LINQ and XML for compact framework

**Jon Skeet [C# MVP]** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

<luowan@gmail.c omwrote:

<snip>

Is it because I am using compact framework? I've tested this code on
a normal framework. It is working fine.

That's very strange indeed - what line does the error message point at?

Could you post a short but complete program which demonstrates the
problem?

See http://www.pobox.com/~skeet/csharp/complete.html for details of
what I mean by that.

--
Jon Skeet - <skeet@pobox.co m>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On Apr 30, 7:52 pm, Jon Skeet [C# MVP] <sk...@pobox.co mwrote:

<luo...@gmail.c omwrote:
>
<snip>
>

Is it because I am using compact framework? I've tested this code on
a normal framework. It is working fine.

>
That's very strange indeed - what line does the error message point at?
>
Could you post a short but complete program which demonstrates the
problem?
>
Seehttp://www.pobox.com/~skeet/csharp/complete.htmlfo r details of
what I mean by that.
>
--
Jon Skeet - <sk...@pobox.co m>
Web site:http://www.pobox.com/~skeet
Blog:http://www.msmvps.com/jon.skeet
C# in Depth:http://csharpindepth.com

Actually it is not error, my program is still running. However, if I
place a break point at
IEnumerable<XEl ementmsgs = from el in
root.Descendant s("Message")
where el.Element("Mes sageID").Value ==
MsgID
select el;

After the statement is excuted, if I look up 'msgs' 's value, I will
get such error message.

**Jon Skeet [C# MVP]** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

Wan <luowan@gmail.c omwrote:

Actually it is not error, my program is still running. However, if I
place a break point at
IEnumerable<XEl ementmsgs = from el in
root.Descendant s("Message")
where el.Element("Mes sageID").Value ==
MsgID
select el;
>
>
After the statement is excuted, if I look up 'msgs' 's value, I will
get such error message.

In that case it sounds like a debugger problem rather than anything
else.

--
Jon Skeet - <skeet@pobox.co m>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On Apr 30, 9:46 pm, Jon Skeet [C# MVP] <sk...@pobox.co mwrote:

Wan <luo...@gmail.c omwrote:

Actually it is not error, my program is still running. However, if I
place a break point at
IEnumerable<XEl ementmsgs = from el in
root.Descendant s("Message")
where el.Element("Mes sageID").Value ==
MsgID
select el;

>

After the statement is excuted, if I look up 'msgs' 's value, I will
get such error message.

>
In that case it sounds like a debugger problem rather than anything
else.
>
--
Jon Skeet - <sk...@pobox.co m>
Web site:http://www.pobox.com/~skeet
Blog:http://www.msmvps.com/jon.skeet
C# in Depth:http://csharpindepth.com

I've tested on two PCs, both the same.
Can some one post a tested working code of query the XML by using LINQ
with compact framework?

**Jon Skeet [C# MVP]** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

Wan <luowan@gmail.c omwrote:

I've tested on two PCs, both the same.
Can some one post a tested working code of query the XML by using LINQ
with compact framework?

Well hang on - you've posted an error which you look in the debugger.
You've said the program is still running. What's it doing that you
don't expect it to?

Could you post a short but complete program which demonstrates the
problem?

See http://www.pobox.com/~skeet/csharp/complete.html for details of
what I mean by that.

--
Jon Skeet - <skeet@pobox.co m>
Web site: http://www.pobox.com/~skeet
Blog: http://www.msmvps.com/jon.skeet
C# in Depth: http://csharpindepth.com

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On Apr 30, 10:14 pm, Jon Skeet [C# MVP] <sk...@pobox.co mwrote:

Wan <luo...@gmail.c omwrote:

I've tested on two PCs, both the same.
Can some one post a tested working code of query the XML by using LINQ
with compact framework?

>
Well hang on - you've posted an error which you look in the debugger.
You've said the program is still running. What's it doing that you
don't expect it to?
>
Could you post a short but complete program which demonstrates the
problem?
>
Seehttp://www.pobox.com/~skeet/csharp/complete.htmlfo r details of
what I mean by that.
>
--
Jon Skeet - <sk...@pobox.co m>
Web site:http://www.pobox.com/~skeet
Blog:http://www.msmvps.com/jon.skeet
C# in Depth:http://csharpindepth.com

Here is the full sample code. with the XML sample.

Code Snippetusing System;

using System.Linq;

using System.Collecti ons.Generic;

using System.Componen tModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows. Forms;

using System.Xml.Linq ;

using System.Xml;

namespace xmlCFtest

{

public partial class Form1 : Form

{

public Form1()

{

InitializeCompo nent();

updateMsg("1472 2", 5);

}

private void updateMsg(strin g MsgID, int newStatus)

{

try

{

XmlReaderSettin gs settings = new XmlReaderSettin gs();

settings.Confor manceLevel = ConformanceLeve l.Fragment;

settings.Ignore Whitespace = true;

settings.Ignore Comments = true;

XmlReader reader = XmlReader.Creat e(@"Program Files\messagecl ient\XML
\Inbox.xml", settings);

XElement root = XElement.Load(r eader);

IEnumerable<XEl ementmsgs = from el in root.Descendant s("Message")

where el.Element("Mes sageID").Value == MsgID

select el;

foreach (XElement el in msgs)

{

el.Element("Mes sageStaus").Set Value(newStatus .ToString());

}

root.Save(@"Pro gram Files\messagecl ient\XML\Inbox. xml");

}

catch (Exception e) { }

}

}

}

XML Sample:

Code Snippet<?xml version="1.0"?>
<ArrayOfMessa ge xmlns:xsi="http ://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http ://www.w3.org/2001/XMLSchema">
<Message>
<IMEI xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">35 340401169569600 </IMEI>
<MessageText xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">hi </MessageText>
<MessageID xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">14 722</MessageID>
<UserID xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">12 984</UserID>
<SenderName xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">Ha rdCode Test </SenderName>
<TimeStamp xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">20 08-04-29T16:26:36.097 </TimeStamp>
<MessageStaus xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">3</MessageStaus>
</Message>

</ArrayOfMessage>

Hi Jon
When I said the program was running, I mean the code was compiled.
However, the code does not do the job. The project I created was
based on Windows Mobile 6 SDK and Compact Framework 3.5.

Regards,
Wan

**Jon Skeet [C# MVP]** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 10:56 am, Wan <luo...@gmail.c omwrote:

Here is the full sample code. with the XML sample.

Well, it's not exactly a full sample - it doesn't contain a Main
method, for instance. It's not even a complete class - where's the
implementation of InitializeCompo nent?
Hint: console apps are generally a lot shorter.

See http://pobox.com/~skeet/csharp/incomplete.html

When I said the program was running, I mean the code was compiled.
However, the code does not do the job. The project I created was
based on Windows Mobile 6 SDK and Compact Framework 3.5.

When you say "the code does not do the job" what exactly do you mean?
What does it do, and what do you want it to do?

Jon

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 11:44 am, "Jon Skeet [C# MVP]" <sk...@pobox.co mwrote:

On May 1, 10:56 am, Wan <luo...@gmail.c omwrote:
>

Here is the full sample code. with the XML sample.

>
Well, it's not exactly a full sample - it doesn't contain a Main
method, for instance. It's not even a complete class - where's the
implementation of InitializeCompo nent?
Hint: console apps are generally a lot shorter.
>
Seehttp://pobox.com/~skeet/csharp/incomplete.html
>

When I said the program was running, I mean the code was compiled.
However, the code does not do the job. The project I created was
based on Windows Mobile 6 SDK and Compact Framework 3.5.

>
When you say "the code does not do the job" what exactly do you mean?
What does it do, and what do you want it to do?
>
Jon

Hi Jon

I think it is complete, Please create a windows application project
with smart device. Put the code under Form.cs. I don't think you
need to implement a 'Main'.

Regards,
Wan

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 11:44 am, "Jon Skeet [C# MVP]" <sk...@pobox.co mwrote:

On May 1, 10:56 am, Wan <luo...@gmail.c omwrote:
>

Here is the full sample code. with the XML sample.

>
Well, it's not exactly a full sample - it doesn't contain a Main
method, for instance. It's not even a complete class - where's the
implementation of InitializeCompo nent?
Hint: console apps are generally a lot shorter.
>
Seehttp://pobox.com/~skeet/csharp/incomplete.html
>

When I said the program was running, I mean the code was compiled.
However, the code does not do the job. The project I created was
based on Windows Mobile 6 SDK and Compact Framework 3.5.

>
When you say "the code does not do the job" what exactly do you mean?
What does it do, and what do you want it to do?
>
Jon

'InitializeComp onent' method is generated when the project is
created. Since VS 2005, it is seperated from the form class.

Regards,
Wan

**Jon Skeet [C# MVP]** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 12:43 pm, Wan <luo...@gmail.c omwrote:

I think it is complete,

No, it's definitely not.

Please create a windows application project
with smart device. Put the code under Form.cs. I don't think you
need to implement a 'Main'.

Only because Visual Studio creates another file for you that *does*
contain Main. Likewise the Form1.Designer. cs file contains
InitializeCompo nent. Without that, it's not complete.

In short, I can't cut and paste the code into a text editor *on its
own* and compile from the command line, which is what I tend to do
with newsgroup posts. Again, please read

Pobox is now part of Fastmail

http://pobox.com/~skeet/csharp/incomplete.html

Pobox has been discontinued as a separate service, and all existing customers moved to the Fastmail platform.

You also *still* haven't said how it behaves differently to how you
expect it to.

Jon

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 1:07 pm, "Jon Skeet [C# MVP]" <sk...@pobox.co mwrote:

On May 1, 12:43 pm, Wan <luo...@gmail.c omwrote:
>

I think it is complete,

>
No, it's definitely not.
>

Please create a windows application project
with smart device. Put the code under Form.cs. I don't think you
need to implement a 'Main'.

>
Only because Visual Studio creates another file for you that *does*
contain Main. Likewise the Form1.Designer. cs file contains
InitializeCompo nent. Without that, it's not complete.
>
In short, I can't cut and paste the code into a text editor *on its
own* and compile from the command line, which is what I tend to do
with newsgroup posts. Again, please readhttp://pobox.com/~skeet/csharp/incomplete.html
>
You also *still* haven't said how it behaves differently to how you
expect it to.
>
Jon

Ok, I am not sure if you complie it from command line will help to see
the problem. As the program was complied with no errors.

I expect this piece of code can go to the XML I pasted, and find the
element as well as changing the value. However, it didn't changed
value. even though it found the XML file, loaded XML, ran the LINQ
statement. Finally when I check the value of "IEnumerable<XE lement>
msgs" by watching this variable. It will give me such error message:

msgs.System.Col lections.Generi c.IEnumerator<T Source>.Current
'System.Collect ions.Generic.IE numerable<Syste m.Xml.Linq.XEle ment>'
does not contain a definition for 'System' and no extension method
'System' accepting a first argument of type
'System.Collect ions.Generic.IE numerable<Syste m.Xml.Linq.XEle ment>'
could be found (are you missing a using directive or an assembly
reference?)

I assume, it might be problem of 'System.Collect ions.Generic' for
compact framework, does not support the XElement type.

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 1:07 pm, "Jon Skeet [C# MVP]" <sk...@pobox.co mwrote:

On May 1, 12:43 pm, Wan <luo...@gmail.c omwrote:
>

I think it is complete,

>
No, it's definitely not.
>

Please create a windows application project
with smart device. Put the code under Form.cs. I don't think you
need to implement a 'Main'.

>
Only because Visual Studio creates another file for you that *does*
contain Main. Likewise the Form1.Designer. cs file contains
InitializeCompo nent. Without that, it's not complete.
>
In short, I can't cut and paste the code into a text editor *on its
own* and compile from the command line, which is what I tend to do
with newsgroup posts. Again, please readhttp://pobox.com/~skeet/csharp/incomplete.html
>
You also *still* haven't said how it behaves differently to how you
expect it to.
>
Jon

The Program Has three files

1. Program.cs
using System;
using System.Linq;
using System.Collecti ons.Generic;
using System.Windows. Forms;

namespace xmlCFtest
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[MTAThread]
static void Main()
{
Application.Run (new Form1());
}
}
}

2. Form1.cs
using System;
using System.Linq;
using System.Collecti ons.Generic;
using System.Componen tModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows. Forms;
using System.Xml.Linq ;
using System.Xml;

namespace xmlCFtest
{
public partial class Form1 : Form
{
public Form1()
{
InitializeCompo nent();
updateMsg("1472 2", 5);
}

private void updateMsg(strin g MsgID, int newStatus)
{
try
{
lock ("Hello")
{
XmlReaderSettin gs settings = new
XmlReaderSettin gs();
settings.Confor manceLevel =
ConformanceLeve l.Fragment;
settings.Ignore Whitespace = true;
settings.Ignore Comments = true;
XmlReader reader = XmlReader.Creat e(@"Program Files
\messageclient\ XML\Inbox.xml", settings);

XElement root = XElement.Load(r eader);
IEnumerable<XEl ementmsgs = from el in
root.Descendant s("Message")
where
el.Element("Mes sageID").Value == MsgID
select el;

foreach (XElement el in msgs)
{

el.Element("Mes sageStaus").Set Value(newStatus .ToString());
}

root.Save(@"Pro gram Files\messagecl ient\XML
\Inbox.xml");
}
}
catch (Exception e) { }

}
}
}

3. Form1.Designer. cs
namespace xmlCFtest
{
partial class Form1
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.Componen tModel.IContain er components = null;
private System.Windows. Forms.MainMenu mainMenu1;

/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing ">true if managed resources should
be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Disp ose();
}
base.Dispose(di sposing);
}

#region Windows Form Designer generated code

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeCompo nent()
{
this.mainMenu1 = new System.Windows. Forms.MainMenu( );
this.Menu = this.mainMenu1;
this.components = new System.Componen tModel.Containe r();
this.AutoScaleM ode =
System.Windows. Forms.AutoScale Mode.Dpi;
this.Text = "Form1";
this.AutoScroll = true;
}

#endregion
}
}

Regards,
Wan

**Jon Skeet [C# MVP]** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 1:27 pm, Wan <luo...@gmail.c omwrote:

Ok, I am not sure if you complie it from command line will help to see
the problem.

It would if you would tell us how the program behaved differently to
how you expected - without referring to the debugger.

As the program was complied with no errors.

Yes, many short but complete programs do.

I expect this piece of code can go to the XML I pasted, and find the
element as well as changing the value. However, it didn't changed
value. even though it found the XML file, loaded XML, ran the LINQ
statement. Finally when I check the value of "IEnumerable<XE lement>
msgs" by watching this variable. It will give me such error message:

Yes, so you've said. That's in the debugger. Now, can you show a
program which produces output X when you expect output Y, without
having to break and look at the debugger? If it's *only* an issue with
the debugger, I'm unlikely to be able to help. If the program isn't
working as expected however, then please specify in what way that is
the case.

Here's an example of what I mean:

<sample post>
Problem: Addition with large numbers appears not to work.

I'm having trouble with addition when it comes to large integers

Program:
using System;

class Test
{
static void Main()
{
int i = 2147483647;
Console.WriteLi ne("i={0}", i);
Console.WriteLi ne("i+1={0}", i+1);
}
}

Expected output:
i=2147483647
i+1=2147483648

Actual output:
i=2147483647
i+1=-2147483648

Note that the result is negative. Why?
</sample post>

At this point:
a) I can easily compile and run the code
b) I can understand the problem
c I can verify that I see the problem too
d) I can easily change the code to try to fix it

Now obviously that's a trivial example - but it's a good model. While
you can only express what's wrong in terms of watching a variable in
the debugger, I'm inclined to put the issue down to a debugger
problem.

Jon

**Wan** · Jun 27 '08, 07:48 PM

Re: LINQ and XML for compact framework

On May 1, 2:09 pm, "Jon Skeet [C# MVP]" <sk...@pobox.co mwrote:

On May 1, 1:27 pm, Wan <luo...@gmail.c omwrote:
>

Ok, I am not sure if you complie it from command line will help to see
the problem.

>
It would if you would tell us how the program behaved differently to
how you expected - without referring to the debugger.
>

As the program was complied with no errors.

>
Yes, many short but complete programs do.
>

I expect this piece of code can go to the XML I pasted, and find the
element as well as changing the value. However, it didn't changed
value. even though it found the XML file, loaded XML, ran the LINQ
statement. Finally when I check the value of "IEnumerable<XE lement>
msgs" by watching this variable. It will give me such error message:

>
Yes, so you've said. That's in the debugger. Now, can you show a
program which produces output X when you expect output Y, without
having to break and look at the debugger? If it's *only* an issue with
the debugger, I'm unlikely to be able to help. If the program isn't
working as expected however, then please specify in what way that is
the case.
>
Here's an example of what I mean:
>
<sample post>
Problem: Addition with large numbers appears not to work.
>
I'm having trouble with addition when it comes to large integers
>
Program:
using System;
>
class Test
{
static void Main()
{
int i = 2147483647;
Console.WriteLi ne("i={0}", i);
Console.WriteLi ne("i+1={0}", i+1);
}
>
}
>
Expected output:
i=2147483647
i+1=2147483648
>
Actual output:
i=2147483647
i+1=-2147483648
>
Note that the result is negative. Why?
</sample post>
>
At this point:
a) I can easily compile and run the code
b) I can understand the problem
c I can verify that I see the problem too
d) I can easily change the code to try to fix it
>
Now obviously that's a trivial example - but it's a good model. While
you can only express what's wrong in terms of watching a variable in
the debugger, I'm inclined to put the issue down to a debugger
problem.
>
Jon

The original XML file:

<?xml version="1.0"?>
<ArrayOfMessa ge xmlns:xsi="http ://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http ://www.w3.org/2001/XMLSchema">
<Message>
<IMEI xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">35 340401169569600 </IMEI>
<MessageText xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">hi </MessageText>
<MessageID xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">14 722</MessageID>
<UserID xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">12 984</UserID>
<SenderName xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">Ha rdCode Test </SenderName>
<TimeStamp xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">20 08-04-29T16:26:36.097 </TimeStamp>
<MessageStaus xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">3</MessageStaus>
</Message>
</ArrayOfMessage>

After run the program I wrote, I expect the XML to become:
<?xml version="1.0"?>
<ArrayOfMessa ge xmlns:xsi="http ://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http ://www.w3.org/2001/XMLSchema">
<Message>
<IMEI xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">35 340401169569600 </IMEI>
<MessageText xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">hi </MessageText>
<MessageID xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">14 722</MessageID>
<UserID xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">12 984</UserID>
<SenderName xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">Ha rdCode Test </SenderName>
<TimeStamp xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">20 08-04-29T16:26:36.097 </TimeStamp>
<MessageStaus xmlns="http://FleetMatics.com/WCFMessageServi ce/
Message.xsd">5</MessageStaus>
</Message>
</ArrayOfMessage>

The last element <MessageStaus ></MessageStaussho uld change its
value.

Actual Output has nothing changed. However, if I created a normal
framework console application project. And copy, paste this code, it
will do the job. That's why I want to ask how to use LINQ to modify
XML in compact framework.

Wan