XmlSerializer: The string '' is not a valid AllXsd value

Question

I\'m getting this message,\"The string \'7/22/2006 12:00:00 AM\' is not a valid AllXsd value.\", when deserializing an XML, the element contains a date, this is the property

Answer 1

I realize that this is an old question, but I had this issue today and I found a workaround using properties and casting.

private string _date; // Private variable to store XML string

// Property that exposes date. Specifying the type forces
// the serializer to return the value as a string.
[XmlElement("date", Type = typeof(string))]
public object Date {
    // Return a DateTime object
    get
    {
        return
            !string.IsNullOrEmpty(_date) ? 
            (DateTime?) Convert.ToDateTime(_date) : 
            null;
    }
    set { _date = (string)value; } 
}

Now, whenever you need to refer to the date, you simply call:

var foo = (DateTime?)Bar.Date

It's been working fine for me since. If you don't mind adding the extra cast in your code, you can do it this way as well!

Edit: Due to Dirk's comment, I decided to revisit my implementation in a seperate branch. Rather than using an object class, which is prone to runtime compiler errors, I return the value as a string.

[XmlElement("date")] 
public string Date;

Which makes the declaration much simpler. But when attempting to read from the variable you now need to provide null checks.

var foo = string.IsNullOrEmpty(Date) ? Convert.ToDateTime(Date) : (DateTime?) null

It works the exact same way as the previous implementation, except the casting and null checks occur at a different location. I want to be able to write my model and then forget about it, so I still prefer my implementation instead.

On another note, I added a correction to the cast before the edit: DateTime should be DateTime?.