Class QueryableExtensions
Holds extension methods for System.
Inheritance
Namespace: Telerik.Windows.Data
Assembly: Telerik.Windows.Data.dll
Syntax
public static class QueryableExtensions : ObjectMethods
Aggregate(IQueryable, IEnumerable<AggregateFunction>)
Calculates the results of given aggregates functions on a sequence of elements.
Declaration
public static AggregateResultCollection Aggregate(this IQueryable source, IEnumerable<AggregateFunction> aggregateFunctions)Parameters
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System. An System. |
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System. The aggregate functions. |
Returns
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Aggregate Collection of Aggregate |
Aggregate(IQueryable, AggregateFunction)
Calculates the results of a given aggregate function on a sequence of elements.
Declaration
public static AggregateResultCollection Aggregate(this IQueryable source, AggregateFunction aggregateFunction)Parameters
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System. An System. |
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Aggregate The aggregate function. |
Returns
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Aggregate Collection of Aggregate |
Count(IQueryable)
Returns the number of elements in a sequence.
Declaration
public static int Count(this IQueryable source)Parameters
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System. The System. |
Returns
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System. The number of elements in the input sequence. |
Exceptions
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System.
|
ElementAt(IQueryable, Int32)
Returns the element at a specified index in a sequence.
Declaration
public static object ElementAt(this IQueryable source, int index)Parameters
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System. An System. |
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System. The zero-based index of the element to retrieve. |
Returns
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System. The element at the specified position in |
Exceptions
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System.
|
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System.
|
Except(IQueryable, IQueryable)
Produces the set difference of two sequences by using the default equality comparer to compare values.
Declaration
public static IQueryable Except(this IQueryable source1, IQueryable source2)Parameters
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System.
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System.
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Returns
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System.
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First(IQueryable)
Returns the firsts item in a sequence.
Declaration
public static object First(this IQueryable source)Parameters
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System. The System. |
Returns
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System. First element. |
GroupBy(IQueryable, IEnumerable<IGroupDescriptor>)
Groups the elements of a sequence according to a specified groupDescriptors.
Declaration
public static IQueryable GroupBy(this IQueryable source, IEnumerable<IGroupDescriptor> groupDescriptors)Parameters
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System. An System. |
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System. The group descriptors used for grouping. |
Returns
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System. An System. |
GroupBy(IQueryable, LambdaExpression)
Groups the elements of a sequence according to a specified key selector function.
Declaration
public static IQueryable GroupBy(this IQueryable source, LambdaExpression keySelector)Parameters
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System. An System. |
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System. A function to extract the key for each element. |
Returns
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System. An System. |
OrderBy(IQueryable, LambdaExpression)
Sorts the elements of a sequence in ascending order according to a key.
Declaration
public static IQueryable OrderBy(this IQueryable source, LambdaExpression keySelector)Parameters
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System. A sequence of values to order. |
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System. A function to extract a key from an element. |
Returns
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System. An System. |
OrderBy(IQueryable, LambdaExpression, Nullable<ListSortDirection>)
Calls OrdersortDirection.
Declaration
public static IQueryable OrderBy(this IQueryable source, LambdaExpression keySelector, Nullable<ListSortDirection> sortDirection)Parameters
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System. The source. |
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System. The key selector. |
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System. The sort direction. |
Returns
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System. An System. |
OrderByDescending(IQueryable, LambdaExpression)
Sorts the elements of a sequence in descending order according to a key.
Declaration
public static IQueryable OrderByDescending(this IQueryable source, LambdaExpression keySelector)Parameters
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System. A sequence of values to order. |
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System. A function to extract a key from an element. |
Returns
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System. An System. |
Page(IQueryable, Int32, Int32)
Pages through the elements of a sequence until the specified
pageIndex using pageSize.
Declaration
public static IQueryable Page(this IQueryable source, int pageIndex, int pageSize)Parameters
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System. A sequence of values to page. |
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System. Index of the page. |
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System. Size of the page. |
Returns
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System. An System. |
Select(IQueryable, IEnumerable<ISelectDescriptor>)
Selects a sequence of objects based on a IEnumerable of SelectDescriptor.
Declaration
public static IQueryable Select(this IQueryable source, IEnumerable<ISelectDescriptor> selectDescriptors)Parameters
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System. The source. |
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System. The select descriptor enumerable. |
Returns
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System. An System. |
Select(IQueryable, LambdaExpression)
Projects each element of a sequence into a new form.
Declaration
public static IQueryable Select(this IQueryable source, LambdaExpression selector)Parameters
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System. A sequence of values to project. |
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System. A projection function to apply to each element. |
Returns
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System. An System. |
Select(IQueryable, SelectDescriptorCollection)
Selects a sequence of objects based on a Select
Declaration
public static IQueryable Select(this IQueryable source, SelectDescriptorCollection selectDescriptors)Parameters
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System. The source. |
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Select The select descriptor collection. |
Returns
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System. An System. |
Skip(IQueryable, Int32)
Bypasses a specified number of elements in a sequence and then returns the remaining elements.
Declaration
public static IQueryable Skip(this IQueryable source, int count)Parameters
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System. An System. |
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System. The number of elements to skip before returning the remaining elements. |
Returns
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System. An System. |
Exceptions
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System.
|
Sort(IQueryable, IEnumerable<ISortDescriptor>)
Sorts the elements of a sequence using the specified sort descriptors.
Declaration
public static IQueryable Sort(this IQueryable source, IEnumerable<ISortDescriptor> sortDescriptors)Parameters
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System. A sequence of values to sort. |
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System. The sort descriptors used for sorting. |
Returns
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System. An System. |
Sort(IQueryable, IEnumerable<SortDescriptor>)
Sorts the elements of a sequence using the specified sort descriptors.
Declaration
public static IQueryable Sort(this IQueryable source, IEnumerable<SortDescriptor> sortDescriptors)Parameters
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System. A sequence of values to sort. |
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System. The sort descriptors used for sorting. |
Returns
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System. An System. |
Sort(IQueryable, SortDescriptorCollection)
Sorts the elements of a sequence using the specified sort descriptors.
Declaration
public static IQueryable Sort(this IQueryable source, SortDescriptorCollection sortDescriptors)Parameters
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System. A sequence of values to sort. |
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Sort The sort descriptors used for sorting. |
Returns
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System. An System. |
Take(IQueryable, Int32)
Returns a specified number of contiguous elements from the start of a sequence.
Declaration
public static IQueryable Take(this IQueryable source, int count)Parameters
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System. The sequence to return elements from. |
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System. The number of elements to return. |
Returns
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System. An System. |
Exceptions
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System.
|
ToIList(IQueryable)
Creates a System.Collections.Generic.IList<> from an System.
Declaration
public static IList ToIList(this IQueryable source)Parameters
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System. The System. |
Returns
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System. A System.Collections.Generic.List<> that contains elements from the input sequence. |
Exceptions
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System.
|
ToIList<T>(IQueryable<T>)
Creates a System.Collections.Generic.IList<> from an System.
Declaration
public static IList<T> ToIList<T>(this IQueryable<T> source)Parameters
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System. The System. |
Returns
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System. A System.Collections.Generic.List<> that contains elements from the input sequence. |
Type Parameters
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T
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Exceptions
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System.
|
Union(IQueryable, IQueryable)
Produces the set union of two sequences by using the default equality comparer.
Declaration
public static IQueryable Union(this IQueryable source1, IQueryable source2)Parameters
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System.
|
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System.
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Returns
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System.
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Where(IQueryable, IEnumerable<IFilterDescriptor>)
Filters a sequence of values based on a collection of IFilter
Declaration
public static IQueryable Where(this IQueryable source, IEnumerable<IFilterDescriptor> filterDescriptors)Parameters
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System. The source. |
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System. The filter descriptors. |
Returns
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System. An System. |
Where(IQueryable, Expression)
Filters a sequence of values based on a predicate.
Declaration
public static IQueryable Where(this IQueryable source, Expression predicate)Parameters
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System. An System. |
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System. A function to test each element for a condition. |
Returns
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System. An System. |
Where(IQueryable, CompositeFilterDescriptorCollection)
Filters a sequence of values based on a Composite
Declaration
public static IQueryable Where(this IQueryable source, CompositeFilterDescriptorCollection filterDescriptors)Parameters
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System. The source. |
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Composite The composite filter descriptor collection. |
Returns
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System. An System. |
Where(IQueryable, FilterDescriptorCollection)
Filters a sequence of values based on a collection of IFilter
Declaration
public static IQueryable Where(this IQueryable source, FilterDescriptorCollection filterDescriptors)Parameters
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System. The source. |
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Filter The filter descriptors. |
Returns
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System. An System. |