/
Program.cs
104 lines (92 loc) · 2.51 KB
/
Program.cs
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Console.WriteLine("Starting example...");
var raisingObject = new RaisingObject();
#region Base Case
//raisingObject.Event += async (s, e) =>
//{
// Console.WriteLine("Starting the event handler...");
// await TaskThatThrowsAsync();
// Console.WriteLine("Event handler completed.");
//};
#endregion
#region Solution 1
//raisingObject.Event += async (s, e) =>
//{
// Console.WriteLine("Starting the event handler...");
// try
// {
// await TaskThatThrowsAsync();
// }
// catch (Exception ex)
// {
// Console.WriteLine($"[Inside Event Handler] Our exception handler caught: {ex}");
// }
// Console.WriteLine("Event handler completed.");
//};
#endregion
#region Solution 2
raisingObject.Event += EventHandlers.TryAsync<EventArgs>(
async (s, e) =>
{
Console.WriteLine("Starting the event handler...");
await TaskThatThrowsAsync();
Console.WriteLine("Event handler completed.");
},
ex => Console.WriteLine($"[TryAsync Error Callback] Our exception handler caught: {ex}"));
#endregion
try
{
Console.WriteLine("Raising our event...");
raisingObject.Raise(EventArgs.Empty);
}
catch (Exception ex)
{
Console.WriteLine($"Our exception handler caught: {ex}");
}
Console.WriteLine("Example complete.");
async Task TaskThatThrowsAsync()
{
Console.WriteLine("Starting task that throws async...");
throw new InvalidOperationException("This is our exception");
};
class RaisingObject
{
// you could in theory have your own event args here
public event EventHandler<EventArgs> Event;
public void Raise(EventArgs e)
{
Event?.Invoke(this, e);
}
}
#region Wrapper Solution
static class EventHandlers
{
public static EventHandler<TArgs> TryAsync<TArgs>(
Func<object, TArgs, Task> callback,
Action<Exception> errorHandler)
where TArgs : EventArgs
=> TryAsync<TArgs>(
callback,
ex =>
{
errorHandler.Invoke(ex);
return Task.CompletedTask;
});
public static EventHandler<TArgs> TryAsync<TArgs>(
Func<object, TArgs, Task> callback,
Func<Exception, Task> errorHandler)
where TArgs : EventArgs
{
return new EventHandler<TArgs>(async (object s, TArgs e) =>
{
try
{
await callback.Invoke(s, e);
}
catch (Exception ex)
{
await errorHandler.Invoke(ex);
}
});
}
}
#endregion