Returns an enumerable sequence if the evaluation result of the given condition is true, otherwise returns an empty sequence.

Namespace: System.Linq
Assembly: System.Interactive (in System.Interactive.dll)

public static IEnumerable<TResult> If<TResult>(
	Func<bool> condition,
	IEnumerable<TResult> thenSource
)

Type: System.Func<Boolean>
Condition to evaluate.

Type: System.Collections.Generic.IEnumerable<TResult>
Sequence to return in case the condition evaluates true.

Result sequence element type.

Type: IEnumerable<TResult>
The given input sequence if the condition evaluates true; otherwise, an empty sequence.

EnumerableEx Class
System.Linq Namespace