fieldInfo.SetValue throwing ArgumentException "Object type cannot be converted to target type"

Question

This is driving me nuts. Perhaps I'm missing something obvious?

The fieldInfo.FieldType is correct (DateTime), and the value I'm applying is also a DateTime.

for(int i=0; i<objectArray.Length; i++)
{
    FieldInfo destinationField = GetFieldInfo(i);
    object destinationValue = objectArray[i];

    destinationField.SetValue(this, destinationValue);
}

Edit: even if I set destinationValue to a literal DateTime (DateTime.Now), I still get the exception!

Answer 1

I am assuming that you want to set a property on your object and not a field (this might be your problem). If so then the following code might help?

public class Order
{
    public DateTime OrderDateField;
    public DateTime OrderDate { get; set; }
}

object[] orders = new[] { new Order(), new Order(), new Order() };
for (int i = 0; i < orders.Length; i++)
{
    FieldInfo fieldInfo = orders[i].GetType().GetField("OrderDateField");
    fieldInfo.SetValue(orders[i], DateTime.Now);

    PropertyInfo propertyInfo = orders[i].GetType().GetProperty("OrderDate");
    propertyInfo.SetValue(orders[i], DateTime.Now, null);
}

Is that the result you were trying to achieve?

Update: The above code updates both the property and field on the Order object.

Answer 2

Change

destinationField.SetValue(this, destinationValue);

To

destinationField.SetValue(objectArray[i], destinationValue);

There was a comment asking about the 'this' reference, but I lack the rep to reply there.

Answer 3

OK, I've figured it out.

If you ever see this Exception, there's a good chance the the FieldInfos you are using do not belong to the same object as your target. cough

Sorry for being a clot, thanks to all who helped out.