Question

i have a class which has a string and a hash table.hash table contains set of key(string) values and bitmap file for each key attribute.
how do i serialize this into binary file?

    public void SerializeObject(List<Poem> poems)
    {

        using (Stream stream = File.Open("data.bin", FileMode.Create))
        {
            BinaryFormatter bin = new BinaryFormatter();
            bin.Serialize(stream, poems);
        }
    }

    public List<Poem> DeSerializeObject()
    {
        List<Poem> poems1;
        using (Stream stream = File.Open("data.bin", FileMode.Open))
        {
            BinaryFormatter bin = new BinaryFormatter();

            var lizards2 = (List<Poem>)bin.Deserialize(stream);
            poems1 = (List<Poem>)lizards2;
        }
        return poems1;
    }

//poem class

   [Serializable()]
public class Poem  
{
    string poemName;
    Hashtable poemContent; contains set of keys(strings) , values(bitmap)//

    public Poem() {

        poemContent = new Hashtable();

    }
    public string PoemName
    {
        get { return poemName; }
        set { poemName = value; }
    }

    public Hashtable PoemContent
    {
        get { return poemContent; }
        set { poemContent = value; }
    }}

but this always generates errors.

Answer 1

I can run your code without error. Calling code:

   SerializeObject(new List<Poem>
                                {
                                    new Poem
                                        {
                                            PoemContent = new Hashtable {{"Tag", new System.Drawing.Bitmap(1, 1)}},
                                            PoemName = "Name"
                                        }
                                });

 var poems2 = DeserializeObject();

What is the error you are seeing? Is it a compiler error or a runtime exception? I can run this code without problem on an example list of poems. By the way, I recommend using Dictionary<K,V> instead of HashTable.