Await in catch block

Question

I have the following code:

WebClient wc = new WebClient();
string result;
try
{
  result = await wc.DownloadStringTaskAsync( new Uri( \"http://badurl\" ) );
         


        

Answer 1

You can use a lambda expression as follows:

  try
    {
        //.....
    }
    catch (Exception ex)
    {
        Action<Exception> lambda;

        lambda = async (x) =>
        {
            // await (...);
        };

        lambda(ex);
    }

Answer 2

In a similar instance, I was unable to await in a catch block. However, I was able to set a flag, and use the flag in an if statement (Code below)

---------------------------------------...

boolean exceptionFlag = false; 

try 
{ 
do your thing 
} 
catch 
{ 
exceptionFlag = true; 
} 

if(exceptionFlag == true){ 
do what you wanted to do in the catch block 
}

Answer 3

This seems to work.

        WebClient wc = new WebClient();
        string result;
        Task<string> downloadTask = wc.DownloadStringTaskAsync(new Uri("http://badurl"));
        downloadTask = downloadTask.ContinueWith(
            t => {
                return wc.DownloadStringTaskAsync(new Uri("http://google.com/")).Result;
            }, TaskContinuationOptions.OnlyOnFaulted);
        result = await downloadTask;

Answer 4

Awaiting in a catch block is now possible as of the End User Preview of Roslyn as shown here (Listed under Await in catch/finally) and will be included in C# 6.

The example listed is

try … catch { await … } finally { await … }

Update: Added newer link, and that it will be in C# 6

Answer 5

Give this a try:

         try
        {
            await AsyncFunction(...);
        }

        catch(Exception ex)
        { 
            Utilities.LogExceptionToFile(ex).Wait();
            //instead of "await Utilities.LogExceptionToFile(ex);"
        }

(See the Wait() ending)

Answer 6

Use C# 6.0. see this Link

public async Task SubmitDataToServer()
{
  try
  {
    // Submit Data
  }
  catch
  {
    await LogExceptionAsync();
  }
  finally
  {
    await CloseConnectionAsync();
  }
}