HttpClient->GetStringAsync() throws 0x000006F4 for https Uris - https

The code below works fine for me if I use an http URI, but fails for equivalent https alternative. It works fine when built and run on another machine or when I include it in another app.
GetStringAsync throws an exception: “Exception thrown at 0x770B5722 (KernelBase.dll) in .exe: 0x000006F4: A null reference pointer was passed to the stub. occurred”.
ThreadPool::RunAsync(ref new WorkItemHandler([this](IAsyncAction^ action)
{
HttpClient^ client = ref new HttpClient();
auto uri = ref new Uri(L"https://....");
auto t = create_task(client->GetStringAsync(uri));
t.then([](String^ response)
{
// response should be valid.
});
}));

Running netsh winsock reset to reset the network stack seems to fix the issue!

For me, network stack reset didn't help at all, even device reboot didn't help, but your own answer have pointed me in the right direction: it wasn't my code who suddendly went mad, it was Windows. So what actually helped in my case is starting app without debugger (that is, from Start menu) - after that app continues to work fine when started from Visual Studio. It have happened a few times now, and I can confirm that it always helps.

Related

Uncaught Error: Returned values aren't valid, did it run Out of Gas?

I'm listening to events of my deployed contract. Whenever a transaction gets completed and event is fired receiving the response causes following error:
Uncaught Error: Returned values aren't valid, did it run Out of Gas?
at ABICoder.push../node_modules/web3-eth-abi/src/index.js.ABICoder.decodeParameters
(index.js:227)
at ABICoder.push../node_modules/web3-eth-abi/src/index.js.ABICoder.decodeLog
(index.js:277)
Web3 version: 1.0.0-beta36
Metamask version: 4.16.0
How to fix it?
Try the command truffle migrate --reset so that all the previous values are reset to their original value
Throws the same error when inside a transaction it generates different events with the same name and the same arguments. In my case, this was the Transfer event from ERC721 and ERC20. Renaming one of them solves this problem, but of course this isn't the right way.
This is a bug in web3js, discussed here.
And the following change fixes it (source):
patch-package
--- a/node_modules/web3-eth-abi/src/index.js
+++ b/node_modules/web3-eth-abi/src/index.js
## -280,7 +280,7 ## ABICoder.prototype.decodeLog = function (inputs, data, topics) {
var nonIndexedData = data;
- var notIndexedParams = (nonIndexedData) ? this.decodeParameters(notIndexedInputs, nonIndexedData) : [];
+ var notIndexedParams = (nonIndexedData && nonIndexedData !== '0x') ? this.decodeParameters(notIndexedInputs, nonIndexedData) : [];
var returnValue = new Result();
returnValue.__length__ = 0;
Edit: Also downgrading to web3-1.0.0.beta33 also fixes this issue too.
Before even checking your ABI or redeploying, check to make sure Metamask is connected to whichever network your contract is actually deployed too. I stepped away and while i was afk Metamask logged out, I guess I wasn't watching closely and I was connected to Ropsten when I working on localhost. Simple mistake, wasted an hour or so trying to figure it out. Hope this helps someone else out!
This happened to me on my react app.
I deployed to contract to Ropsten network, but metamask was using the Rinkeby aaccount. So make sure whichever network you deployed, metamask should be using account from that network.
The solution for me was changing of provider. With Infura the error is gone, but with Alchemy is still happening.
Please check your Metamask Login, This issue is generally populated when you are either log out of the Metamask or worse case you have 0 ether left at your account.
This can also happen when the MNEMONIC value from Ganache is different from the one you have in your truffle.js or truffle-config.js file.

Accessing Webapi on Localhost on Dev Machine from Android Emulator

This may well be a duplicate question, but no answer from an existing question has solved my problem.
I have a WebAPI end point running on my dev machine. I've configured it to run on
.UseUrls("http://localhost:57971", "http://10.0.2.2:57971", "http://192.168.44.1:57971", "http://192.168.1.48:57971", "http://*:57971")
where:
192.168.44.1 is Desktop Adapter #2 on the emulator Networks settings tab
10.0.2.2 is the special address for the Android emulator, as set out in Google's doco (possibly not relevant to Xamarin) and
192.168.1.48 is my local IP address for my dev machine.
I have created a firewall rule permitting connections on TCP port 57971.
I researched this pretty heavily and heeded instructions such as those set out here http://briannoyesblog.azurewebsites.net/2016/03/06/calling-localhost-web-apis-from-visual-studio-android-emulator/
I'm kinda out of ideas. The annoying thing is, it fails silently. There is no exception and the output just basically shows the different threads exiting with code 0. And the application keeps running i.e. the debugging session is not returning the IDE to a "code entry" state. This may suggest that something else its at play here.
The code looks pretty innocuous to me:
protected async Task<T> GetAsync<T>(string url)
where T : new()
{
HttpClient httpClient = CreateHttpClient();
T result;
try
{
var response = await httpClient.GetStringAsync(url);
result = await Task.Run(() => JsonConvert.DeserializeObject<T>(response));
}
catch
{
result = new T();
}
return result;
}
I'm using Visual Studio 2015.
I'm using the Visual Studio emulator https://www.visualstudio.com/vs/msft-android-emulator/
Any idea how I can get wheels on the ground on this thing?
Is there a way to Ping my machine from the emulator?
Thanks
I got this working by using 169.254.80.80 i.e. I added it to the list of urls which the API serves and called that ip address from the Xamarin app.
So, in Program.cs became simple:
.UseUrls("http://localhost:57971", "http://169.254.80.80:57971")
I also had to add it to the bindings element ApplicationConfig file in the hidden .vs folder of the ASP.NET API solution. Not sure why it had to be 169.254.80.80, as that was Desktop Adapter #4.
That got it working.

SignalR Hub method is not called

I have a SignalR hub and two clients (Windows and PCL for Android and iOS). Neither of the clients is able to call some methods on the server. This behaviour is quite odd, since the methods look very similar. Moreover, a colleague of mine is able to call methods I cannot call, and vice versa, does not invoke methods that I invoke with no problems.
Here is an example of a method, which works for me and does not work for my colleague:
public override async Task<bool> RefreshArray(User user, int waitMilis)
{
var cts = new CancellationTokenSource();
try
{
cts.CancelAfter(waitMilis);
await Proxy.Invoke("RefreshArray", user);
return true;
}
catch (Exception ex)
{
OnExceptionOccured(ex);
return false;
}
}
And a method which does not work for me, but works for my colleague:
public override async Task<bool> RequestInformation(User user, Product product, int waitMilis)
{
var cts = new CancellationTokenSource();
try
{
cts.CancelAfter(waitMilis);
await Proxy.Invoke("RequestInformation", user, product);
return true;
}
catch (Exception ex)
{
OnExceptionOccured(ex);
return false;
}
}
Yes, me and my colleague have exactly the same code. And no, there are no typos or different arguments. I have tried to get as much data from the client connection as possible, by setting _connection.TraceLevel = TraceLevels.All; However, I did not get any information on the invoked methods, just on the replies from the hub. When calling RefreshArray, I got exactly the data I requested. When calling RequestInformation, the debugger never even hit the breakpoint in the hub method and the _connection.Trace displayed only this: 11:22:45.6169660 - 7bc57897-489b-49a2-8459-3fcdb8fcf974 - SSE: OnMessage(Data: {})
Has anybody solved a similar issue? Is there a solution?
UPDATE 1
I just realized that I have encountered almost the same issue about a year ago (Possible SignalR bug in Xamarin Android). StackOverflow has also pointed me to a question with almost the same issue (SignalR on Xamarin.iOS - randomly not able to call Hub method), just related to iOS and Azure. However, I got the same proble even outside Xamarin, on Windows Phone 8.1 and and Windows 10 Universal App. Moreover, I am running the server just locally, so it is not an issue od Azure. Is it really possible, that a 2 years old bug has no solution?
UPDATE 2
I have just created a simple console application with SignalR.Client. In the console application every method worked just fine. Amazingly, also the Windows 10 Universal Application started to behave as expected - every hub method was invoked correctly. Windows Phone 8.1 also improved its behaviour (all hub methods invoked). However, every now and then the connection tried to reconnect periodically (for no apparent reason), leading to Connection started reconnecting before invocation result was received. error. The Android application still behaved as before.
So I tried to replicate my previous steps and created another console application, but this time with SignalR.Client.Portable library. To my dissapointment, there was no change in the Android application behaviour.
Next week we will start to test our application on iOS, so I really wonder what new oddities will we encounter.
I have managed to solve the problem (at least so it seems). As it turned out, there is some weird stuff going around, when an application receives an answer from SignalR hub. It seems as if the HubProxy was blocked for a certain period of time on Android, while it drops the connection and starts to reconnect periodically on Windows Phone, not waiting for an asnwer from the hub.
The implementation of RefreshArray on the hub was something like this:
public async Task RefreshArray(User user)
{
await Clients.Caller.SendArray(_globalArray);
await Clients.Caller.SendMoreInformation(_additionalInfo);
}
Because the method sent two methods as an answer, the client Proxy got stuck and each platform handled it in its own unexpected way. The reason why some methods were called on my computer and not on colleagues was, simply, because we had different position of breakpoints, which enabled the application to resolve at least some requests and responses.
The ultimate solution was to add some synchronization into the invokation of methods. Now my hub calls only await Clients.Caller.SendArray(_globalArray);. This is then handled on the client with a ArraySent(string[] array) event, which then subsequently invokes the SendMoreInformation() method on the hub.

Actionscript 4: NetConnection.connect(...) does not fire a NetStatusEvent event

I downloaded the red5-recorder (http://www.red5-recorder.com/) , which fails to allow me to start recording. After debugging I found that the netconnection, needed to record to a media server, created does not fire a NetStatusEvent event, so essentially it fails silently. I have implemented the connection with the following minimal working example:
trace("make net connection");
nc = new NetConnection();
nc.client = { onBWDone: function():void{ trace("bandwidth check done.") } };
trace("add event listener");
nc.addEventListener(NetStatusEvent.NET_STATUS, function(event:NetStatusEvent) {
trace("handle");
});
trace("connect!");
nc.connect("rtmp://localshost/oflaDemo/test/");
trace("connect done");
The output of this piece of code is:
make net connection
add event listener
connect!
connect done
The actionscript api states that the connect-call always fires such an event:
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/NetConnection.html#includeExamplesSummary
Moreover, the netconnection is not 'connected' (a state of the NetConnection object) 10 seconds after the call. I also took a look at this: NetConnect fails silently in Flash when called from SilverLight But the fix suggested by the author, swapping rtmp and http in the connection uri, do not work. Also, I tested the uri and in fact the exact same code sniplet in a personal project, where it did work. I just can not seem to find why connecting to a media server fails silently in the red5-recorder project.
The awkward part is that if I pass some random string as a conenction uri, still nothing happens (no event, no exception, no crash). Also not setting nc.client becore nc.connect(), which caused exceptions in my experience, did not cause exceptions.
Any suggestions are welcome.
You are setting the address to localshost instead localhost.
nc.connect("rtmp://localshost/oflaDemo/test/");
Correct address:
nc.connect("rtmp://localhost/oflaDemo/test/");

Basic Node.js examples not working on Windows 7

I installed node.js from http://nodejs.org/#download, v0.6.6. I am using Windows 7 32-bit.
I've been going through various tuts online, and want to experiment while doing so, but I cannot seem to get node.js working. Node will run my .js file, but any request from the browser times out.
Here is a typical Hello World example that does not work:
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(1337);
Pointing my browser at 127.0.0.1:1337 or localhost:1337 does not work. The request from the browser times out. I've also tried listen(1337,'0.0.0.0') and listen(1337,'127.0.0.1').
I know the server is running; if I CTRL+C and stop node, the browser immediately comes back with ERR_CONNECTION_RESET.
I also tried running the code in this gist, which will not work: https://gist.github.com/1339846. I end up with the console output "Listening!" and then nothing else.
Furthermore, I have tried different ports, and my firewall is off via
netsh firewall set opmode mode=disable
I tried with firewall totally disabled, and the service stopped. If I check connections using netstat -noa, I can see node has a bunch of connections opened for the browsers, all in state CLOSE_WAIT. So it looks like connections are happening, but node.js just isn't working.
The callback function that is supposed to be initiated by a request never executes - I sprinkled some console.log statements in various areas, and they all execute except any in the callback.
I uninstalled, re-installed, tried a couple previous builds, restarted my machine...nothing.
Any help is appreciated!
UPDATE: I have just about given up. I've tried everything I can think of, and it ended up being easier to run node.js in an instance of Ubuntu in VirtualBox than grasp at straws.
!!!!!! Same problem happened for me....
Here is a solution which I have yet to find anywhere:
Look in Windows Firewall with Advanced Security and see if Evented I/O for V8 JavaScript is blocked or appears two times.
If so unblock it and delete the duplicated entry. If you install/uninstall/install nodeJs, there will be 2 entries.
Also when node first runs the Window Firewall dialog opens asking if you want to allow node to have firewall access. If you press "No" or just close the window without asking, it will create Evented I/O for V8 JavaScript AND IT WILL BE BLOCKED.
I ran into the same problem and after reading through the documentation, I unexpectedly ran into what I believe is the solution. In my instance I was noticing that the incoming requests WERE being delivered to node, but the response was never having its 'end' event triggered. So altering incoming firewall rules in windows did not seem to be related to the problem.
So, http.createServer takes in a single argument - a function which should include a request and response parameter. The request parameter seemed to be where the problem lay. The request parameter is an instance of http.incomingMessage. This class only had like one event type, but it was itself also an implementation of Stream.Readable, which is where I found the 'end' event that wasn't triggered. Really for no other reason that to just test which was the first event not triggered, I just added a listener for another type of event ('readable'), and only added a console.log line to it which made the whole thing work.
So the code looks simply something like this:
var http = require("http");
http.createServer(function (request, response) {
console.log('request');
request.on('readable', function(){
console.log('request readable');
});
request.on("end", function () {
console.log('request end');
response.writeHead(200, {
'Content-Type': 'text/plain'
});
response.end('Hello HTTP!');
});
}).listen(8080);
The above code works, whereas the earlier version below without a 'readable' event listener does not ever respond:
var http = require("http");
http.createServer(function (request, response) {
console.log('request');
request.on("end", function () {
console.log('request end');
response.writeHead(200, {
'Content-Type': 'text/plain'
});
response.end('Hello HTTP!');
});
}).listen(8080);
I am not sure why this works except for a little clue in the documentation which reads:
In some cases, listening for a 'readable' event will cause some data
to be read into the internal buffer from the underlying system, if it
hadn't already.
I just tried it and it works for me. Make sure you are not blocking node with your firewall.
I am using Windows 7 32-bit.
What edition of Windows 7 are you using? Eg. Home Premium, Professional, Ultimate?
A thread on the npm github project mentions similar symptoms while installing nodejs modules using npm, and comments seem to narrow it down to being caused by Windows 7 Professional. It being 32/64-bit doesn't seem to matter.
I am having both the problem you describe, as well as the npm installation problem, and am running on Windows 7 Professional 64-bit.
Using XPMode (a workaround mentioned in the npm thread) has allowed me to workaround both of these issues. Although, I suppose this is just a more Windows-y version of your use of Ubuntu in VirtualBox.
Other workarounds tried without success:
Make/run a Debug build of v0.6.6
Make/run a Debug build of v0.6.5 (actually crashed in startup)
Set various Compatability Modes on the installed node.exe
Prepackaged Windows installer of v0.6.5
Go to "Control Panel\All Control Panel Items\Windows Firewall\Allowed
Programs"
Click Allow Programs
select nodejs from the list.
This fixed all the problems for me
I was having the same problem with this code (Http Server example from this link: http://net.tutsplus.com/tutorials/javascript-ajax/node-js-for-beginners/)
var http = require("http");
http.createServer(function (request, response) {
request.on("end", function () {
response.writeHead(200, {
'Content-Type': 'text/plain'
});
response.end('Hello HTTP!');
});
}).listen(8080);
I tried windows 7 64-bit version, windows XP virtual machine, ubuntu virtual machine ... nothing! It only worked after I commented the "request.on" line. Your example (which doesn't have this line) worked fine for me. I'm using the latest stable build from node.js (v0.10.18 for windows or linux). Hope this helps anyone having trouble with this.

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