asynchronous

问题 Follow-on question to this one. I am trying to generate and save a series of images. Rendering is done by Helix Toolkit, which I am told utilises the WPF composite render thread. This is causing problems because it executes asynchronously. My original problem was that I couldn't save a given image because it hadn't yet been rendered at that time I was trying to save it. The above answer provides a workaround to this by putting the 'save' operation inside an Action which is called with low

问题 List item I'm trying to send a JPG image (captured by ImagePicker in emulator) via HTTP POST with base64 encoding to an AWS REST API. But readAsBytesSync() operation only reads a (head) part of the image (I've tested it printing to the string as bytes) thus base64 can only encode that small part. What may be the reason, many thanks for your help in advance. Future<void> captureImage(ImageSource imageSource) async { try { ImagePicker picker = ImagePicker(); final pickedFile = await picker

问题 const startLive = () => { // connect to websocket only on start button setliveChartState({ ...liveChartState, liveActive: !liveChartState.liveActive, historicLiveActive: true, start: new Date(), }); /*- - - -after updation - - - >*/ const { ws, liveActive } = liveChartState; // if clicked on stop then close websocket if (!liveActive && ws) { ws.close(); clearLiveInterval(); } // if clicked on start and websocket close then connect if ((!ws || ws.readyState === WebSocket.CLOSED)&& liveActive)

问题 I want to write an async-await method with a return value, but my code doesn't work. I also tried another way such as DispatchQueue.global DispatchGroup() and so on. Here is my code: func checkPassCode() -> Bool { var result = false let closure = { (_ flag:Bool) -> Void in result = flag } if var pin = self.keychain.get("pin") { let userPin = self.pin.joined(separator: "") let encryptedData = NSData(base64Encoded: pin, options: []) AsymmetricCryptoManager.sharedInstance

问题 I'm trying to return a UserDetail object which consists of a User and Results, User is retrieved via the accessToken of Account (all retrieved via individual async calls). At the moment I'm stuck at figuring out how I can return this UserDetail object when I navigate to the detailcomponent (I know it is not possible to literally return the object since the call is async, but I need to use this object in my component). The code below gives me the following error: Type 'Observable' is not

问题 I have a async map function but want it to execute synchronously because I need the output of the first statement to be used within the same loop. But the map runs asynchronously even with await statements, can you please help understand why this happens. My use case if to insert a record into mongodb if not present and update it if present in a loop. The data exists in the db but find fails within the loop but works outside. My code: const doSomethingAsync = () => { return new Promise

问题 I've been watching all morning because this code doesn't work for me. I want once the promise is resolved, the "then" get its last inserted ID (the promise) and neatly insert into the other table. Currently first paints all the promise and then just then or disorderly ... con.query("SELECT ID FROM wp_posts ORDER BY ID DESC LIMIT 0,1;", function(err, result, fields) { console.log(result); for (var i = 0; i < getData.length; i++) { var source = getData[i]["source"]; var text = getData[i]["text"

问题 How can I write into a TextBlock on a different page? So far it only works with TextBlocks on the same page. The async function is in Page_1 . The TextBlock is on Page_2 . public async void Serial() { string rxBuffer; //code //code //code while (true) { textblock_DebugRx_Gas_live.Text = rxBuffer; } } 回答1: write string to textblock on different page in C#, UWP If the two page display in foreground at same time like following. <Grid> <Grid.RowDefinitions> <RowDefinition Height="1*"/>

问题 In my header component, I have conditional rendering set to display different links depending on if the user is logged in or not. The conditional rendering works fine EXCEPT the fact that it blinks one set of links before displaying the proper set of links. It dawned on me this is because of the axios.get call I have that retrieves the user's status. The state variable is initially set to false. If the user is logged in, the get call will indicate that and the state variable will get set to

问题 This question already has an answer here : TCP Socket is not stopping receiving data in C# program (1 answer) Closed 21 days ago . I'm having an issue with my Sockets. Basically I have a few listeners that listen on all the available ports on my pc. When a socket connects to one of the listeners, I open a new Socket-connection to handle that connection and my listener goes back to listening. However when a client disconnects I keep on receiving empty data. As you can see in the code below, I