async-await

问题 It's recommended that one use ConfigureAwait(false) whenever when you can, especially in libraries because it can help avoid deadlocks and improve performance. I have written a library that makes heavy use of async (accesses web services for a DB). The users of the library were getting a deadlock and after much painful debugging and tinkering I tracked it down to the single use of await Task.Yield() . Everywhere else that I have an await, I use .ConfigureAwait(false) , however that is not

问题 I am trying to use NetworkStream.ReadAsync() to read data but I cannot find how to cancel the ReadAsync() once called. For background, the NetworkStream is provided to me by a connected BluetoothClient object (from 32Feet.NET Bluetooth Library). The current get-it-working code I'm trying is below. int bytesRead; while (this.continueReading) { bytesRead = await this.stream.ReadAsync(this.buffer, 0, (int)this.buffer.Length); Console.WriteLine("Received {0} bytes", bytesRead); } Console

问题 Inside of an RxJS subject's subscribe callback, I want to await on an async function. Below is a code example which the typescript transpiler complains about saying: Error:(131, 21) TS2304:Cannot find name 'await'. async ngOnInit() { this.subscriber = dateSubscription.subscribe((date: Date) => { let dbKey = await this._someService.saveToDatabase(someObject); // wait for db write to finish before evaluating the next code // ... some other code here }); } Usually I see this when trying to call

问题 Inside of an RxJS subject's subscribe callback, I want to await on an async function. Below is a code example which the typescript transpiler complains about saying: Error:(131, 21) TS2304:Cannot find name 'await'. async ngOnInit() { this.subscriber = dateSubscription.subscribe((date: Date) => { let dbKey = await this._someService.saveToDatabase(someObject); // wait for db write to finish before evaluating the next code // ... some other code here }); } Usually I see this when trying to call

问题 Inside of an RxJS subject's subscribe callback, I want to await on an async function. Below is a code example which the typescript transpiler complains about saying: Error:(131, 21) TS2304:Cannot find name 'await'. async ngOnInit() { this.subscriber = dateSubscription.subscribe((date: Date) => { let dbKey = await this._someService.saveToDatabase(someObject); // wait for db write to finish before evaluating the next code // ... some other code here }); } Usually I see this when trying to call

问题 Let say I have an async method: public async Task Do() { await Task.Delay(1000); } Another method is trying to call Do method inside catch block public async Task DoMore() { try { } catch (Exception) { await Do(); //compiled error. } } But this way, the compiler does not allow using await inside catch , is there any reason behind the scene why we could not use it that way? 回答1: Update This will be supported in C# 6. It turned out that it wasn't fundamentally impossible, and the team worked

问题 I'd like to just punt a call over to the SQL Server and not wait for a return. I have an imported Entity Function from a Stored Procedure that I'd like to call asynchronously this way in Entity Framework 6.0.0-rc1. Is this possible? What's the syntax? Entity Function: RecalculateBudgetNumbers(int id) 回答1: Start a new Task that creates a fresh data context and invokes that function. Just don't wait/await that task. Let it run by itself to completion. Make sure to log errors. Don't swallow

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 2 years ago . I'm trying to fully understand async - await and one of the gaps in my understanding is seeing what is "All the Way Down." I create an async method, it is called by another async method, etc., all the way down to something that I understand in vague terms like "a UI" or "a web server that can

问题 I'm creating my first app using Node.js and PostgreSQL. This app connect to db, create table, do web scraping of a web site, insert info to db and then disconnect from db. I'm trying to do using async/await . The problem is that the insert operation doesn't work. There is no errors, simply table coverages remains empty. This is my code. app.js : const postgreSQLlib = require('./middlewares/postgreSQLlib.js') const scraper = require('./routers/scraper.js'); const start = async function() {

问题 This question already has answers here : How to write a async method with out parameter? (11 answers) Closed 4 months ago . I'm looking for recommendations on how to handle the following situation. I'm creating methods for trying to get at some data, following this pattern: // Typical pattern public bool TryBlah(string key, out object value) { // ... set value and return boolean } I've run into an issue when trying to follow this pattern on they async versions because you cannot use out on