How can I use a MemoryStream in a System.Generic.List<>

[mbudak]

I've object and it has a lot of objects :-\ When I access Childobjects everything is ok but not MemoryStreams;

public class myObject
{
public List<ChildObject> subObject = new List<ChildObject> { };

    public string ObjectName { get; set; }

    public class ChildObject
    {
        public string ChildObjectName { get; set; }
        public MemoryStream ChildStream { get; set; }
    }
}

When I use this object I am using following code;

// This is OK
MemoryStream myMS = new MemoryStream();
myMS.Position = 0;
// End of This is OK
//
myObject MyObj = new myObject();
MyObj.ObjectName = "My First Object";
MyObj.subObject.Add(new myObject.ChildObject());
MyObj.subObject[0].ChildObjectName = "My First Sub Object";
MyObj.subObject[0].ChildStream.Position = 0; // :mad:ERROR LINE

Thanks for your reply. :rolleyes:

[J4amieC]

:rolleyes: Indeed - you've not provided the error message you're getting. Hold on though - I'll use my psychic powers..... "Object reference not set to an instance of an object" ChildStream has not been instantiated.

MyObj.subObject[0].ChildObjectName = "My First Sub Object";
MyObj.subObject[0].ChildStream = new MemoryStream() // New Line
MyObj.subObject[0].ChildStream.Position = 0; // (NoLongerAn) ERROR LINE

[mbudak]

Impressive ;) Is it possible to auto create this MemoryStream in my subClass's constructor? When I Create following...

MyObj.subObject.Add(new myObject.ChildObject());

I want to use this MemoryStream directly. Thanks

[J4amieC]

Sure, just add a constructor to ChildObject and instantiate the memoryStream therein.

[mbudak]

Thanks for your help. This is work for me. Final solution as like these;

public class myObject
{
    public List<ChildObject> subObject = new List<ChildObject> { };

    public string ObjectName { get; set; }

    public class ChildObject
    {
        public string ChildObjectName { get; set; }
        public MemoryStream ChildStream { get; set; }

        public ChildObject()
        {
            ChildStream = new MemoryStream();
        }
        ~ChildObject()
        {
            ChildStream.Dispose();
        }
    }
}

[Mark Salsbery]

You may also want/need to implement IDisposable on your class to have more control over the lifetime of that stream (and it's associated memory). Mark

Mark Salsbery Microsoft MVP - Visual C++ :java: