c# - How do I turn this synchronous method into one that returns a Task? -

i have method more or less calls 3 different async methods , returns "result" object containing success message. of 3 async methods may throw sshexception, i've placed 3 within try{}catch{} traps aggregateexception, handles sshexception, , returns failure result object.

since i'm on .net 4.0, can't use async/await (which believe solve problem easily), turn method 1 returns task containing 1 of 2 results:

1. "success" if 3 previous tasks completed successfully.
2. "failure" if any of previous tasks faulted. ideally, task execution stop @ first canceled task (e.g. taskcontinuationoptions.notonfaulted 3 work tasks).

here's sample code:

public uploadresult uploadfiletodir(string dir, string text) {     try     {         sftpclient.cd(dir).wait();  // task         var filename = this.getfilename().result;  // task         sftpclient.writefile(filename, text).result;  // last task         return uploadresult.success;     }     catch(aggregateexception agg)     {         if(agg.innerexception sshexception)         {             return uploadresult.failure;         }         throw;     } } 

i recommend using microsoft.bcl.async allows use async/await in .net 4 projects. allow write:

public async task<uploadresult> uploadfiletodir(string dir, string text) {     try     {         await sftpclient.cd(dir)         var filename = await this.getfilename();         await sftpclient.writefile(filename, text);         return uploadresult.success;     }     catch(sshexception ex)     {         return uploadresult.failure;     } } 

without that, you'd have make each task run continuation on previous, , return final task continuation, or take existing code , wrap in task.factory.startnew call (which isn't either, you're doing async on sync on async, inefficient). creates lot of code, , makes overall flow more difficult follow.