.net - C# async await using LINQ ForEach() -

i have following code correctly uses async/await paradigm.

internal static async task addreferencsedata(configurationdbcontext context) {     foreach (var sinkname in requiredsinktypelist)     {         var sinktype = new sinktype() { name = sinkname };         context.sinktypecollection.add(sinktype);         await context.savechangesasync().configureawait(false);     } } 

what equivalent way write if, instead of using foreach(), want use linq foreach()? one, example, gives compile error.

internal static async task addreferencedata(configurationdbcontext context) {     requiredsinktypelist.foreach(         sinkname =>         {             var sinktype = new sinktype() { name = sinkname };             context.sinktypecollection.add(sinktype);             await context.savechangesasync().configureawait(false);         }); } 

the code got work without compile error this.

internal static void addreferencedata(configurationdbcontext context) {     requiredsinktypelist.foreach(         async sinkname =>         {             var sinktype = new sinktype() { name = sinkname };             context.sinktypecollection.add(sinktype);             await context.savechangesasync().configureawait(false);         }); } 

i'm worried method has no async signature, body does. correct equivalent of first block of code above?

no. isn't. foreach doesn't support async-await , requires lambda async void should only used event handlers. using run async operations concurrently , won't wait them complete.

you can use regular foreach did if want extension method need special async version.

you can create 1 iterates on items, executes async operation , awaits it:

public async task foreachasync<t>(this ienumerable<t> enumerable, func<t, task> action) {     foreach (var item in enumerable)     {         await action(item);     } } 

usage:

internal static async task addreferencsedata(configurationdbcontext context) {     await requiredsinktypelist.foreachasync(async sinkname =>     {         var sinktype = new sinktype() { name = sinkname };         context.sinktypecollection.add(sinktype);         await context.savechangesasync().configureawait(false);     }); } 

a different (and more efficient) implementation of foreachasync start async operations , await of them that's possible if actions can run concurrently isn't case (e.g. entity framework):

public task foreachasync<t>(this ienumerable<t> enumerable, func<t, task> action) {     return task.whenall(enumerable.select(item => action(item))); } 

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as noted in comments don't want use savechangesasync in foreach begin with. preparing changes , saving them @ once more efficient.