Serialize multiple objects into XML

Question

I try the following code to serialize my objects into xml file, but when run this code the last item in the list values serialize by the count for the list.

I want to serialize every item in the list? what is the wrong in my code

Can anyone help me ?

//list of class values               
List<values> valus = new List<values>();
values value = new values();

foreach (Control control in Controls)
{
    value.ctrlname = control.Name.ToString();
    value.ctrllocation = control.Location.ToString();
    value.ctrltext = control.Text.ToString();
    value.ctrltype = control.GetType().ToString();
    value.ctrlstatus = control.Enabled.ToString();

    valus.Add(value);    
}

System.Xml.Serialization.XmlSerializer writer =
       new System.Xml.Serialization.XmlSerializer(typeof(values));

var path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + "//Serialization.xml";
System.IO.FileStream file = System.IO.File.Create(path);

foreach (values item in valus)
{
    writer.Serialize(file, item);
}

file.Close();

You are repeatedly overwriting the same file so your file ends up containing the last item, serialise the list, not each item one at once. — Ben Robinson, Sep 17 '15 at 11:21

score 0 · Answer 1 · edited May 23 '17 at 12:31

0

write.Serialize is probably overwriting whats in the file each time rather then appending. You could try serializing the values to a string like in this question: Serialize an object to string. And then manually appending to the file with the string values.

Alternatively you could serialize the whole list rather then each value at a time.

edited May 23 '17 at 12:31

Community

1
1

answered Sep 17 '15 at 11:22

Lex Webb

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jcwilbur · Answer 2 · 2015-09-17T11:34:42.453

Your first foreach loop that fills the list is repeatedly overwriting the same value object and adding new references to same object repeatedly to the List. You're not actually adding a new item to your list when you call valus.Add(value);.

Try moving the line values value = new values(); to the top of the foreach loop or, if you're particularly worried about efficiency of declaring an object multiple times, keep the line values value; outside the loop and add the line value = new values(); inside the foreach loop.

Yael · Accepted Answer · 2015-09-17T11:47:26.003

First lets validate that your classes are serialzble, like so:

[Serializable()]
public class rootValues
{
    public rootValues()
    {
        valuesArray = new List<values>(); 
    }

    [XmlElement("item", typeof(values))]
    public List<values> valuesList { get; set; }
} 

[Serializable()]
public class values
{
    [System.Xml.Serialization.XmlAttribute("ctrlname")]
    public string ctrlname { get; set; }

    //....
}

Second, your using the same name for the list and object

//list of class values               
rootValues valusList = new rootValues();

foreach (Control control in Controls)
{
    values value = new values(); // Create new element, in your code it was the same

    value.ctrlname = control.Name.ToString();
    value.ctrllocation = control.Location.ToString();
    value.ctrltext = control.Text.ToString();
    value.ctrltype = control.GetType().ToString();
    value.ctrlstatus = control.Enabled.ToString();

    valuesList.valuesList.Add(value);    
}

System.Xml.Serialization.XmlSerializer writer = new System.Xml.Serialization.XmlSerializer(typeof(rootValues));
var path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) + "//Serialization.xml";
System.IO.FileStream file = System.IO.File.Create(path);
writer.Serialize(file, valusList);
file.Close();

FYI, if you want to add a list of class values you can do it like so:

//...
List<values> SomeListOfvalues =  new List<values>(); 

// Init list
SomeListOfvalues.add(new values()); // Adding first element
SomeListOfvalues.add(new values()); // Adding second element

// Adding the whole list to our class
valuesList.valuesList.addRange(SomeListOfvalues );

what is valuesList in valuesList.Add(value); are you mean valusList ? after replaced it by valusList give me an error not contain Add method — Ahmed, Sep 17 '15 at 11:33
about valuesList if i want to add list of values named by valuesList ? — Ahmed, Sep 17 '15 at 11:37
just last comment how can use `valuesList.valuesList.AddRange(SomeotherValueList)` How can use that — Ahmed, Sep 17 '15 at 11:42
Note that one important change you made in this answer from the OP's code is initializing the `value` object within the foreach loop. Without that, the code creates multiple references to the same `value` object. I think it's important to call this out. — jcwilbur, Sep 17 '15 at 11:42

Serialize multiple objects into XML

3 Answers3