type or namespace name 'Serializable' does not exist in the namespace 'System' (are you missing an assembly reference?

Question

I am VS 2012 silverlight-5 beginner. I tried to serialize and de-serialize from a xml file. I have following error while doing this :

The type or namespace name 'Serializable' does not exist in the namespace 'System' (are you missing an assembly reference?) 
The type or namespace name 'SerializableAttribute' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'DatamemberAttribute' could not be found (are you missing a using directive or an assembly reference?)
The type or namespace name 'Datamember' could not be found (are you missing a using directive or an assembly reference?)

My code for serialization is :

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Runtime.Serialization.Json;
using System.Runtime;
using System.Xml.Serialization;
using System.Runtime.Serialization;
using System.IO;

namespace Model.XML
{   
        public static class Serialization<T> where T : class
        {

            public static T DeserializeFromXmlFile(string fileName)
            {
                if (!File.Exists(fileName))
                {
                    return null;
                }

                DataContractSerializer deserializer = new DataContractSerializer(typeof(T));

                using (Stream stream = File.OpenRead(fileName))
                {
                    return (T)deserializer.ReadObject(stream);
                }
            }
        }

}

But i am interested in having each class seperately (not all the 3 classes (parameter,component and attribute) obtained in one class).

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Runtime.Serialization.Json;
using System.Runtime;
using System.Xml.Serialization;
using System.Runtime.Serialization;
using System.IO;
using System.Xml.Serialization.XmlTypeAttribute;
using System.Serializable;          //It gives red line under Serializable



namespace Model.XML
{
    [Serializable] //It gives red line
    public class attribute
    {
        [Datamember] //It gives red line
        public string name { get; set; }

        [Datamember] //It gives red line
        public string label { get; set; }

        [Datamember] //It gives red line
        public string unit { get; set; }

        [Datamember] //It gives red line
        public component thisComponent { get; set; }
    }
}

i tried to reference using System.Serializable; but it is not available in the dll list i have in my VS2012. What is the cause of problem and how to get a rid of it ? Thanks in advance.

EDIT AFTER Comments:

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Runtime.Serialization.Json;
using System.Runtime;
using System.Xml.Serialization;
using System.Runtime.Serialization;
using System.IO;
using System.Collections.Generic;


namespace Model.XML
{
    [DataContract]
    public class attribute
    {
        [DataMember]
        public string type { get; set; }

        [DataMember]
        public string displayed { get; set; }

        [DataMember]
        public string add_remove { get; set; }

        [DataMember]
        public string ccypair { get; set; }

        [DataMember]
        public List<int> item { get; set; }

        public static void Main()
        {
            attribute Obj1 = Serialization<attribute>.DeserializeFromXmlFile("C:\\Users\\SHEK\\Desktop\\VannakNew\\DEV_CENTER\\Model\\XML\\XmlParameter.xml");
         // Obj1.type = "shekhar";

        }

    }
}

And serialization.cs is :

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Runtime.Serialization.Json;
using System.Runtime;
using System.Xml.Serialization;
using System.Runtime.Serialization;
using System.IO;

namespace Model.XML
{   
        public static class Serialization<T> where T : class
        {

            public static T DeserializeFromXmlFile(string fileName)
            {
                if (!File.Exists(fileName))
                {
                    MessageBox.Show("File Path is wrong");
                    return null;
                }

                DataContractSerializer deserializer = new DataContractSerializer(typeof(T));

                using (Stream stream = File.OpenRead(fileName))
                {
                    return (T)deserializer.ReadObject(stream);
                }
            }
        }

}

Xml file is XmlParameter.xml

<?xml version="1.0" encoding="utf-8" ?>
<parameter>
  <name>bands_amounts</name>
  <label>Bands Amounts</label>
  <unit></unit>
  <component>
    <type>List</type>
    <attributes>
      <type>Integer</type>
      <displayed>4</displayed>
      <add_remove>yes</add_remove>
      <item>1 000 000</item>
      <item>5 000 000</item>
      <item>10 000 000</item>
      <item>20 000 000</item>
    </attributes>
    <attributes>
      <ccypair>XAUUSD</ccypair>
      <item>100</item>
      <item>500</item>
      <item>1000</item>
    </attributes>
  </component >
</parameter>

**It is working without error but i wonder why it always null object(on debugging) even the path of XmlParameter.xml file is correct. Is it due to using "[DataContract]" instead of [Serialized] ? because it si silverlight application. Actually i have todisplay the elements inside the nodes like,i have to display "XAUUSD" in my attribute.cs class which present in node <ccypair>XAUUSD</ccypair> **

Solution 1

There is no System.Serializable namespace; the SerializableAttribute class is in the System namespace. You should just write using System;.

I think you're confusing C# using statements with Java import statement. In Java, you import specific classes (or all classes from a package with *). In C#, the using statement imports all types in the specified namespace.

Currently, specifying a class name after using is an error, but in C# 6 it will be possible, and will import all static members from the class.

---

Other issue: you wrote Datamember instead of DataMember; C# is case sensitive. And anyway, DataMember has no effect on a class that doesn't have the DataContract attribute.

Also make sure you have referenced the System.Runtime.Serialization assembly.

Solution 2

I got the same problem and by adding this resolved the problem

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

Comments

[Thomas Levesque]

@user234839, remove the using System.Serializable; statement

[Sss]

I dont it but still those eror persists

[Thomas Levesque]

@user234839, which platform are you targeting? Is it a Windows Store or Windows Phone app?

[Sss]

Hav you understood the question ? I have an xml file and i create seralizer using c# (i have written the code for that) but i want to seperate each class(instead all the 3 classes in one class) and "attribute" class is the first class from which i started and it gives those errors.

[Sss]

DatamEMBER ISSUE IS SOLVED nOW JUST SERALIZABLE IS left.

[Thomas Levesque]

@user234839, SerializableAttribute is not available in Silverlight. Just use DataContract instead

[Sss]

It solved the error currently but the problem is when i try to do Serialization<YourCustomObject>.DeserializeFromXmlFile(MyFil‌​eNameOrPath); in "attribute" class. Then will it work (in fact this line gives error)? what should be the alternative. And Serializable is not supported in silverlight. What should i use now ?

[Sss]

I write this line : Serialization<YourCustomObject>.DeserializeFromXmlFile("XmlP‌​arameter.xml"); And the errors are as below

[Sss]

First :Error 1 Invalid token '(' in class, struct, or interface member declaration C:\Users\SHEK\Desktop\VannakNew\DEV_CENTER\Model‌​\XML\attribute.cs Second : Error 2 The type or namespace name 'YourCustomObject' could not be found (are you missing a using directive or an assembly reference?) C:\Users\SHEK\Desktop\VannakNew\DEV_CENTER\Model‌​\XML\attribute.cs Third :Error 3 'Model.XML.Serialization<T>.DeserializeFromXmlFile(‌​string)' is a 'method' but is used like a 'type' C:\Users\SHEK\Desktop\VannakNew\DEV_CENTER\Model\XML\‌​attribute.cs

[Thomas Levesque]

@user234839, where do you write this code? Please edit your question to show the new code for the attribute class. What what is YourCustomObject? Does it even exist? The compiler seems to think it doesn't...

[Sss]

Thanks for trying to help me.I have just edited the question. I solved these errors (It was because i was not writting that inside static void main() function). But the problem is it always returns null object (Is there any problem remated to xml file path ? Because it always popups the MessageBox which i have in Serialization.cs class)

[Sss]

You can have a look i have included xml file and other 2 files.

[Thomas Levesque]

@user234839, well, the only possible cause is that the file you specified doesn't exist... But anyway, if the attribute element is not the root of the XML, trying to deserialize it to class attribute won't work... you must deserialize to parameter instead

[Sss]

But the file exist there. Even all these classes files and xml files are in same folder

[Thomas Levesque]

@user234839, well, I don't think there's a bug in File.Exists... it would have been found a loooong time ago. So, the bug is somewhere else. Are you really 100% sure the path is correct?

[Sss]

This path i have got fromhe properites click of xml file which i copied and pasted: C:\\Users\\SHEK\\Desktop\\VannakNew\\DEV_CENTER\\Model\\XML\‌​\XmlParameter.xml"