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ObservableAsync.SingleAsync(IObservableAsync, Func) method¶
Defined in
Type: ObservableAsync
Namespace: ReactiveUI.Extensions.Async
Assembly: ReactiveUI.Extensions.dll
Applies to
net10.0, net10.0-browserwasm1.0, net10.0-desktop1.0, net9.0, net9.0-browserwasm1.0, net9.0-desktop1.0, net8.0, net8.0-ios17.5, net8.0-maccatalyst17.5, net8.0-macos14.2, net8.0-macos14.5, net8.0-tvos17.2, netstandard2.1, net462, net481
Overloads¶
- 1.
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this, Func<T, bool> predicate) - 2.
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this, Func<T, bool> predicate, CancellationToken cancellationToken) - 3.
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this) - 4.
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this, CancellationToken cancellationToken)
1. Overload¶
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this, Func<T, bool> predicate)
Summary: Asynchronously returns the single element of a sequence that satisfies a specified condition, or throws an exception if more than one such element exists.
Type parameters
| Name | Description |
|---|---|
T | The type of elements in the source sequence. |
Parameters
| Name | Type | Description |
|---|---|---|
this | [IObservableAsync | The source observable sequence. |
predicate | Func | A function to test each element for a condition. The method returns the element for which this predicate returns true. |
Returns: ValueTask
Remarks
If no element satisfies the condition, or if more than one element satisfies the condition, an exception is thrown. Use this method when exactly one element is expected to match the predicate.
2. Overload¶
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this, Func<T, bool> predicate, CancellationToken cancellationToken)
Summary: Asynchronously returns the single element of a sequence that satisfies a specified condition, or throws an exception if more than one such element exists.
Type parameters
| Name | Description |
|---|---|
T | The type of elements in the source sequence. |
Parameters
| Name | Type | Description |
|---|---|---|
this | [IObservableAsync | The source observable sequence. |
predicate | Func | A function to test each element for a condition. The method returns the element for which this predicate returns true. |
cancellationToken | CancellationToken | A cancellation token that can be used to cancel the asynchronous operation. |
Returns: ValueTask
Remarks
If no element satisfies the condition, or if more than one element satisfies the condition, an exception is thrown. Use this method when exactly one element is expected to match the predicate.
3. Overload¶
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this)
Summary: Asynchronously returns the single element of the sequence, and throws an exception if the sequence does not contain exactly one element.
Type parameters
| Name | Description |
|---|---|
T | The type of elements in the source sequence. |
Parameters
| Name | Type | Description |
|---|---|---|
this | [IObservableAsync | The source observable sequence. |
Returns: ValueTask
Remarks
Use this method when you expect the sequence to contain exactly one element. If the sequence is empty or contains more than one element, an exception is thrown.
4. Overload¶
public static ValueTask<T> SingleAsync<T>(this IObservableAsync<T> @this, CancellationToken cancellationToken)
Summary: Asynchronously returns the single element of the sequence, and throws an exception if the sequence does not contain exactly one element.
Type parameters
| Name | Description |
|---|---|
T | The type of elements in the source sequence. |
Parameters
| Name | Type | Description |
|---|---|---|
this | [IObservableAsync | The source observable sequence. |
cancellationToken | CancellationToken | A cancellation token that can be used to cancel the asynchronous operation. |
Returns: ValueTask
Remarks
Use this method when you expect the sequence to contain exactly one element. If the sequence is empty or contains more than one element, an exception is thrown.