I'm trying to download a list of links of images to my server (Up to 40 links) using foreach.
In my case sometimes the link exists but I don't know why it's going to catch and cancel the download of the next link. Maybe it needs to wait for a little? because when I debug the app I see that the link was the application skipped and went to catch was available but sometimes it's open after few seconds in my browser so the response time from the server I trying to download sometimes need more time to load and open the link.
string newPath = "~/data/" + model.PostID + "/" + name + "/";
//test1 is a list of links
foreach (var item1 in test1)
{
HttpWebRequest request = WebRequest.Create(item1) as HttpWebRequest; request.Method = "HEAD";
try
{
using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
{
var webClient = new WebClient();
string path = newPath + i + ".jpg";
webClient.DownloadFileAsync(new Uri(item1), Server.MapPath(path));
string newlinks = "https://example.com/data/" + chapter.PostID + "/" + name + "/" + i + ".jpg";
allimages = allimages + newlinks + ',';
response.Close();
i++;
}
}
catch
{
break;
}
}
Now my main goal is to fix this issue but as I saw in debugging:
The Images Links I'm trying to download exists
Sometimes Need More Time to response
So How I can fix this ? when download cancel and a link exists, what I should do?
you can use this example:
class WebClientUtility : WebClient
{
public int Timeout { get; set; }
public WebClientUtility() : this(60000) { }
public WebClientUtility(int timeout)
{
this.Timeout = timeout;
}
protected override WebRequest GetWebRequest(Uri address)
{
var request = base.GetWebRequest(address);
if (request != null)
{
request.Timeout = Timeout;
}
return request;
}
}
//
public class DownloadHelper : IDisposable
{
private WebClientUtility _webClient;
private string _downloadUrl;
private string _savePath;
private int _retryCount;
public DownloadHelper(string downloadUrl, string savePath)
{
_savePath = savePath;
_downloadUrl = downloadUrl;
_webClient = new WebClientUtility();
_webClient.DownloadFileCompleted += ClientOnDownloadFileCompleted;
}
public void StartDownload()
{
_webClient.DownloadFileAsync(new Uri(_downloadUrl), _savePath);
}
private void ClientOnDownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
{
if (e.Error != null)
{
_retryCount++;
if (_retryCount < 3)
{
_webClient.DownloadFileAsync(new Uri(_downloadUrl), _savePath);
}
else
{
Console.WriteLine(e.Error.Message);
}
}
else
{
_retryCount = 0;
Console.WriteLine($"successfully download: # {_downloadUrl} to # {_savePath}");
}
}
public void Dispose()
{
_webClient.Dispose();
}
}
//
class Program
{
private static void Main(string[] args)
{
for (int i = 0; i < 100; i++)
{
var downloadUrl = $#"https://example.com/mag-{i}.pdf";
var savePath = $#"D:\DownloadFile\FileName{i}.pdf";
DownloadHelper downloadHelper = new DownloadHelper(downloadUrl, savePath);
downloadHelper.StartDownload();
}
Console.ReadLine();
}
}
to fix timeout problem you can create a derived class and set the timeout property of the base WebRequest class and
for retry you can use the DownloadFileCompleted event of the WebClient and implement your retry pattern there
You're using the async version of 'DownloadFileAsync'. However you're not awaiting the call, that leaves a mess with unpredicted behaviour.
Make your method async and then use this:
await webClient.DownloadFileAsync(new Uri(item1), Server.MapPath(path));
This Solved my case:
await Task.Run(() =>
{
webClient.DownloadFileAsync(new Uri(item1), Server.MapPath(path));
});
Related
This is a web site https://www.wsj.com/news/types/newsplus whose data is getting loaded by ajax at runtime. i have to read all article title text. from morning i tried lots of code but still no code worked because data is getting load by ajax.
This is my code which i tried.
HtmlDocument hd = GetHtmlAjax(new Uri("https://www.wsj.com/news/types/newsplus"), 300, true);
ParseData(hd);
HtmlElementCollection main_element = hd.GetElementsByTagName("h3");
if (main_element != null)
{
foreach (HtmlElement element in main_element)
{
string cls = element.GetAttribute("className");
if (String.IsNullOrEmpty(cls) || !cls.Equals("WSJTheme--headline--unZqjb45 undefined WSJTheme--heading-3--2z_phq5h typography--serif-display--ZXeuhS5E"))
continue;
HtmlElementCollection childDivs = element.Children.GetElementsByName("a");
foreach (HtmlElement childElement in childDivs)
{
//grab links and other stuff same way
string linktxt = childElement.InnerText;
}
}
}
WebBrowser wb = null;
public HtmlDocument GetHtmlAjax(Uri uri, int AjaxTimeLoadTimeOut,bool loadurl)
{
if (loadurl)
{
wb = new WebBrowser();
wb.ScriptErrorsSuppressed = true;
wb.Navigate(uri);
}
while (wb.ReadyState != WebBrowserReadyState.Complete)
Application.DoEvents();
Thread.Sleep(AjaxTimeLoadTimeOut);
Application.DoEvents();
return wb.Document;
}
i follow many links to handle this issue but fail. these are the links i followed.
htmlagilitypack and dynamic content issue
Get HTML in C# from page that Loads Dynamic Data
Retrieve ajax/JavaScript return results from webpage in c#
How to extract dynamic ajax content from a web page
please some tell me what to change in my code to parse title link text. thanks
Post code from #aepot
private static HttpClient client = new HttpClient();
private static async Task<T> GetJsonPageAsync<T>(string url)
{
using (HttpResponseMessage response = await client.GetAsync(url, HttpCompletionOption.ResponseHeadersRead))
{
response.EnsureSuccessStatusCode();
string text = await response.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<T>(text);
}
}
private async void button1_Click(object sender, EventArgs e)
{
try
{
dynamic newsList = await GetJsonPageAsync<dynamic>("https://www.wsj.com/news/types/newsplus?id={%22query%22:%22type:=\\%22NewsPlus\\%22%22,%22db%22:%22wsjie,blog,interactivemedia%22}&type=search_collection");
List<Task<dynamic>> tasks = new List<Task<dynamic>>();
foreach (dynamic item in newsList.collection)
{
string strUrl = "https://www.wsj.com/news/types/newsplus?id=" + item.id + "&type=article";
tasks.Add(GetJsonPageAsync<dynamic>(strUrl));
//tasks.Add(GetJsonPageAsync<dynamic>($"https://www.wsj.com/news/types/newsplus?id={item.id}&type=article"));
}
dynamic[] newsDataList = await Task.WhenAll(tasks);
foreach (dynamic newItem in newsDataList)
{
//Console.WriteLine(newItem.data.headline);
//Console.WriteLine(newItem.data.url);
txtData.Text += newItem.data.headline + System.Environment.NewLine;
txtData.Text += new string('-', 200); + System.Environment.NewLine;
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
AJAX is simple GET or POST request.
Using regular Browser dev tools I've found that page sends simple GET request and receive JSON data. JSON can be deserealized or explored via reader.
For JSON parsing i used Newtonsoft.Json NuGet package
Here's simple example based on WinForms app.
public partial class Form1 : Form
{
private static readonly HttpClient client = new HttpClient();
private async Task<T> GetJsonPageAsync<T>(string url)
{
using (HttpResponseMessage response = await client.GetAsync(url, HttpCompletionOption.ResponseHeadersRead))
{
response.EnsureSuccessStatusCode();
string text = await response.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<T>(text);
}
}
public Form1()
{
InitializeComponent();
ServicePointManager.DefaultConnectionLimit = 10; // to make it faster
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
}
private async void button1_Click(object sender, EventArgs e)
{
try
{
dynamic newsList = await GetJsonPageAsync<dynamic>("https://www.wsj.com/news/types/newsplus?id={%22query%22:%22type:=\\%22NewsPlus\\%22%22,%22db%22:%22wsjie,blog,interactivemedia%22}&type=search_collection");
List<Task<dynamic>> tasks = new List<Task<dynamic>>();
foreach (dynamic item in newsList.collection)
{
tasks.Add(GetJsonPageAsync<dynamic>($"https://www.wsj.com/news/types/newsplus?id={item.id}&type=article"));
}
dynamic[] newsDataList = await Task.WhenAll(tasks);
foreach (dynamic newItem in newsDataList)
{
textBox1.Text += newItem.data.headline + Environment.NewLine;
textBox1.Text += new string('-', 200) + Environment.NewLine;
}
}
catch (Exception ex)
{
textBox1.Text = ex.Message;
}
}
}
UPD: Added fix for .NET Framework 4.5.2
This question already has an answer here:
What would be a good way to Cancel long running IO/Network operation using Tasks?
(1 answer)
Closed 2 years ago.
I'm playing with TcpClient and when i use some Async operations they ignore the CancellationToken. After some reading, i know that it is intentionally and also knows that exists some ways to cancel awaits on Asyncs operations.
I just read next StackOverflow questions and articles that clarifies some points:
How to cancel a Task in await?
https://devblogs.microsoft.com/pfxteam/how-do-i-cancel-non-cancelable-async-operations/
Following previous articles, I could cancel NetworkStream.ReadAsync but that mechanisms doesn't work when i use them on NetworkStream.WriteAsync.
I have this code as minimal example:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
CancellationTokenSource ctSource;
private async void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
string http_resp = "";
var request_uri = new Uri("http://icanhazip.com");
//BIG FILE as postdata to test the WriteAsync (use one that you have on your disk)
string contents = File.ReadAllText(#"C:\Portables\4test.txt");
string post_data = contents;
ctSource = new CancellationTokenSource();
CancellationToken ct = ctSource.Token;
Task<string> task = HttpRequestAsync(post_data, request_uri, ct);
try
{
http_resp = await task;
}
catch
{
http_resp = "General error";
}
textBox1.Text = http_resp;
button1.Enabled = true;
}
private static async Task<string> HttpRequestAsync(string post_data, Uri request_uri, CancellationToken ct)
{
string result = string.Empty;
string http_method = "POST";
string post_content_type = "application/x-www-form-urlencoded";
var hostname = request_uri.Host;
var port = request_uri.Port;
var scheme = request_uri.Scheme;
using (TcpClient tcpClient = new TcpClient())
{
tcpClient.SendTimeout = 15;
tcpClient.ReceiveTimeout = 15;
try
{
await tcpClient.ConnectAsync(hostname, port);
}
catch (Exception d1)
{
if (ct.IsCancellationRequested)
{
result = "Cancelation requested on ConnectAsync";
}
else
{
result = d1.Message + "\r\n" + d1.GetType().FullName + d1.StackTrace; ;
}
return result;
}
//Build HTTP headers
string reqString = "";
string header_host = "Host: " + hostname + "\r\n";
string header_close = "Connection: Close\r\n";
string basic_headers = "User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:71.0) Gecko/20100101 Firefox/71.0\r\n";
basic_headers += "Referer: https://www.google.com\r\n";
string header_post = "";
if (http_method == "POST")
{
string header_content_type = "";
header_content_type = "Content-type: " + post_content_type + "\r\n";
int content_length = 0;
content_length = post_data.Length;
string header_content_length = "Content-length: " + content_length + "\r\n";
header_post = header_content_type + header_content_length;
}
reqString = http_method + " " + request_uri.PathAndQuery + " " + "HTTP/1.1" + "\r\n" + header_host + basic_headers + header_close + header_post + "\r\n";
if (http_method == "POST")
{
reqString += post_data;
}
var header_bytes = Encoding.ASCII.GetBytes(reqString.ToString());
//Starting the I/O Network operations
using (NetworkStream tcp_stream = tcpClient.GetStream())
{
try
{
//HERE is where i have problems cancelling this await while WriteAsync is working.
await tcp_stream.WriteAsync(header_bytes, 0, header_bytes.Length, ct).WithCancellation(ct);
//await tcp_stream.WriteAsync(header_bytes, 0, header_bytes.Length, ct);
}
catch (Exception d2)
{
if (ct.IsCancellationRequested)
{
result = "Cancelation requested on WriteAsync";
}
else
{
result = d2.Message + "\r\n" + d2.GetType().FullName + d2.StackTrace;
}
return result;
}
using (var memory = new MemoryStream())
{
try
{
await tcp_stream.CopyToAsync(memory, 81920, ct);
}
catch (Exception d3)
{
if (ct.IsCancellationRequested)
{
result = "Request cancelled by user (on read)";
}
else
{
result = d3.Message + "\r\n" + d3.GetType().FullName + d3.StackTrace;
}
return result;
}
memory.Position = 0;
byte[] data = memory.ToArray();
result = Encoding.UTF8.GetString(data);
}
}
}
return result;
}
private void button2_Click(object sender, EventArgs e)
{
ctSource.Cancel();
}
}
It works good when i use it on ReadAsync:
await tcp_stream.ReadAsync(response, 0, response.Length, ct).WithCancellation(ct);
It doesn't work when i use it on WriteAsync:
await tcp_stream.WriteAsync(header_bytes, 0, header_bytes.Length, ct).WithCancellation(ct);
No error is returned, simply the await isn't cancelled. To be more clear i added a minimal example as a Visual Studio 2015 project that you can download here: https://github.com/Zeokat/minimal_ex/archive/master.zip
It also includes a file 4test.rar that you can decompress into a file of 39MB 4test.txt. I use this text file as post_data contents for test because is big enougth to call the Cancel action while the WriteAsync is running.
Can someone give me a hand on this? I spend some days trying to fix this but couldn't achieve a proper solution.
Thanks in advance.
Dont use .WithCancellation(ct) use only await tcp_stream.WriteAsync(header_bytes, 0, header_bytes.Length, ct).
cts = new CancellationTokenSource();
pass ct = cts.Token
in cancel_event() :
if(cts != null) cts.Cancel();
I'm stuck with an App that is running on Windows 10 IoT Core. All Classes are working fine, except for the one that is creating a CSV File via JSON and is supposed to send it as an Email.
When the Code reaches the "ReturnToMainPage()" Function the Exception "System.Exception: The application called an interface that was marshalled for a different thread" is thrown.
The "funny" thing is, the Mail is being send and i recieve it but the Program won't switch to back to the Main Page as intendet after sending the Email.
Here is the Code of the Class:
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Text;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using EASendMail;
namespace PratschZahlstation
{
public sealed partial class MailChoice : Page
{
private TextBlock _headerText;
private ComboBox _mailComboBox;
private Button _execute;
private Button _abort;
private EnDecode _coder = EnDecode.get_EnDecodeSingleton();
private string _mailto = null;
public MailChoice()
{
this.InitializeComponent();
Init();
}
private void Init()
{
_headerText = HeaderText;
_mailComboBox = MailAdresses;
_mailComboBox.Items.Add("---");
_mailComboBox.Items.Add("dummy#mail.com");
_mailComboBox.SelectedIndex = 0;
_execute = DoFunction;
_abort = DoExit;
}
private void DoFunction_Click(object sender, RoutedEventArgs e)
{
string selectedMail = this._mailComboBox.SelectedItem.ToString();
if(selectedMail == "---")
{
_headerText.Text = "Bitte eine Emailadresse aus der Liste auswählen.";
}
else
{
_headerText.Text = "CSV wird erstellt und per Mail versendet!";
_execute.IsEnabled = false;
_abort.IsEnabled = false;
_mailComboBox.IsEnabled = false;
_mailto = selectedMail;
DateTime date = DateTime.Now;
string strippedDate = date.ToString("yyyy-MM-dd") + " 00:00:01";
GetDataForCSV(strippedDate);
}
}
private async void GetDataForCSV(string dateAsString)
{
string correctedDate = "2019-07-01 00:00:01";//dateAsString;
string date = _coder.Base64Encode(correctedDate);
HttpClient _client = new HttpClient();
Uri _uri = new Uri("URI TO JSON-API");
_client.BaseAddress = _uri;
var request = new HttpRequestMessage(HttpMethod.Post, _uri);
var keyValues = new List<KeyValuePair<string, string>>();
keyValues.Add(new KeyValuePair<string, string>("mode", "10"));
keyValues.Add(new KeyValuePair<string, string>("date", date));
request.Content = new FormUrlEncodedContent(keyValues);
var response = await _client.SendAsync(request);
string sContent = await response.Content.ReadAsStringAsync();
keyValues = null;
if (sContent != null)
{
byte[] bytes = Encoding.UTF8.GetBytes(sContent);
string json = Encoding.UTF8.GetString(bytes);
if (!json.Contains("success"))
{
List<CSV_SQL_Json_Object> _Json = JsonConvert.DeserializeObject<List<CSV_SQL_Json_Object>>(json);
response.Dispose();
request.Dispose();
_client.Dispose();
if (_Json.Count == 0)
{
}
else
{
CreateCSV(_Json);
}
}
else
{
List<JSON_Status> _Json = JsonConvert.DeserializeObject<List<JSON_Status>>(json);
_headerText.Text = "Es ist der Folgender Fehler aufgetreten - Errorcode: \"" + _coder.Base64Decode(_Json[0].success) + "\"\r\nFehlermeldung: \"" + _coder.Base64Decode(_Json[0].message) + "\"";
_Json.Clear();
response.Dispose();
request.Dispose();
_client.Dispose();
}
}
}
private async void CreateCSV(List<CSV_SQL_Json_Object> contentForCSV)
{
DateTime date = DateTime.Now;
string csvName = date.ToString("yyyy-MM-dd") + ".csv";
StorageFolder storageFolder = KnownFolders.MusicLibrary;
StorageFile csvFile = await storageFolder.CreateFileAsync(csvName, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false);
await FileIO.WriteTextAsync(csvFile, "Column1;Column2;Column3;Column4;\n");
foreach (var item in contentForCSV)
{
await FileIO.AppendTextAsync(csvFile, _coder.Base64Decode(item.Object1) + ";" + _coder.aesDecrypt(_coder.Base64Decode(item.Object2)) + ";" + _coder.aesDecrypt(_coder.Base64Decode(item.Object3)) + ";" + _coder.aesDecrypt(_coder.Base64Decode(item.Object4)) + "\n");
}
SendEmail(_mailto, csvName);
}
private async void SendEmail(string mailto, string csvName)
{
try
{
SmtpMail oMail = new SmtpMail("Mail");
SmtpClient oSmtp = new SmtpClient();
oMail.From = new MailAddress("noreply#dummy.com");
oMail.To.Add(new MailAddress(mailto));
oMail.Subject = "The Subject";
oMail.HtmlBody = "<font size=5>MailText</font>";
StorageFile file = await KnownFolders.MusicLibrary.GetFileAsync(csvName).AsTask().ConfigureAwait(false);
string attfile = file.Path;
Attachment oAttachment = await oMail.AddAttachmentAsync(attfile);
SmtpServer oServer = new SmtpServer("mail.dummy.com");
oServer.User = "dummyuser";
oServer.Password = "dummypass";
oServer.Port = 587;
oServer.ConnectType = SmtpConnectType.ConnectSSLAuto;
await oSmtp.SendMailAsync(oServer, oMail);
}
catch (Exception ex)
{
string error = ex.ToString();
_abort.IsEnabled = true;
}
ReturnToMainPage(); //This is where the Error Happens
}
private void ReturnToMainPage()
{
this.Frame.Navigate(typeof(MainPage));
}
private void DoExit_Click(object sender, RoutedEventArgs e)
{
this.Frame.Navigate(typeof(MainPage));
}
}
}
This could be an Threading issue. Navigation is only possible on the main-Thread.
You may want to try to marshal the call in:
Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
() =>
{
// Your UI update code goes here!
}
);
Source:
The application called an interface that was marshalled for a different thread - Windows Store App
Like Tobonaut said, you can use the Dispatcher.RunAsync to call the Navigation, it worked.
But your problem may not be this.
I copied your code and reproduced your problem and found that you have problems with the calls to read and write files:
// Your code
StorageFile csvFile = await storageFolder.CreateFileAsync(csvName, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false);
StorageFile file = await KnownFolders.MusicLibrary.GetFileAsync(csvName).AsTask().ConfigureAwait(false);
The Navigation will be work if you delete the .AsTask().ConfigureAwait(false).
Best regards.
I'm having problems creating a linkchecker, I'd like to have it online mainly for learning..
The problem is that i first had it as a console application which worked kinda well (i got broken urls to show i debug console), now that i'm trying to get it to web I'm having trouble..
How do I go about getting this into the document? I'm kinda stumped at the moment..
public partial class Default2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
public bool UrlIsValid(string url)
{
try
{
HttpWebRequest request = HttpWebRequest.Create(url) as HttpWebRequest;
request.Timeout = 5000; //set the timeout to 5 seconds to keep the user from waiting too long for the page to load
request.Method = "HEAD"; //Get only the header information -- no need to download any content
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
int statusCode = (int)response.StatusCode;
if (statusCode >= 100 && statusCode < 400) //Good requests
{
return true;
}
else if (statusCode >= 500 && statusCode <= 510) //Server Errors
{
string cl = (String.Format("The remote server has thrown an internal error. Url is not valid: {0}", url));
// Debug.WriteLine(cl, Convert.ToString(url));
return false;
}
}
catch (WebException ex)
{
if (ex.Status == WebExceptionStatus.ProtocolError) //400 errors
{
return false;
}
else
{
string cl = String.Format("Unhandled status [{0}] returned for url: {1}", ex.Status, url);
/// Debug.WriteLine(cl, Convert.ToString(ex));
}
}
catch (Exception ex)
{
object cl = String.Format("Could not test url {0}.", url);
Debug.WriteLine(cl, Convert.ToString(ex));
}
return false;
}
private void button1_Click(object sender, EventArgs e)
{
WebClient wc = new WebClient();
string checker = wc.DownloadString("http://administration.utbildningssidan.se/linkcheck.aspx");
while (checker.Contains("<a href="))
{
int checkstart = checker.IndexOf("<a href=") + 8;
int checkstop = checker.IndexOf(">", checkstart);
string validator = checker.Substring(checkstart, checkstop - checkstart);
// perform the check
if (!UrlIsValid(validator)) { Debug.WriteLine(validator); }
checker = checker.Substring(checkstop + 1);
}
}
}
Hope you understand what I want accomplished, having a hard time making sense right now..
I think you want Response.Write() in place of your Debug.WriteLine() methods. OR, you could create a TextArea object in your markup and use myTextArea.Text += "Some text";
I am programming an application for downloading articles from an SQL Database on the internet. I have programmed the Website for managing the articles. Now I'm downloading the article List in gzip Format and then I decompress them to a xml-File. When I'm done I want to insert the articles to the mobile phone. This works great. Now I want to add an progress Bar to see the state of the insertion. I tried with Threading but this doesn't work. I'm posting some pieces of code from my application and also the progressUpdate methods.
private void btn_send_Click(object sender, EventArgs e)
{
label1.Text = "Download started";
string ArticlesURL = "URLTOSITE";
InvokeAsync(ArticlesURL);
}
private void InvokeAsync(string URL)
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.AllowWriteStreamBuffering = true;
allDone.Reset();
request.BeginGetRequestStream(new AsyncCallback(ReadArticlesCallback), request);
allDone.WaitOne();
request.BeginGetResponse(new AsyncCallback(ResponseArticlesCallback), request);
}
private static void ReadArticlesCallback(IAsyncResult asynchronousResult)
{
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
//End the operation.
Stream postSream = request.EndGetRequestStream(asynchronousResult);
string postData = "articles=test";
//Convert the string into a byte array.
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
//Write to the request stream.
postSream.Write(byteArray, 0, postData.Length);
postSream.Close();
allDone.Set();
}
private static void ResponseArticlesCallback(IAsyncResult asynchronousResult)
{
Form1 f = new Form1();
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
HttpWebResponse resp = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
Stream streamResponse = resp.GetResponseStream();
StreamReader streamRead = new StreamReader(streamResponse);
string responseString = streamRead.ReadToEnd();
nbrArticles = Convert.ToInt16(responseString);
// Close the stream object.
streamResponse.Close();
streamRead.Close();
// Release the HttpWebResponse.
resp.Close();
f.truncate_articles();
f.get_articles();
}
private void get_articles()
{
string url = "URLTOSITE";
int startPoint = 0;
DownloadZipFile((object)startPoint, url);
DecompressFile();
getXmlAndInsertInDB();
}
private void getXmlAndInsertInDB()
{
int total = nbrArticles;
int count = total / 100; //How much articles are 1 percent
int i = 0;
String barcode = "";
String name = "";
bool state = false;
XmlTextReader reader = new XmlTextReader("Program Files\\SmartDeviceProject1\\articles.xml");
while (reader.Read())
{
switch (reader.NodeType)
{
case XmlNodeType.Element: //The node is an element
while (reader.MoveToNextAttribute()) //Get the attributes like barcode, lastname, firstname, pincode
switch (reader.Name)
{
case "barcode":
barcode = reader.Value.ToString();
state = false;
break;
case "name":
name = reader.Value.ToString();
state = true;
break;
}
break;
}
if (state == true)
{
cmd.CommandText = "INSERT INTO articles(barcode, name) " +
"VALUES('" + barcode + "','" + name + "');";
cmd.ExecuteNonQuery();
state = false;
i++;
if (i == count)
{
Thread t = new Thread(new ThreadStart(this.incrementProgressBar));
t.Start();
//incrementProgressBar();
i = 0;
}
}
}
reader.Close();
}
private void updateProgressBarMethod(int progress)
{
if (progressBar1.InvokeRequired)
{
//It was called from a non UI thread so we create a delegate
//and have the UI Thread call this method again
UpdateProgressBar = new UpdateProgressBarDelegate(updateProgressBarMethod);
this.Invoke(UpdateProgressBar, progress);
}
else
{
//Called from the UI Thread OK to update
//update your progress bar here
progressBar1.Value += progress;
}
}
private void incrementProgressBar()
{
//Call the method to update progress Bar on UI thread
//we do not need a delegate here that will be taken care of
//in the method
updateProgressBarMethod(1);
Application.DoEvents();
}
I think the problem is that I am using Callbacks. I have read that the Callbacks are also starting Threads. So I think the problem is there but I can't solve it.
I've found another very good site for threading with mobile applications: Updating the User Interface from a Worker Thread
Now with the new code, the debugger stops always at the same piece of code without any notification or exception :( Here is my new code:
if (i == count)
{
this.info_percent = "Synchro " + step.ToString() + "%";
this.Invoke(new EventHandler(WorkerUpdate)); //The Debugger stops here!
i = 0;
step++;
Thread.Sleep(700);
}
public void WorkerUpdate(object sender, EventArgs e)
{
this.lbl_percent.Text = this.info_percent;
this.lbl_percent.Update();
this.progressBar1.Value = step;
this.progressBar1.Update();
}
The Debugger stops at: this.Invoke(new EventHandler(WorkerUpdate));
I would suggest using the Background worker class. I had a similar problem and implemented the Background worker and it fixed my problem. Hopefully it will fix yours also
http://www.dotnetperls.com/backgroundworker
http://msdn.microsoft.com/en-us/library/cc221403(v=vs.95).aspx
I found another thread discussing this and thought it would help:
Is there a BackgroundWorker replacement for .NET Compact Framework 3.5?
Your code will always hang at this point:
if (i == count)
{
this.info_percent = "Synchro " + step.ToString() + "%";
this.Invoke(new EventHandler(WorkerUpdate)); //The Debugger stops here!
i = 0;
step++;
Thread.Sleep(700);
}
Make these changes:
public delegate void MethodInvoker(); // this is not defined in CF
if (i == count)
{
this.info_percent = "Synchro " + step.ToString() + "%";
object sender = null; // make this whatever you want/need
EventArgs e = new EventArgs();
if (this.InvokeRequired) {
MethodInvoker mi = delegate { WorkerUpdate(sender, e); } };
this.BeginInvoke(mi);
} else {
WorkerUpdate(sender, e);
}
i = 0;
step++;
// Thread.Sleep(700); Why is this here?
}
This should prevent those obnoxious freezes.