Formatters.Binary.ObjectReader.ParseObjectEnd(ParseRecord pr)
    at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Parse(ParseRecord pr)
    at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run()
    at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
    at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage)
    at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream)
    at System.Resources.ResXDataNode.GenerateObjectFromDataNodeInfo(DataNodeInfo dataNodeInfo, ITypeRes开发者_Go百科olutionService typeResolver)
    at System.Resources.ResXDataNode.GetValue(ITypeResolutionService typeResolver)
    at System.Resources.ResXResourceReader.ParseDataNode(XmlTextReader reader, Boolean isMetaData)
    at System.Resources.ResXResourceReader.ParseXml(XmlTextReader reader)  

Previous to this error the following occured : I added a self written control. VS crashed with the following message: "Class TimeLineChartedDay is not marked as serializable". I found this strange because it was written on another machine, which didn't complain about the 'Serializable' attribute. I added the attribute to the class, and stumbled on the preivous mentioned error.

Your control is trying to serialize the class instance when it probably shouldn't.

You should probably add [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)] to the property that exposes the TimeLineDisplay.

For more specific advice, please show us your control.

I had the same problem with a custom control. Though adding the control via designer failed with the message "Class is not marked as serializable", it added a variable to the Designer.cs file and an entry the .resx file.

I had to remove those entries by hand and everything worked well. For the resx file I did right click -> Open with -> Source Editor and searched for entries containing the class name and removed them.

I had this problem with a Form containing a custom control. The custom control had a public property for a custom class X. (Class X was a simple DTO, serializable, and contained a default constructor.) The form designer displayed an error like:

"Object of type “X” cannot be converted to object of type “X”"

If you double click the forms .resx file, the resx designer will show all of the resources for the form. (note: in the upper left of the designer, there is a drop down to filter by resource type). The offending object appears as a line item (in my case, it was liste under type "other") Delete the line item and save all.