<PackageReference Include="Polly" Version="7.2.3" />

AsyncFallbackSyntax

public static class AsyncFallbackSyntax
Fluent API for defining a Fallback AsyncPolicy.
using Polly.Fallback; using Polly.Utilities; using System; using System.Threading; using System.Threading.Tasks; namespace Polly { public static class AsyncFallbackSyntax { public static AsyncFallbackPolicy FallbackAsync(this PolicyBuilder policyBuilder, Func<CancellationToken, Task> fallbackAction) { if (fallbackAction == null) throw new ArgumentNullException("fallbackAction"); Func<Exception, Task> onFallbackAsync = (Exception _) => TaskHelper.EmptyTask; return policyBuilder.FallbackAsync(fallbackAction, onFallbackAsync); } public static AsyncFallbackPolicy FallbackAsync(this PolicyBuilder policyBuilder, Func<CancellationToken, Task> fallbackAction, Func<Exception, Task> onFallbackAsync) { if (fallbackAction == null) throw new ArgumentNullException("fallbackAction"); if (onFallbackAsync == null) throw new ArgumentNullException("onFallbackAsync"); return policyBuilder.FallbackAsync((Exception _, Context _, CancellationToken ct) => fallbackAction(ct), (Exception outcome, Context _) => onFallbackAsync(outcome)); } public static AsyncFallbackPolicy FallbackAsync(this PolicyBuilder policyBuilder, Func<Context, CancellationToken, Task> fallbackAction, Func<Exception, Context, Task> onFallbackAsync) { if (fallbackAction == null) throw new ArgumentNullException("fallbackAction"); if (onFallbackAsync == null) throw new ArgumentNullException("onFallbackAsync"); return policyBuilder.FallbackAsync((Exception _, Context ctx, CancellationToken ct) => fallbackAction(ctx, ct), onFallbackAsync); } public static AsyncFallbackPolicy FallbackAsync(this PolicyBuilder policyBuilder, Func<Exception, Context, CancellationToken, Task> fallbackAction, Func<Exception, Context, Task> onFallbackAsync) { if (fallbackAction == null) throw new ArgumentNullException("fallbackAction"); if (onFallbackAsync == null) throw new ArgumentNullException("onFallbackAsync"); return new AsyncFallbackPolicy(policyBuilder, onFallbackAsync, fallbackAction); } } }