serialize 2 objects to same xml file?

[vince]

Can I add (append) to an xml file that already contains a
serialized object, and be able to deserialize to either
or both objects from the same file...??? How is this
done...??

thanks,

vince

[Robert Jacobson]

> .... in microsoft.publi c.dotnet.genera l.

Correction: microsoft.publi c.dotnet.vb

[vince]

Robert,

tried your suggestion of putting the 2 serializable
objects into an Arraylist, and also an array of type
object[], but I get runtime errors... here's the code:

object[] jobArray = new object[2];

jobArray[0] = theJob; //serializable custom type w/
arraylist
jobArray[1] = myTask; //arraylist
XmlSerializer x2 = new XmlSerializer(t ypeof(object[]));
TextWriter tw = new StreamWriter("c :\\backup\\" +
textBox1.Text + ".xml");

x2.Serialize(tw , jobArray);

The exception thrown is "Job.JobFil e may not be used in
this context".... Job is the namespace, and theJob is an
object of type Job.JobFile.

Did the same thing using an Arraylist to hold the two
objects with similar results...

Thanks for any further suggestions... sorry for the
double post on newsgroups..

-----Original Message-----
Vince,

I replied to your question in microsoft.publi c.dotnet.genera l. In thefuture, please don't repost the same question to multiple groups.
There's no need to use strange workarounds to get this done. Just define anarray of objects (or ArrayList, or strongly-typed collection), place bothitems in the array, and serialize/deserialize the array. It will work fine.
--Robert Jacobson

"vince" <vl******@sdcer a.org> wrote in message
news:00******* *************** ******@phx.gbl. ..

Can I add (append) to an xml file that already contains a serialized object, and be able to deserialize to either
or both objects from the same file...??? How is this
done...??

thanks,

vince

.

[vince]

Robert,

I would also add that theJob seriailizes fine
individually, but I can't seem to get it to do so when
it's an element of a parent container...

thanks for your time...

vince

-----Original Message-----
Robert,

tried your suggestion of putting the 2 serializable
objects into an Arraylist, and also an array of type
object[], but I get runtime errors... here's the code:

object[] jobArray = new object[2];

jobArray[0] = theJob; //serializable custom type w/
arraylist
jobArray[1] = myTask; //arraylist
XmlSerialize r x2 = new XmlSerializer(t ypeof(object[]));
TextWriter tw = new StreamWriter("c :\\backup\\" +
textBox1.Tex t + ".xml");

x2.Serialize(t w, jobArray);

The exception thrown is "Job.JobFil e may not be used in
this context".... Job is the namespace, and theJob is an
object of type Job.JobFile.

Did the same thing using an Arraylist to hold the two
objects with similar results...

Thanks for any further suggestions... sorry for the
double post on newsgroups..

-----Original Message-----
Vince,

I replied to your question in

microsoft.publ ic.dotnet.gener al. In the

future, please don't repost the same question to

multiple groups.

There's no need to use strange workarounds to get this

done. Just define an

array of objects (or ArrayList, or strongly-typed

collection), place both

items in the array, and serialize/deserialize the

array. It will work fine.

--Robert Jacobson

"vince" <vl******@sdcer a.org> wrote in message
news:00****** *************** *******@phx.gbl ...

Can I add (append) to an xml file that alreadycontains a serialized object, and be able to deserialize to either or both objects from the same file...??? How is this
done...??

thanks,

vince

.

.

[Robert Jacobson]

You're right -- it turns out you can't just stuff an Object[] array with
custom classes and expect it to serailize correctly. The reason is that the
XmlSerializer is kind of dumb... it needs to know what type of object is
being stored in the array so that it can deserialize it correctly later on.
Sorry for leading you astray. <g>

The easiest way around this is to use a strongly-typed array or collection.
So, it should work if you replace the line "object[] jobArray = new
object[2];" with "jobFile[] jobArray = new jobFile[2];" I have some sample
code below. Alternatively, you could define a strongly-typed JobFile
collection by inheriting from CollectionBase.

Another alternative is to use the SOAP serializer or binary serializer
instead. Both are more robust than the XmlSerializer, and should be able to
serialize Object[] arrays correctly. The tradeoff is that the output from
those serializers are not as easily readable (for human eyes) than the clean
XML generated by the XmlSerailizer. Check out these articles:

http://msdn.microsoft.com/library/de...bjserializ.asp
http://msdn.microsoft.com/library/de...et09252001.asp

Hope this helps,
Robert Jacobson
using System;
using System.Xml.Seri alization;
using System.IO;
using System.Diagnost ics;

namespace ConsoleApplicat ion1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
SerializationTe st();
}

static void SerializationTe st()
{
Object[] jobArray = new Object[2];

DummyJob job1 = new DummyJob();
job1.Name = "First Job";
jobArray[0] = job1;

DummyJob job2 = new DummyJob();
job2.Name = "Second Job";
jobArray[1] = job2;

try
{

XmlSerializer serializer = new XmlSerializer(j obArray.GetType ());
StreamWriter sw = new StreamWriter("T est.xml");

serializer.Seri alize(sw, jobArray);
sw.Close();
}
catch (Exception ex)
{
Debug.WriteLine (ex.ToString()) ;
}
}
}

public class DummyJob
{
public string Name;
}

}
"vince" <vl******@sdcer a.org> wrote in message
news:02******** *************** *****@phx.gbl.. .

Robert,

I would also add that theJob seriailizes fine
individually, but I can't seem to get it to do so when
it's an element of a parent container...

thanks for your time...

vince

-----Original Message-----
Robert,

tried your suggestion of putting the 2 serializable
objects into an Arraylist, and also an array of type
object[], but I get runtime errors... here's the code:

object[] jobArray = new object[2];

jobArray[0] = theJob; //serializable custom type w/
arraylist
jobArray[1] = myTask; //arraylist
XmlSerialize r x2 = new XmlSerializer(t ypeof(object[]));
TextWriter tw = new StreamWriter("c :\\backup\\" +
textBox1.Tex t + ".xml");

x2.Serialize(t w, jobArray);

The exception thrown is "Job.JobFil e may not be used in
this context".... Job is the namespace, and theJob is an
object of type Job.JobFile.

Did the same thing using an Arraylist to hold the two
objects with similar results...

Thanks for any further suggestions... sorry for the
double post on newsgroups..

-----Original Message-----
Vince,

I replied to your question in

microsoft.publ ic.dotnet.gener al. In the

future, please don't repost the same question to

multiple groups.

There's no need to use strange workarounds to get this

done. Just define an

array of objects (or ArrayList, or strongly-typed

collection), place both

items in the array, and serialize/deserialize the

array. It will work fine.

--Robert Jacobson

"vince" <vl******@sdcer a.org> wrote in message
news:00****** *************** *******@phx.gbl ...
Can I add (append) to an xml file that already

contains a

serialized object, and be able to deserialize to either or both objects from the same file...??? How is this
done...??

thanks,

vince
.

.

[vince]

Robert,

thanks for your help, it seems that my custom JobFile
type can't be serialized as a member of a strongly typed
array... tried several ways of doing this, but Serialize()
keeps telliing me that my JobFile type "can't be used in
this context".

I suspect that it's because the JobFile class inherits
from ICollection and is set up to serialize a contained
arraylist of custom objects. I think I'm trying to do too
much here, will look at your other suggested methods.

Here's the code I was using:

JobFile[] jobArray = new JobFile[2];

jobArray[0] = theJob;
jobArray[1] = theJob1;

XmlSerializer x = new XmlSerializer(j obArray.GetType ());
TextWriter writer = new StreamWriter("c :\\backup\\" +
textBox1.Text + ".xml");
x.Serialize(wri ter, jobArray);

Thanks for your help,

Vince Lusardi

-----Original Message-----
You're right -- it turns out you can't just stuff an Object[] array withcustom classes and expect it to serailize correctly. The reason is that theXmlSerialize r is kind of dumb... it needs to know what type of object isbeing stored in the array so that it can deserialize it correctly later on.Sorry for leading you astray. <g>

The easiest way around this is to use a strongly-typed array or collection.So, it should work if you replace the line "object[] jobArray = newobject[2];" with "jobFile[] jobArray = new jobFile[2];" I have some samplecode below. Alternatively, you could define a strongly- typed JobFilecollection by inheriting from CollectionBase.

Another alternative is to use the SOAP serializer or binary serializerinstead. Both are more robust than the XmlSerializer, and should be able toserialize Object[] arrays correctly. The tradeoff is that the output fromthose serializers are not as easily readable (for human eyes) than the cleanXML generated by the XmlSerailizer. Check out these articles:
http://msdn.microsoft.com/library/default.asp? url=/library/en-us/dndotnet/html/objserializ.asphttp://msdn.microsoft.com/library/default.asp? url=/library/en-us/dnadvnet/html/vbnet09252001.a sp
Hope this helps,
Robert Jacobson
using System;
using System.Xml.Seri alization;
using System.IO;
using System.Diagnost ics;

namespace ConsoleApplicat ion1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
SerializationTe st();
}

static void SerializationTe st()
{
Object[] jobArray = new Object[2];

DummyJob job1 = new DummyJob();
job1.Name = "First Job";
jobArray[0] = job1;

DummyJob job2 = new DummyJob();
job2.Name = "Second Job";
jobArray[1] = job2;

try
{

XmlSerializer serializer = new XmlSerializer (jobArray.GetTy pe()); StreamWriter sw = new StreamWriter("T est.xml");

serializer.Seri alize(sw, jobArray);
sw.Close();
}
catch (Exception ex)
{
Debug.WriteLine (ex.ToString()) ;
}
}
}

public class DummyJob
{
public string Name;
}

}
"vince" <vl******@sdcer a.org> wrote in message
news:02******* *************** ******@phx.gbl. ..

Robert,

I would also add that theJob seriailizes fine
individually, but I can't seem to get it to do so when
it's an element of a parent container...

thanks for your time...

vince

>-----Original Message-----
>Robert,
>
>tried your suggestion of putting the 2 serializable
>objects into an Arraylist, and also an array of type
>object[], but I get runtime errors... here's the code:
>
>object[] jobArray = new object[2];
>
>jobArray[0] = theJob; //serializable custom type w/
>arraylist
>jobArray[1] = myTask; //arraylist
>XmlSerialize r x2 = new XmlSerializer(t ypeof(object [])); >TextWriter tw = new StreamWriter("c :\\backup\\" +
>textBox1.Tex t + ".xml");
>
>x2.Serialize(t w, jobArray);
>
>The exception thrown is "Job.JobFil e may not be used in >this context".... Job is the namespace, and theJob is an >object of type Job.JobFile.
>
>Did the same thing using an Arraylist to hold the two
>objects with similar results...
>
>Thanks for any further suggestions... sorry for the
>double post on newsgroups..
>
>
>>-----Original Message-----
>>Vince,
>>
>>I replied to your question in
>microsoft.publ ic.dotnet.gener al. In the
>>future, please don't repost the same question to
>multiple groups.
>>
>>There's no need to use strange workarounds to get this >done. Just define an
>>array of objects (or ArrayList, or strongly-typed
>collection), place both
>>items in the array, and serialize/deserialize the
>array. It will work fine.
>>
>>--Robert Jacobson
>>
>>
>>
>>
>>
>>"vince" <vl******@sdcer a.org> wrote in message
>>news:00****** *************** *******@phx.gbl ...
>>> Can I add (append) to an xml file that already
>contains a
>>> serialized object, and be able to deserialize to

either

>>> or both objects from the same file...??? How is this >>> done...??
>>>
>>> thanks,
>>>
>>> vince
>>
>>
>>.
>>
>.
>

.