Observable.ToList<TSource> Method
Creates a list from an observable sequence.
Namespace: System.Reactive.Linq
Assembly: System.Reactive (in System.Reactive.dll)
Syntax
'Declaration
<ExtensionAttribute> _
Public Shared Function ToList(Of TSource) ( _
source As IObservable(Of TSource) _
) As IObservable(Of IList(Of TSource))
'Usage
Dim source As IObservable(Of TSource)
Dim returnValue As IObservable(Of IList(Of TSource))
returnValue = source.ToList()
public static IObservable<IList<TSource>> ToList<TSource>(
this IObservable<TSource> source
)
[ExtensionAttribute]
public:
generic<typename TSource>
static IObservable<IList<TSource>^>^ ToList(
IObservable<TSource>^ source
)
static member ToList :
source:IObservable<'TSource> -> IObservable<IList<'TSource>>
JScript does not support generic types and methods.
Type Parameters
- TSource
The type of source.
Parameters
- source
Type: System.IObservable<TSource>
The source observable sequence to get a list of elements for.
Return Value
Type: System.IObservable<IList<TSource>>
A list from an observable sequence.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IObservable<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see or .
Remarks
The ToList operator takes all the items in the sequence and puts them in a list. Then the list is returned as an observable sequence (IObservable<IList<TSource>>). The return value of this operator differs from the corresponding operator on IEnumerable in order to retain asynchronous behavior.
Examples
The following example uses the Generate operator to generate a simple sequence of the integers (1-10). Then, the ToList operator is used to convert that sequence to a list. The IList.Add method is used to 9999 to the resulting list before each item in the list is written to the console window.
using System;
using System.Reactive.Linq;
using System.Collections;
namespace Example
{
class Program
{
static void Main()
{
//*********************************************//
//*** Generate a sequence of integers 1-10 ***//
//*********************************************//
var obs = Observable.Generate(1, // Initial state value
x => x <= 10, // The termination condition. Terminate generation when false (the integer squared is not less than 1000)
x => ++x, // Iteration step function updates the state and returns the new state. In this case state is incremented by 1
x => x); // Selector function determines the next resulting value in the sequence. The state of type in is squared.
//***************************************************************************************************//
//*** Convert the integer sequence to a list. Use the IList.Add() method to add 9999 to the list ***//
//***************************************************************************************************//
var obsList = obs.ToList();
obsList.Subscribe(x =>
{
x.Add(9999);
//****************************************//
//*** Enumerate the items in the list ***//
//****************************************//
foreach (int val in x)
{
Console.WriteLine(val);
}
});
Console.WriteLine("\nPress ENTER to exit...\n");
Console.ReadLine();
}
}
}
The following output was generated with the example code.
1
2
3
4
5
6
7
8
9
10
9999
Press ENTER to exit...