Cannot access a disposed object : DataContext
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I'm using TCPClient to connect to device and get some data as a strings, then I'm trying to save data to DB and getting
"Cannot access a disposed object" error."
Maybe problem is because I'm trying to save to DB from async callback function?
Please take a look, here are two functions: first one gets network stream, already connected to the device and starts reading data, second one is callback:
private void ReadDataAsync(NetworkStream nwStream)
{
byte buffer = new byte[1024];
messageStream mStream = new messageStream(nwStream, buffer);
if (nwStream.CanRead)
{
Console.WriteLine("Starting async");
nwStream.BeginRead(buffer, 0, buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
else
{
Console.WriteLine("Cannot read stream");
}
}
private void OnReadEndAsync(IAsyncResult result)
{
String message = "";
messageStream mStream = (messageStream)result.AsyncState;
int incDataSize = mStream.nwStream.EndRead(result);
message = Encoding.ASCII.GetString(mStream.buffer, 0, incDataSize);
List<Event> events = new List<Event>();
events = ProcessMessage(message);
if(events.Any())
_repo.saveEventsToDB(events);
if (mStream.nwStream.CanRead)
{
mStream.nwStream.BeginRead(mStream.buffer, 0, mStream.buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
}
c# .net tcpclient beginread
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
|
show 2 more comments
I'm using TCPClient to connect to device and get some data as a strings, then I'm trying to save data to DB and getting
"Cannot access a disposed object" error."
Maybe problem is because I'm trying to save to DB from async callback function?
Please take a look, here are two functions: first one gets network stream, already connected to the device and starts reading data, second one is callback:
private void ReadDataAsync(NetworkStream nwStream)
{
byte buffer = new byte[1024];
messageStream mStream = new messageStream(nwStream, buffer);
if (nwStream.CanRead)
{
Console.WriteLine("Starting async");
nwStream.BeginRead(buffer, 0, buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
else
{
Console.WriteLine("Cannot read stream");
}
}
private void OnReadEndAsync(IAsyncResult result)
{
String message = "";
messageStream mStream = (messageStream)result.AsyncState;
int incDataSize = mStream.nwStream.EndRead(result);
message = Encoding.ASCII.GetString(mStream.buffer, 0, incDataSize);
List<Event> events = new List<Event>();
events = ProcessMessage(message);
if(events.Any())
_repo.saveEventsToDB(events);
if (mStream.nwStream.CanRead)
{
mStream.nwStream.BeginRead(mStream.buffer, 0, mStream.buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
}
c# .net tcpclient beginread
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
None of this code shows the actual problem, your repository (sigh) has closed the context
– Michael Randall
Jan 4 at 8:11
As written here, your method are not really "async". And your code is not usable as is. But yes, if they are called asynchronously and the _repo field is closed/disposed meanwhile, this is your error. My guess is you don't properly handle lifetime for your dbcontext.
– AFract
Jan 4 at 8:11
find which line causes error. and write on here to get answer from ppl.
– Arphile
Jan 4 at 8:12
Dig around in here_repo.saveEventsToDB(events);work out why you have closed and disposed the context (somwhere else), this will be your answer
– Michael Randall
Jan 4 at 8:17
Thing is, if I call _repo.saveEventsToDB(events) from another place of program, for example, like this: [HttpPost("saveone")] public async Task<IActionResult> saveOne(Event newEvent) { var events = new List<Event>(); events.Add(newEvent); await _repo.saveEventsToDB(events); return Ok(events); }' it works. So i think problem is because I call it from callback function.. Any idea what can I do?
– Денис Пархоменко
Jan 4 at 10:31
|
show 2 more comments
I'm using TCPClient to connect to device and get some data as a strings, then I'm trying to save data to DB and getting
"Cannot access a disposed object" error."
Maybe problem is because I'm trying to save to DB from async callback function?
Please take a look, here are two functions: first one gets network stream, already connected to the device and starts reading data, second one is callback:
private void ReadDataAsync(NetworkStream nwStream)
{
byte buffer = new byte[1024];
messageStream mStream = new messageStream(nwStream, buffer);
if (nwStream.CanRead)
{
Console.WriteLine("Starting async");
nwStream.BeginRead(buffer, 0, buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
else
{
Console.WriteLine("Cannot read stream");
}
}
private void OnReadEndAsync(IAsyncResult result)
{
String message = "";
messageStream mStream = (messageStream)result.AsyncState;
int incDataSize = mStream.nwStream.EndRead(result);
message = Encoding.ASCII.GetString(mStream.buffer, 0, incDataSize);
List<Event> events = new List<Event>();
events = ProcessMessage(message);
if(events.Any())
_repo.saveEventsToDB(events);
if (mStream.nwStream.CanRead)
{
mStream.nwStream.BeginRead(mStream.buffer, 0, mStream.buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
}
c# .net tcpclient beginread
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
I'm using TCPClient to connect to device and get some data as a strings, then I'm trying to save data to DB and getting
"Cannot access a disposed object" error."
Maybe problem is because I'm trying to save to DB from async callback function?
Please take a look, here are two functions: first one gets network stream, already connected to the device and starts reading data, second one is callback:
private void ReadDataAsync(NetworkStream nwStream)
{
byte buffer = new byte[1024];
messageStream mStream = new messageStream(nwStream, buffer);
if (nwStream.CanRead)
{
Console.WriteLine("Starting async");
nwStream.BeginRead(buffer, 0, buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
else
{
Console.WriteLine("Cannot read stream");
}
}
private void OnReadEndAsync(IAsyncResult result)
{
String message = "";
messageStream mStream = (messageStream)result.AsyncState;
int incDataSize = mStream.nwStream.EndRead(result);
message = Encoding.ASCII.GetString(mStream.buffer, 0, incDataSize);
List<Event> events = new List<Event>();
events = ProcessMessage(message);
if(events.Any())
_repo.saveEventsToDB(events);
if (mStream.nwStream.CanRead)
{
mStream.nwStream.BeginRead(mStream.buffer, 0, mStream.buffer.Length,
new AsyncCallback(OnReadEndAsync), mStream);
}
}
c# .net tcpclient beginread
c# .net tcpclient beginread
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
edited Jan 4 at 8:25
Vijunav Vastivch
3,4411724
3,4411724
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
asked Jan 4 at 8:09
Денис ПархоменкоДенис Пархоменко
113
113
None of this code shows the actual problem, your repository (sigh) has closed the context
– Michael Randall
Jan 4 at 8:11
As written here, your method are not really "async". And your code is not usable as is. But yes, if they are called asynchronously and the _repo field is closed/disposed meanwhile, this is your error. My guess is you don't properly handle lifetime for your dbcontext.
– AFract
Jan 4 at 8:11
find which line causes error. and write on here to get answer from ppl.
– Arphile
Jan 4 at 8:12
Dig around in here_repo.saveEventsToDB(events);work out why you have closed and disposed the context (somwhere else), this will be your answer
– Michael Randall
Jan 4 at 8:17
Thing is, if I call _repo.saveEventsToDB(events) from another place of program, for example, like this: [HttpPost("saveone")] public async Task<IActionResult> saveOne(Event newEvent) { var events = new List<Event>(); events.Add(newEvent); await _repo.saveEventsToDB(events); return Ok(events); }' it works. So i think problem is because I call it from callback function.. Any idea what can I do?
– Денис Пархоменко
Jan 4 at 10:31
|
show 2 more comments
None of this code shows the actual problem, your repository (sigh) has closed the context
– Michael Randall
Jan 4 at 8:11
As written here, your method are not really "async". And your code is not usable as is. But yes, if they are called asynchronously and the _repo field is closed/disposed meanwhile, this is your error. My guess is you don't properly handle lifetime for your dbcontext.
– AFract
Jan 4 at 8:11
find which line causes error. and write on here to get answer from ppl.
– Arphile
Jan 4 at 8:12
Dig around in here_repo.saveEventsToDB(events);work out why you have closed and disposed the context (somwhere else), this will be your answer
– Michael Randall
Jan 4 at 8:17
Thing is, if I call _repo.saveEventsToDB(events) from another place of program, for example, like this: [HttpPost("saveone")] public async Task<IActionResult> saveOne(Event newEvent) { var events = new List<Event>(); events.Add(newEvent); await _repo.saveEventsToDB(events); return Ok(events); }' it works. So i think problem is because I call it from callback function.. Any idea what can I do?
– Денис Пархоменко
Jan 4 at 10:31
None of this code shows the actual problem, your repository (sigh) has closed the context
– Michael Randall
Jan 4 at 8:11
None of this code shows the actual problem, your repository (sigh) has closed the context
– Michael Randall
Jan 4 at 8:11
As written here, your method are not really "async". And your code is not usable as is. But yes, if they are called asynchronously and the _repo field is closed/disposed meanwhile, this is your error. My guess is you don't properly handle lifetime for your dbcontext.
– AFract
Jan 4 at 8:11
As written here, your method are not really "async". And your code is not usable as is. But yes, if they are called asynchronously and the _repo field is closed/disposed meanwhile, this is your error. My guess is you don't properly handle lifetime for your dbcontext.
– AFract
Jan 4 at 8:11
find which line causes error. and write on here to get answer from ppl.
– Arphile
Jan 4 at 8:12
find which line causes error. and write on here to get answer from ppl.
– Arphile
Jan 4 at 8:12
Dig around in here
_repo.saveEventsToDB(events); work out why you have closed and disposed the context (somwhere else), this will be your answer– Michael Randall
Jan 4 at 8:17
Dig around in here
_repo.saveEventsToDB(events); work out why you have closed and disposed the context (somwhere else), this will be your answer– Michael Randall
Jan 4 at 8:17
Thing is, if I call _repo.saveEventsToDB(events) from another place of program, for example, like this: [HttpPost("saveone")] public async Task<IActionResult> saveOne(Event newEvent) { var events = new List<Event>(); events.Add(newEvent); await _repo.saveEventsToDB(events); return Ok(events); }' it works. So i think problem is because I call it from callback function.. Any idea what can I do?
– Денис Пархоменко
Jan 4 at 10:31
Thing is, if I call _repo.saveEventsToDB(events) from another place of program, for example, like this: [HttpPost("saveone")] public async Task<IActionResult> saveOne(Event newEvent) { var events = new List<Event>(); events.Add(newEvent); await _repo.saveEventsToDB(events); return Ok(events); }' it works. So i think problem is because I call it from callback function.. Any idea what can I do?
– Денис Пархоменко
Jan 4 at 10:31
|
show 2 more comments
1 Answer
1
active
oldest
votes
Finally found a solution!
So problem was that I used DataContext dependancy, which was injected in the controller constructor - and it was disposed after HTTP request was completed.
So solution is to inject dependancy manually in the function itself, which needs access to the database:
Inject scope factory IServiceScopeFactory scopeFactory in the controller constructor.
Add this to my function where I need access to DBcontext:
using (var scope = _scopeFactory.CreateScope())
{
var context = scope.ServiceProvider.GetRequiredService();
...
}
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
add a comment |
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1 Answer
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votes
Finally found a solution!
So problem was that I used DataContext dependancy, which was injected in the controller constructor - and it was disposed after HTTP request was completed.
So solution is to inject dependancy manually in the function itself, which needs access to the database:
Inject scope factory IServiceScopeFactory scopeFactory in the controller constructor.
Add this to my function where I need access to DBcontext:
using (var scope = _scopeFactory.CreateScope())
{
var context = scope.ServiceProvider.GetRequiredService();
...
}
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
add a comment |
Finally found a solution!
So problem was that I used DataContext dependancy, which was injected in the controller constructor - and it was disposed after HTTP request was completed.
So solution is to inject dependancy manually in the function itself, which needs access to the database:
Inject scope factory IServiceScopeFactory scopeFactory in the controller constructor.
Add this to my function where I need access to DBcontext:
using (var scope = _scopeFactory.CreateScope())
{
var context = scope.ServiceProvider.GetRequiredService();
...
}
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
add a comment |
Finally found a solution!
So problem was that I used DataContext dependancy, which was injected in the controller constructor - and it was disposed after HTTP request was completed.
So solution is to inject dependancy manually in the function itself, which needs access to the database:
Inject scope factory IServiceScopeFactory scopeFactory in the controller constructor.
Add this to my function where I need access to DBcontext:
using (var scope = _scopeFactory.CreateScope())
{
var context = scope.ServiceProvider.GetRequiredService();
...
}
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
Finally found a solution!
So problem was that I used DataContext dependancy, which was injected in the controller constructor - and it was disposed after HTTP request was completed.
So solution is to inject dependancy manually in the function itself, which needs access to the database:
Inject scope factory IServiceScopeFactory scopeFactory in the controller constructor.
Add this to my function where I need access to DBcontext:
using (var scope = _scopeFactory.CreateScope())
{
var context = scope.ServiceProvider.GetRequiredService();
...
}
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
edited Feb 5 at 9:41
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
answered Feb 4 at 9:33
Денис ПархоменкоДенис Пархоменко
113
113
add a comment |
add a comment |
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None of this code shows the actual problem, your repository (sigh) has closed the context
– Michael Randall
Jan 4 at 8:11
As written here, your method are not really "async". And your code is not usable as is. But yes, if they are called asynchronously and the _repo field is closed/disposed meanwhile, this is your error. My guess is you don't properly handle lifetime for your dbcontext.
– AFract
Jan 4 at 8:11
find which line causes error. and write on here to get answer from ppl.
– Arphile
Jan 4 at 8:12
Dig around in here
_repo.saveEventsToDB(events);work out why you have closed and disposed the context (somwhere else), this will be your answer– Michael Randall
Jan 4 at 8:17
Thing is, if I call _repo.saveEventsToDB(events) from another place of program, for example, like this: [HttpPost("saveone")] public async Task<IActionResult> saveOne(Event newEvent) { var events = new List<Event>(); events.Add(newEvent); await _repo.saveEventsToDB(events); return Ok(events); }' it works. So i think problem is because I call it from callback function.. Any idea what can I do?
– Денис Пархоменко
Jan 4 at 10:31