c# - Trying to use async method TextReader.ReadBlockAsync, but getting "the 'await' operator can only be used within an async method" -

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• issue regarding asynchronous programming async , await c# [duplicate] 2 answers

i want call asynchronous reader method of textreader, compile error:

var buffer = new char[10];  textreader reader = new streamreader(@"d:\temp\abc.txt");  // following statement compile error var readcount = await reader.readblockasync(buffer, 0, buffer.length); 

this error:

the 'await' operator can used within async method. consider marking method 'async' modifier , changing return type 'task'.

what right way use readblockasync?

you need mark method async identifier mentioned others. method needs return task, task<t> or void. void returning async methods reserved async event handlers. in case you'd want return task<string>

public async task<string> readasync() {     var buffer = new char[10];      textreader reader = new streamreader(@"d:\temp\abc.txt");      var readcount = await reader.readblockasync(buffer, 0, buffer.length);        return new string(buffer.take(readcount).toarray()); } 

you may find following resources useful: best practices async/await, asynchronous programming async-await