Appendix A. Enumeration Extension Methods
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LINQ Reporting Engine enables you to perform common manipulations on a sequential data through the engine’s built-in extension methods for IEnumerable. These extension methods mimic some extension methods of IEnumerable<T> providing the same signatures and behavior features. Thus you can group, sort and perform other sequential data manipulations in template expressions in a familiar way.
The following table describes these built-in extension methods. The following notation conventions are used within the table:
Selectorstands for a lambda function returning a value and taking an enumeration item as its single argument. See “Using Lambda Functions” for more information.ComparableSelectorstands forSelectorreturning IComparable.EnumerationSelectorstands forSelectorreturningIEnumerable.Predicatestands forSelectorreturning aBooleanvalue.
Examples in the following table are given using persons and otherPersons, enumerations of instances of the Person class that is defined as follows.
public class Person
{
public String Name { get { ... } }
public int Age { get { ... } }
public IEnumerable<Person> Children { get { ... } }
...
}
| Extension Method | Examples and Notes |
|---|---|
All(Predicate) |
|
Any() |
|
Any(Predicate) |
|
Average(Selector) |
|
Concat(IEnumerable) |
|
Contains(Object) |
|
Count() |
|
Count(Predicate) |
|
Distinct() |
|
ElementAt(int) |
|
ElementAtOrDefault(int) |
|
First() |
|
First(Predicate) |
|
FirstOrDefault() |
|
FirstOrDefault(Predicate) |
|
GroupBy(Selector) |
Key property. You can treat a group itself as an enumeration of items that the group contains. |
Last() |
|
Last(Predicate) |
|
LastOrDefault() |
|
LastOrDefault(Predicate) |
|
Max(ComparableSelector) |
|
Min(ComparableSelector) |
|
OrderBy(ComparableSelector) |
- ThenBy(ComparableSelector) - ThenByDescending(ComparableSelector) |
OrderByDescending(ComparableSelector) |
|
Select(Selector) |
|
SelectMany(EnumerationSelector) |
|
Single() |
|
Single(Predicate) |
|
SingleOrDefault() |
|
SingleOrDefault(Predicate) |
|
Skip(int) |
|
SkipWhile(Predicate) |
|
Sum(Selector) |
|
Take(int) |
|
TakeWhile(Predicate) |
|
Union(IEnumerable) |
|
Where(Predicate) |
|