c# - Wrap async lambda to the async method -

i'm trying wrap operations contracts try-catch block. problem ef context destroyed in same time scope. guess problem compiler doesn't know properly. catch block doesn't handle exceptions. sorry english, hope code show mean:

private static async task<t> surroundwithtrycatch<t>(action t, t response) t : baseresponse  {     try     {         await task.run(t);     }     catch (exception e)     {         response.success = false;         response.errors.add(e.message);     }     return response; }  public async task<createresponse> createasync(createrequest request) {     var response = new createresponse();     return await surroundwithtrycatch(async delegate     {         var newuser = new applicationuser { username = request.username, email = request.email };         await database.usermanager.createasync(newuser, request.password);         //some logic...         await database.commitasync();     }, response); } 

the problem in second line of createasync method. usermanager cleaned gc earlier. have objectdisposedexception. database iunitofwork implementation , injected autofac.

you're breaking await chain - t no longer returns task. since no longer have task, execution continue after first await, rather after whole method done. think of await return - if don't return (and await/wait for) task, lose chance @ synchronization.

instead, want pass func<task>, , await directly:

private static async task<t> surroundwithtrycatch<t>(func<task> t, t response) t : baseresponse  {     try     {         await t();     }     catch (exception e)     {         response.success = false;         response.errors.add(e.message);     }     return response; }  public async task<createresponse> createasync(createrequest request) {     var response = new createresponse();     return await surroundwithtrycatch(async () =>     {         var newuser = new applicationuser { username = request.username, email = request.email };         await database.usermanager.createasync(newuser, request.password);         //some logic...         await database.commitasync();     }, response); } 

task.run works, don't want anyway - code asynchronous, , (a guess) you're running in asp.net request, there's no benefit launching task wait on result of task. task.run used doing cpu work in separate thread, want avoid in asp.net.