I have an trouble in C# program which using php scripts to translate words and download the result string into TextBox.
My program has two TextBoxes
txtWord, txtTranslatedWord
and that's the simplified code
WebClient c = new WebClient();
private void txtWord_TextChanged(object sender, EventArgs e)
{
string response = c.DownloadString("http://example.com/Services/Translator/lang/EnglishToArabic.php?Word=" + txtWord.Text);
switch (response.ToLower())
{
case "not exist":
{
txtTranslatedWord.Text = "{Sorry but no translation for this word!}";
break;
}
default:
{
txtTranslatedWord.Text = response;
break;
}
}
}
The problem its when the text is changed the program lagging and looks like it would Stopped Working.
The program worked successfully but after so much lagging ,
especially if the writer is writing so fast.
I tried BackgroundWorker and make an delay like when user stop writing for 2 second then program start to translate but still lagging without any luck.
Is there any easy way to do this without problems?
Try to use asynchrony.
WebClient does not support concurrent I/O operations, so will be use HttpClient.
HttpClient client = new HttpClient();
private async void txtWord_TextChanged(object sender, EventArgs e)
{
var response = await client.GetStringAsync(
"http://example.com/Services/Translator/lang/EnglishToArabic.php?Word=" + txtWord.Text);
switch (response.ToLower())
{
case "not exist":
{
txtTranslatedWord.Text = "{Sorry but no translation for this word!}";
break;
}
default:
{
txtTranslatedWord.Text = response;
break;
}
}
}
Your problem is that every character your user types into the textbox results in a WebClient download that has to complete before the next keypress can be accepted. I'd suggest you do the following...
Create a timer that starts or restarts each time the user enters a character and that when expires disables the textbox and runs the search before re-enabling the textbox. You'd also do well to use an asynchronous WebClient call.
Related
First of all hello guys i just wanted to add button that downloads zip files from link and then unzips and i ran into problems i get this error:
"System.IO.IOException: 'The process cannot access the file
'C:\GTA\TEST.zip' because it is being used by another process.'"
It looks really simple but i can't solve it so i hope you guys help me. this is code:
private void button2_Click(object sender, EventArgs e)
{
string root = #"C:\GTA";
//this if directory doesn't exist
if (!Directory.Exists(root))
{
Directory.CreateDirectory(root);
}
progressBar1.Value = 0;
WebClient webcl = new WebClient();
webcl.DownloadFileCompleted += Webcl_DownloadFileCompleted;
webcl.DownloadProgressChanged += Webcl_DownloadProgressChanged;
webcl.DownloadFileAsync(new Uri("https://download1474.mediafire.com/17r5hin4vceg/izkb8vk7pudg5g4/TEST.zip"), #"C:\GTA\TEST.zip");
string targetfolder = #"C:\GTA\UNZIPEDFolder";
string sourceZipFile = #"C:\GTA\TEST.zip";
ZipFile.ExtractToDirectory(sourceZipFile, targetfolder);
}
I'm no expert here, however you get the file asynchronosly without awaiting it.
DownloadFileAsync
So you make a call to extract the file while it's being downloaded.
You calling ExtractToDirectory before file will be actually downloaded, as file downloading is async. So, you need to await when downloading process will finish. To do so, you will need the following
make the whole event click handler async - private async void button2_Click(object sender, EventArgs e).
replace DownloadFileAsync which returns void and thus is not async/await-friendly with DownloadFileTaskAsync, which is awaitable.
Then you will able to await downloading with await webcl.DownloadFileTaskAsync(...args here...);
finally, you can remove DownloadFileCompleted subscription, as you may be sure that after await the file downloading is completed.
By the way, WebClient is considered as an old API and is not recommended for using in the new code. You may consider to switch to HttpClient.
To elaborate a bit on the two previous answers, you are in fact trying to unzip the file before you have downloaded it. You should change your code as follows:
private async void button2_Click(object sender, EventArgs e)
{
string root = #"C:\GTA";
//this if directory doesn't exist
if (!Directory.Exists(root))
{
Directory.CreateDirectory(root);
}
progressBar1.Value = 0;
WebClient webcl = new WebClient();
webcl.DownloadFileCompleted += Webcl_DownloadFileCompleted;
webcl.DownloadProgressChanged += Webcl_DownloadProgressChanged;
await webcl.DownloadFileAsync(new Uri("https://download1474.mediafire.com/17r5hin4vceg/izkb8vk7pudg5g4/TEST.zip"), #"C:\GTA\TEST.zip");
string targetfolder = #"C:\GTA\UNZIPEDFolder";
string sourceZipFile = #"C:\GTA\TEST.zip";
ZipFile.ExtractToDirectory(sourceZipFile, targetfolder);
}
Note the async as well as the await before DownloadFileAsync().
Additionally, you might want to refactor that a bit and move the download / unzip part out of the Button Event Handler.
Edit: Keeping the original question for continuity.
I then edited the question with replacement code for the ReadLine() method by using ReadExisting instead. It works however I still have the same freeze, where the app becomes unresponsive. Debug says it's locking (it takes a while to freeze, sometimes seconds, sometimes minutes) in the while () {} function where I wait for the complete message. More explanations below:
-- obsolete --
What is a good way to handle serialport.readtimeout exception?
try
{
serialPort1.Write(Command_);
if (!IsWriteComm_)
{
Response_ = serialPort1.ReadLine().Replace("\r", "");
}
}
catch (TimeoutException err)
{
DateTime d = DateTime.Now;
rtboxDiag.AppendText("\n" + d.ToString("HH:mm:ss") + ": ");
rtboxDiag.AppendText(err.Message);
if (!serialPort1.IsOpen)
InitConnection();
return Textbox_;
}
this bit of code is exectuted on a timer tick event.
I was having a weird "crash" of the app with an IO exception
"The I/O operation has been aborted because of either a thread exit or an application request."
no matter what I do I am not able to "recover" meaning, I am no longer able to poll data from the serial port.
I added this exception catch and it does log the exception. weirdly enough the test on !serialport.isopen is false (meaning the port is still open).
What might be a hint is: this error does STOP the timer somehow, this is not something I am doing in code. so I am suspecting something related to the timer, rather than the serialport, but I could be wrong.
Closing the port manually, and reconnecting does not fix the problem.
Disconnecting and reconnecting the USB does not fix the problem.
however, closing the app, and relaunching the app does fix the problem (without even disconnecting the MCU or power cycling the MCU/hardware).
-- /obsolete --
edit: the problem is appearing after a few seconds, sometimes minutes of flawless operations. I cannot repeat the issue using a serialport terminal polling the data the same way, at the same frequency. It seems the problem is not coming from the hardware itself.
cheers
Edit: I have yet to test the following modification, not sure if it will fix this problem (I doubt), but at least it's an attempt at not using .readline() which from what I've gathered is not good practice.
anyway here it is:
try
{
serialPort1.Write(Command_);
if (!IsWriteComm_)
{
while (!SerialRxCplt) ;
Response_ = SerialRxResponse.Replace("\r", "").Replace("\n", "");
SerialRxCplt = false;
//Response_ = serialPort1.ReadLine().Replace("\r", "");
}
}
catch (TimeoutException err)
{
DateTime d = DateTime.Now;
rtboxDiag.AppendText("\n" + d.ToString("HH:mm:ss") + ": ");
rtboxDiag.AppendText(err.Message);
if (!serialPort1.IsOpen)
InitConnection();
return Textbox_;
}
and I have the datareceived event enabled:
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
var serialPort = (System.IO.Ports.SerialPort)sender;
string dataReceived = serialPort.ReadExisting();
ProcessSerialData(dataReceived);
}
and this is how I am processing the data, and manually "waiting" for the \n character which tells me when the data has been fully received.
private void ProcessSerialData(string data)
{
SerialRxBuffer += data;
if (SerialRxBuffer.Contains("\n"))
{
SerialRxCplt = true;
SerialRxResponse = SerialRxBuffer;
SerialRxBuffer = "";
}
else
{
SerialRxCplt = false;
}
}
any input is welcome.
I have added "stuff" for debugging inside that while loop and it does work fine for a while and then freezes, no error or exception is thrown there. For some reason I have a feeling it's not related to the serial port.
I have even added this:
try
{
serialPort1.Write(Command_);
if (!IsWriteComm_)
{
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
while (!SerialRxCplt || Timer2StopWatchMilli > 5)
{
Timer2StopWatchMilli = stopWatch.Elapsed.TotalMilliseconds;
ExceptionMessage = Timer2StopWatchMilli.ToString();
IsException = true;
}
stopWatch.Stop();
if (!SerialRxCplt)
return Textbox_;
Response_ = SerialRxResponse.Replace("\r", "").Replace("\n", "");
SerialRxCplt = false;
//Response_ = serialPort1.ReadLine().Replace("\r", "");
}
}
the ExceptionMessage and IsException help me have an idea of what's happening in that loop. And in normal operations, it is what you would except, increments in the order of 0.0x milliseconds. Data is being processed correctly. When it freezes, nothing looks abnormal. I initially thought I was somehow getting "stuck" in an infinite loop but that || Timer2StopWatchMilli > 5 should get me out of it, acting as some sort of timeout.
one extra piece of info: when it freezes, the one CPU core is fully loaded. (I have a 6core CPU, and it's 16-17% in the task manager - memory usage is low < 30MB)
Any help is welcome
I fixed it by clearing RX/TX and stream buffers after each successful transaction.
I think data was being sent to the PC faster than it was able to read causing data to eventually accumulating on the Rx Buffer.
private void SerialPortClearBuffers()
{
serialPort1.DiscardOutBuffer();
serialPort1.DiscardInBuffer();
serialPort1.BaseStream.Flush();
}
I'm trying to figure out a bug in my C# Xamarin Android code. Simple thing this application is ought to do - connect to the REST API, download the contents as a string for further analysis. At first my mistake was not including async tasks and using voids instead, but when I changed them the code seems to be stuck at point of retrieval of data.
String content;
private void OnClick1(object sender, EventArgs e)
{
output.Text = "";
GetJSONTextFromWeb("https://ameobea.me/osutrack/api/get_changes.php?user=XXXXXX&mode=0", "XXXXXX", "0");
while (content==null)
{
DoNothing();
}
output.Text = content;
}
private async Task GetJSONTextFromWeb(String address, String user, String modeID)
{
URL url = new URL(address);
URLConnection conn = url.OpenConnection();
//conn.AddRequestProperty("user", user); those lines are
//conn.AddRequestProperty("mode", modeID); removed for investigation.
//conn.Connect(); //this one caused the same issue.
content = (String)conn.Content; //Here the code seems to freeze without any warning.
}
private void DoNothing()
{
//literally. Made to await for the result.
}
Anyone knows the possible reason?
I'd suggest swapping out the use of that particular library in favor of the System.Http assembly, it's supported in Xamarin and is a lot better documented. I'd change your above code to something like below (Don't forget to declare System.Net.Http in the same place that you've declared your other assemblies).
using System.Net.Http;
async private void OnClick1(object sender, EventArgs e)
{
output.Text = "";
// await the return of a string from the url address
// awaiting this removes the need for the pointless while loop you were doing
content = await GetJSONTextFromWeb("https://ameobea.me/osutrack/api/get_changes.php?user=XXXXXX&mode=0");
output.Text = content;
}
private async Task<string> GetJSONTextFromWeb(String address)
{
// The library you were using is a poorly documented port from a JAVA library
// I'd suggest using the http library, it's supported in Xamarin and has better docs
var client = new HttpClient();
var data = await client.GetStringAsync(address);
return data;
}
I am working on an ASP.NET Webform project (legacy code).On my button_click event i am sending sms message to all the datas populated in this.
var customerSMS = BusinessLayer.SMS.SmsSetup.GetAllCustomerSMS(OfficeId);
This takes around 15seconds to do all the computing and get the data(1000rows)
from the Db.And for each data it runs through the loop and does validation and
sends the sms and it does take time.I want to do this task in background and
redirect the user to the index page and the background process continues till it
gets out of the loop.I am new to this and still learning this beautiful
language C#.I did go through this amazing Asynchronous Programming async/await
and Multithreading approach and got hold of it only in simple WindowsForm
applications.Any reference/code snippet/best approach with a simple explanation for my case would be helpful.
My button click event code :
protected void ReturntoDashboard_Click(object sender, EventArgs e)
{
sms = Everest.Net.BusinessLayer.SMS.SmsSetup.GetSmsSetUp(OfficeId);
if (sms.EnableSmsData && sms.SmsCount > 0)
{
#region Loan Section
var smsLoan = Everest.Net.BusinessLayer.SMS.SmsSetup.GetLoanId(s.Sms_AccountNumber);
var loanId =
BusinessLayer.SMS.SmsSetup.GetLoanIdValue(s.Sms_AccountNumber);
var dateexceeded =
BusinessLayer.SMS.SmsSetup.IsDateExceeded(loanId);
if (smsLoan != null && dateexceeded == true)
{
foreach (Common.SMS.SMSSetup sm in smsLoan)
{
var smsClosingBalanceLoan = BusinessLayer.SMS.SmsSetup.GetAmountForLoanAlert( sm.LoanId,
BusinessLayer.Core.DateConversion
.GetCurrentServerDate()
.AddDays(sms.DaysbeforeLoanalerts).ToString());
if (smsClosingBalanceLoan != null)
{
if (smsClosingBalanceLoan.LoanAmountToPay > 0)
{
int smsSentAlertCount = sms.LoanAlertCount;
var logCount = BusinessLayer.SMS.SmsSetup.GetLoanSmsAlertSentCount(DateTime.Now.AddDays(-smsSentAlertCount).ToString("yyyy-MM-dd"), DateTime.Now.ToString("yyyy-MM-dd"), sm.LoanAccountNumber);
if (logCount < smsSentAlertCount)
{
smsLog = new Everest.Net.Common.SMS.SMSSetup();
finalMessage = "Dear Member, Your Loan accnt " + sm.LoanAccountNumber + " with Principal"+ "+" + "Int Amnt: Rs." + smsClosingBalanceLoan.LoanAmountToPay + " need to be payed.Thank You," + officeName.OfficeName;
smsLog.LogServiceType = "Loan";
smsLog.LogSmsType = s.Sms_SmsType;
smsLog.LogSmsMessage = finalMessage;
smsLog.LogCustomerId = s.CustomerId.ToString();
smsLog.LogAccountNumber = s.Sms_AccountNumber;
smsLog.LogAccountType = s.Sms_AccountType;
smsLog.LogSmsSentDate = BusinessLayer.Core.DateConversion.GetCurrentServerDate();
smsLog.LogSmsFailedDate = "";
smsLog.LogSentStatus = true;
smsLog.LogUserId = UserId;
smsLog.LogSmsFailedMessage = "";
try
{
var result = Everest.Net.BusinessLayer.SMS.smsParameters.SendSMS(sms.FromNum, sms.Token, sms.Url, cellNum, finalMessage);
}
catch (Exception ex)
{
smsLog.LogSmsFailedDate = System.DateTime.Now.ToString("MM/dd/yyyy HHmmss");
smsLog.LogSentStatus = false;
smsLog.LogSmsFailedMessage = ex.Message;
Everest.Net.BusinessLayer.SMS.SmsSetup.InsertSMSLog(smsLog);
}
sms = Everest.Net.BusinessLayer.SMS.SmsSetup.GetSmsSetUp(OfficeId);
sms.SmsCount = sms.SmsCount - 1;
Everest.Net.BusinessLayer.SMS.SmsSetup.UpdateSmsSetup(sms);
Everest.Net.BusinessLayer.SMS.SmsSetup.InsertSMSLog(smsLog);
}
}
}
}
}
}
}
}
catch (Exception ex)
The ideal solution would remove the responsibility of sending the SMS from the web application itself. Instead, the web application should create a database record containing the message and recipient addresses, and a separate background job (e.g. a Windows Service) should poll the database and send SMS messages when neeeded. This is the best solution in terms of fault tolerance and auditability, because there is a permanent record of the messaging job which can be resumed if the system fails.
That being said, maybe you don't want to go to all that trouble. If you feel strongly that you wish to send the SMS directly from the ASP.NET application, you will need to create a Task and queue it to run using QueueBackgroundWorkitem. You will need to refactor your code a bit.
Move all the logic for sending the SMS into a separate function that accepts all the information needed as parameters. For example,
static void SendSMS(string[] addresses, string messagetext)
{
//Put your SMS code here
}
When you need to call the function, queue it as a background item
HostingEnvironment.QueueBackgroundWorkItem(a => SendSMS(addresses, messageText));
If your worker task needs to access its own cancellation token (e.g. if it is supposed to loop until cancelled), it is passed as an argument to the lambda expression. So you could modify the prototype
static void SendSMS(string[] addresses, string messagetext, CancellationToken token)
{
while (!token.IsCancellationRequested)
{
//Put your code here
}
}
and pass it thus:
HostingEnvironment.QueueBackgroundWorkItem(token => SendSMS(addresses, messageText, token));
Placing the task in the background queue ensures that ASP.NET keeps track of the thread, doesn't try to garbage collect it, and shuts it down properly when the application pool needs to shut down.
After queuing the background operation, your page can render is content per usual and conclude the HTTP response while the task continues to execute.
hi there :) il get right to it.
Problem :
when i try to instanciate LiveConnectClient and then try to access the event : GetCompleted
which supose to be in the LiveConnectClient is not showing and on all the examples i been looking at even those on here are using it. this is not the only class this is happening on it is also happening on LiveAuthClient as well no events even the post on the net says there should be.
i tried to reinstall Vs2012 and sdk wp8 and live sdk from scratch but have not solved it
for refrence i using this example to see if i can it to work :
//event triggered when Skydrive sign in status is changed
private void btnSignIn_SessionChanged(object sender, Microsoft.Live.Controls.LiveConnectSessionChangedEventArgs e)
{
//if the user is signed in
if (e.Status == LiveConnectSessionStatus.Connected)
{
session = e.Session;
client = new LiveConnectClient(e.Session);
infoTextBlock.Text = "Accessing SkyDrive...";
//get the folders in their skydrive
client.GetCompleted +=
new EventHandler<LiveOperationCompletedEventArgs>(btnSignin_GetCompleted);
client.GetAsync("me/skydrive/files?filter=folders,albums");
}
//otherwise the user isn't signed in
else
{
infoTextBlock.Text = "Not signed in.";
client = null;
}
}
i got no luck solving it and running out of ideas. So im hoping one of u boys out there can shed some light on it or lend a hand with dew wise words :)
thanks in advance. and i do apologies if this is to long a post.
regards jens
Indeed, it seems like those events have been removed in the latest versions of the SDK. You don't need them though, thanks to the async/await keywords. First, mark your method as async, then call the GetAsync method with the await keyword. And place afterward the code you would normally put in the GetCompleted event:
private async void btnSignIn_SessionChanged(object sender, Microsoft.Live.Controls.LiveConnectSessionChangedEventArgs e)
{
//if the user is signed in
if (e.Status == LiveConnectSessionStatus.Connected)
{
session = e.Session;
client = new LiveConnectClient(e.Session);
infoTextBlock.Text = "Accessing SkyDrive...";
//get the folders in their skydrive
var result = await client.GetAsync("me/skydrive/files?filter=folders,albums");
// Do here what you would normally do in btnSignin_GetCompleted
}
//otherwise the user isn't signed in
else
{
infoTextBlock.Text = "Not signed in.";
client = null;
}
}