Question

I am trying to copy an object onto the windows clipboard and off again. My code is like this:

Copy on to clipboard:

Clipboard.Clear();
DataObject newObject = new DataObject(prompts);
newObject.SetData(myString);
Clipboard.SetDataObject(newObject);

Where prompts is a List<Data.Sources.PromptResult> collection.

Copy off clipboard:

IDataObject dataObject = System.Windows.Forms.Clipboard.GetDataObject();
if (dataObject.GetDataPresent(typeof(List<Data.Sources.PromptResult>)))
{
  Type type = typeof(List<Data.Sources.PromptResult>);
  Object obj = dataObject.GetData(type);
  return (List<Data.Sources.PromptResult>)dataObject.GetData(type);
}

The GetFormats() shows the format as being in the list and the GetDataPresent(List<Data.Sources.PromptResult>) returns true but if I try to get the object out of the Clipboard class with GetData(List<Data.Sources.PromptResult>) I get a return of null.

Does anyone have any idea what might be wrong?

Answer 1

OK I tried to add list of my user type to clipboard and get it back…
Here is what I tried:

My User Class:

public class User
{
   public int Age { get; set; }
   public string Name { get; set; }
}

Rest of Code:

// Create User list and add some users
List<User> users = new List<User>();
users.Add(new User { age = 15, name = "Peter" });
users.Add(new User { age = 14, name = "John" });

// Lets say its my data format
string format = "MyUserList";
Clipboard.Clear();

// Set data to clipboard
Clipboard.SetData(format, users);

// Get data from clipboard
List<User> result = null;
if (Clipboard.ContainsData(format))
    result = (List<User>)Clipboard.GetData(format);

…and result was null 🙂
…until I marked User class as Serializable

[Serializable]
public class User
{ 
    //...   
}

After that my code worked.
Ok its not the answer but maybe it helps you some how.