Await in catch and finally
suggest changeIt is possible to use await
expression to apply await operator to Tasks or Task(Of TResult) in the catch
and finally
blocks in C#6.
It was not possible to use the await
expression in the catch
and finally
blocks in earlier versions due to compiler limitations. C#6 makes awaiting async tasks a lot easier by allowing the await
expression.
try
{
//since C#5
await service.InitializeAsync();
}
catch (Exception e)
{
//since C#6
await logger.LogAsync(e);
}
finally
{
//since C#6
await service.CloseAsync();
}
It was required in C# 5 to use a bool
or declare an Exception
outside the try catch to perform async operations. This method is shown in the following example:
bool error = false;
Exception ex = null;
try
{
// Since C#5
await service.InitializeAsync();
}
catch (Exception e)
{
// Declare bool or place exception inside variable
error = true;
ex = e;
}
// If you don't use the exception
if (error)
{
// Handle async task
}
// If want to use information from the exception
if (ex != null)
{
await logger.LogAsync(e);
}
// Close the service, since this isn't possible in the finally
await service.CloseAsync();
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