Gowtham Gopalsamy reported Nov 08 at 11:43 AM

I am trying to sort the dynamic collection and it is working fine when the column doesn't have null value. If the column having null value, then sorting the dynamic collection throws ArgumentException. Here is the sample dynamiccollectionsimplesample.zip.

var dt = GetDataTable();
var dynamicCollection = new ObservableCollection<ExpandoObject>();
foreach (System.Data.DataRow row in dt.Rows)
{
    ExpandoObject dyn = new ExpandoObject();
    dynamicCollection.Add(dyn);
    foreach (System.Data.DataColumn column in dt.Columns)
    {
        var dic = (IDictionary<string, object>)dyn;
        dic[column.ColumnName] = row[column];
    }
}
var expressionFunc = GetExpressionFunc("OrderID");
var source = dynamicCollection.AsQueryable();
var sourceType = source.ElementType;
var paramExpression = Expression.Parameter(sourceType, sourceType.Name);
var cExp = Expression.Constant("OrderID");
var iExp = Expression.Invoke(expressionFunc, new Expression[] { cExp, paramExpression });
var lambda = Expression.Lambda(iExp, paramExpression);
var orderedSource = source.Provider.CreateQuery(
    Expression.Call(
        typeof(Queryable),
        "OrderBy",
        new Type[] { source.ElementType, lambda.Body.Type },
        source.Expression,
        lambda
        )
    );
var enumerable = orderedSource as IEnumerable;
if (enumerable.GetEnumerator().MoveNext())
{
}

Could anyone please update me, why sorting with null value in dynamic collection throws exception?

For null values in the dynamic collection, null values are shown as Curly phrase{} like this shown in below image,

Why dynamic collection with null value is takes as {} ?

And this issue occurs only when we sort the collection with this '{}' only. If we format the value through string format, value is returned as 'null' and it is working fine.

Could anyone please update me, why exception occurs only when sorting the dynamic collection with '{}' ?

Thanks,

Gowtham