I'm working on a script wich is in a ASP.NET MVC5 application. This script is working on 15.000 files so i don't want to wait the end to refresh my view.
My problem is that i would like to refresh my view during my Async task.
I tried many solutions like using AJAX to reload my partial view during my task but when i launch my script, it block evrything and never refresh my view untill the end of this script.
My code :
View
#{
ViewBag.Title = "ConvertScript";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>ConvertScript</h2>
<div id="PartialDiv">
#{Html.Partial("getStatus");}
</div>
#section Scripts
{
#Scripts.Render("~/Scripts/jquery.unobtrusive-ajax.min.js")
<script type="text/javascript">
$(function () {
setInterval(function () { $('#PartialDiv').load('/Annotation/Refresh'); }, 1000); // every 3 sec
});
</script>
}
Controller
public string testOut(int callDuration, out int threadId)
{
var File = from m in db.Annotations where m.IsDocument == true select m;
int i;
for (i = 0; i < 100; ++i)
{
Annotation item = File.OrderBy(t => t.FileSize).Skip(i).Take(1).Single();
using (FileStream stream = new FileStream("C:\\Users\\administrator\\Documents\\Visual Studio 2013\\Projects\\Files\\" + item.FileName, FileMode.Create, FileAccess.ReadWrite))
{
byte[] fileContent = Convert.FromBase64String(item.DocumentBody);
Debug.Write("Doing item nb : " + i + " Filename : " + item.FileName + "\n");
stream.Write(fileContent, 0, fileContent.Length);
stream.Close();
Session["count_files"] = (int)Session["count_files"] + 1;
}
}
threadId = Thread.CurrentThread.ManagedThreadId;
return ("Yes");
}
public delegate string AsyncMethodCaller(int callDuration, out int threadId);
[OutputCache(NoStore = true, Location = OutputCacheLocation.Client, Duration = 1)]
public ActionResult Refresh()
{
Debug.Write("Refresh " + Session["State"] + "\n");
if ((int)Session["State"] == 2)
{
Debug.Write("In\n");
int threadId;
AsyncMethodCaller caller = testOut;
IAsyncResult result = caller.BeginInvoke(10, out threadId, null, null);
string res = caller.EndInvoke(out threadId, result);
}
Session["State"] = (int)Session["State"] + 1;
ViewData["count_file"] = (int)Session["count_files"];
return PartialView("getStatus");
}
Does anyone have an idea to do that ?
Thanks,
Oliver
You could use SignalR to send data to the client from the server in the async method. Basically, SignalR is an implementation by Microsoft of multiple methods (with fallbacks for almost every browser) to allow bi-directionnal communication, which is probably what you are looking for.
I suggest you learn it. You can read about it here : http://signalr.net/, and there is some content about SignalR on MVA. The documentation is here, and it seems to offer a lot of tutorials to get you started. Good luck with that.
Related
I have a progress bar logic that implements SignalR on a page that processes uploaded file. It works properly and produces correct progress.
However, it produces progress bar for ALL users, not just for the user that uploaded the file. In other words, one user uploads the file, but that progress for that file upload shows even on screens of other user/sessions that conducted no action on their ends
I did come up with a workaround, where I send a user id with the SignalR progress call/signal and compare it with the user id stored in a hidden field on aspx. If they don't match, I don't produce the progress bar. However, this fix seems to be like a dirty workaround.
Is there a more efficient way to ensure the SignalR to work only within one session?
Just in case here is my code
protected void btnSubmit_Click(object sender, EventArgs e)
{
HttpFileCollection attachments = null;
try
{
lblMessage.Text = string.Empty;
var hubContext = GlobalHost.ConnectionManager.GetHubContext<ProgressHub>();
hubContext.Clients.All.AddProgress("Upload has been initiated: ", string.Empty, "0",
Context.User.Identity.Name, pageName);
if (fileupload1.HasFile)
{
attachments = Request.Files;
if (attachments.Count > totalnumberoffiles)
{
lblMessage.Text += "Please select only " + totalnumberoffiles + " files.";
lblMessage.Visible = true;
}
else
{
double fileProgressPercentagePortion = 100 / attachments.Count;
double fileProgressPercentage = 0;
double fileProgressPercentageSegment = fileProgressPercentagePortion/6;
for (int i = 0; i < attachments.Count; i++)
{
HttpPostedFile attachment = attachments[i];
if (attachment.FileName == string.Empty)
{
continue;
}
hubContext.Clients.All.AddProgress("Currently processing: ", new System.IO.FileInfo(attachment.FileName).Name, "0",
Context.User.Identity.Name, pageName);
if (attachment.ContentLength > 0 && !String.IsNullOrEmpty(attachment.FileName))
{
hubContext.Clients.Client(hubContext.co).AddProgress("Currently processing: ", new System.IO.FileInfo(attachment.FileName).Name,
fileProgressPercentageSegment, Context.User.Identity.Name, pageName);
ProcessFile(attachment, hubContext, fileProgressPercentageSegment,
fileProgressPercentage);
fileProgressPercentage += fileProgressPercentagePortion;
}
}
}
}
}
catch (Exception e3)
{
}
finally
{
}
}
Here is my JavaScript
$(function () {
// Reference the auto-generated proxy for the hub.
var progress = $.connection.progressHub;
console.log(progress);
var hfUserAccount = document.getElementById("<%=hfUserAccount.ClientID %>");
// Create a function that the hub can call back to display messages.
progress.client.AddProgress = function (fileName, message, percentage, userAccount, pageName) {
if (userAccount === hfUserAccount.value && pageName === "CheckEFile.aspx") {
ProgressBarModal("show", fileName + " " + message);
document.getElementById("divProgress").style.display = "block";
document.getElementById("divUpload").style.display = "block";
document.getElementById("divProgress").style.width = percentage + "%";
document.getElementById("lblPercentage").innerHTML = parseInt(percentage) + "%";
$("#processingStatus").html("Please Wait. Checking files...");
$('#ProgressMessage').width(percentage);
if (percentage === "100%") {
ProgressBarModal();
}
}
};
$.connection.hub.start().done(function () {
var connectionId = $.connection.hub.id;
console.log(connectionId);
});
});
Here is my hub
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Microsoft.AspNet.SignalR;
namespace IAACCESS.SignalR
{
public class ProgressHub : Hub
{
static ProgressHub()
{
}
}
}
If you only want to respond to whoever called your server side method, you can use the Clients.Caller property like so:
// Notice 'Clients.Caller' not 'Clients.All'
hubContext.Clients.Caller.AddProgress("Currently processing: ", new System.IO.FileInfo(attachment.FileName).Name, "0", Context.User.Identity.Name, pageName);
Found a solution, in my aspx I have
$.connection.hub.start().done(function () {
var connectionId = $.connection.hub.id;
console.log(connectionId);
$('#<%=hfConnectionId.ClientID %>').val(connectionId);
});
where I set the connection ID to a hidden field
<asp:HiddenField id="hfConnectionId" runat="server" />
And in code-behind I now have
hubContext.Clients.Client(hfConnectionId.Value).AddProgress("Currently processing: ", fn4, currentProgress, Context.User.Identity.Name, pageName);
I have a string array which contains addresses of websites:
string[] arr = new string[]
{
"https://www/google.com",
"https://www.yahoo.com",
"https://www.microsoft.com"
};
I have to send these URLs as argument to the asynctask method so that I will be able to calculate the loading time of each website. I don't have to show the website pages, so I am not using webview.
I can use stopwatch or httprequest to calculate the loading time and my ultimate goal is that all the websites need to start loading at the same time asynchronously, and output has to look like the following
Loading time
google - 00:00:04:092345 (hr:min:sec:millisec) yahoo - 00:00:06:028458
How can I send an array to asynctask and how I can generate loading time without using await?
Here is a brief solution of what you could do.
This is not complete nor perfect. It will will give you the loading time of one URL. Also there is a suggestion of how you could extend this to multiple URLs.
You will need a WebView, either in code or from UI.
Load the URL into the WebView using webview.LoadUrl("https://www/google.com");.
Create a new class by extending it from WebViewClient as follows:
public class myWebViewClient : WebViewClient
{
public override void OnPageFinished(WebView view, string url)
{
base.OnPageFinished(view, url);
Console.WriteLine("OnPageFinished for url : " + url + " at : " + DateTime.Now);
}
}
In your OnCreate() method add the following line of code :
webview.SetWebViewClient(new myWebViewClient());
So from here what you have to do is, Create a Dictionary with URL as key and Loading time as value. Set all the loading time to 0 initially. Update the value corresponding to each URL in the OnPageFinished(). Create an async Task function which would return you the populated dictionary.
public async Task<Dictionary<string, double>> myAsyncFunction()
{
await Task.Delay(5); //to make it async
//Wait till all the OnPageFinished events have fired.
while (myDictionary.Any(x=>x.Value == 0) == true)
{
//there are still websites which have not fully loaded.
await Task.Delay(1); //wait a millisecond before checking again
}
return myDictionary;
}
You can call myAsyncFunction() in a seprate thread than your UI and implement the ContinueWith() or just let it run in a separate thread and write that output into somewhere that you can check when required.
eg : Task.Run(async () => await myAsyncFunction());
UPDATE : based on OP's comments
In the UI thread :
var myClassList = new List<myClass>
{
new myClass{URL = "https://www/google.com", TimeTaken = null},
new myClass{URL = "https://www.yahoo.com", TimeTaken = null},
new myClass{URL = "https://www.microsoft.com", TimeTaken = null}
};
Console.WriteLine("Started at : " + DateTime.Now.ToShortTimeString());
var business = new BusinessLogic();
var loadtimetask = business.GetLoadTimeTakenAsync(myClassList);
await loadtimetask;
Console.WriteLine("Completed at : " + DateTime.Now.ToShortTimeString());
And implementation class :
public async Task<List<myClass>> GetLoadTimeTakenAsync(List<myClass> myClassList)
{
Parallel.ForEach(myClassList, myClassObj =>
{
using (var client = new HttpClient())
{
myClassObj.StartTime = DateTime.Now;
var stream = client.GetStreamAsync(myClassObj.URL)
.ContinueWith((s) =>
{
if (s.IsCompleted)
{
var myClassObjCompleted = myClassList.Where(x => x.URL == myClassObj.URL).First();
myClassObjCompleted.EndTime = DateTime.Now;
myClassObjCompleted.TimeTaken = myClassObj.EndTime - myClassObj.StartTime;
}
});
Task.Run(async () => await stream);
}
});
while (myClassList.Any(x => x.TimeTaken == null))
{
await Task.Delay(1);
}
return myClassList;
}
//Create TextView to display status of Wifi
TextView wifitext = FindViewById<TextView>(Resource.Id.WifiTextView);
//Configuring Wifi connection
var connectivityManager = (ConnectivityManager)GetSystemService(ConnectivityService);
var activeConnection = connectivityManager.ActiveNetworkInfo;
if (activeConnection != null && activeConnection.IsConnected)
{
wifitext.Text = "WIFI AVAILABLE";
string[] urladdress = new string[] { "https://www.google.com/", "https://www.yahoo.com/"};
for (int i = 0; i < urladdress.Length; i++)
{
string url = urladdress[i];
//Call async method
Task returnedTask = Task_MethodAsync(url);
}
}
else
wifitext.Text = "WIFI UNAVAILABLE";
}
public async Task Task_MethodAsync(string url)
{
LinearLayout ll = FindViewById<LinearLayout>(Resource.Id.linearLayout1);
WebClient client = new WebClient();
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
Stream listurl = client.OpenRead(url);
StreamReader reader = new StreamReader(listurl);
stopwatch.Stop();
// listurl.Close();
var time = Convert.ToString(stopwatch.Elapsed);
I am using ASP.NET MVC 4 application, I need to Display messages in the Client, by sending messages from Controller to Client.
My requirement is user click a button in UI and i will process the files on the server and Display message in UI on end of each foreach file i process. i need to show the File names in the Client Using ASP.NET MVC.
Can any one Help how to show the messages in the Client by calling client method from server on for-each loop each time.
I am able to call the controller and end of each controller I am sending final message to UI, but how to send on each foreach loop iteration?
Try this:
Script method to update progress based on predefined interval you want
Controller:
public class HomeController : Controller
{
private static IDictionary<Guid, int> tasks = new Dictionary<Guid, int>();
public ActionResult Index()
{
return View();
}
public ActionResult Start()
{
var taskId = Guid.NewGuid();
tasks.Add(taskId, 0);
Task.Factory.StartNew(() =>
{
for (var i = 0; i <= 100; i++)
{
tasks[taskId] = i; // update task progress
Thread.Sleep(50); // simulate long running operation
}
tasks.Remove(taskId);
});
return Json(taskId);
}
public ActionResult Progress(Guid id)
{
return Json(tasks.Keys.Contains(id) ? tasks[id] : 100);
}
}
View:
<script type="text/javascript">
function updateMonitor(taskId, status) {
$("#" + taskId).html("Task [" + taskId + "]: " + status);
}
$(function () {
$("#start").click(function (e) {
e.preventDefault();
$.post("Home/Start", {}, function (taskId) {
// Init monitors
$("#monitors").append($("<p id='" + taskId + "'/>"));
updateMonitor(taskId, "Started");
// Periodically update monitors
var intervalId = setInterval(function () {
$.post("Home/Progress", { id: taskId }, function (progress) {
if (progress >= 100) {
updateMonitor(taskId, "Completed");
clearInterval(intervalId);
} else {
updateMonitor(taskId, progress + "%");
}
});
}, 100);
});
});
});
Start new task …
You have to write an ActionResult that progressively write result to the response. so you can show the user some data in every foreach loop iteration. I have written a simple ActionResult that writes a number every 2 seconds:
public class ProgressiveResult : ActionResult
{
public override void ExecuteResult(ControllerContext context)
{
for (int i = 0; i < 20; i++)
{
context.HttpContext.Response.Write(i.ToString());
Thread.Sleep(2000);
context.HttpContext.Response.Flush();
}
context.HttpContext.Response.End();
}
}
and this is an action that returns this result:
public ActionResult LongProcess()
{
return new ProgressiveResult();
}
So you can write an ActionResult and write your foreach code in ExecuteResult method.
UPDATE:
You can make this call with an Ajax request and return result with a simple code like the following code:
var result = "";
function showResult() {
if (result !== oReq.responseText) {
result = oReq.responseText;
console.log(result);
}
}
var oReq = new XMLHttpRequest();
oReq.open("get", "/Home/LongProcess", true);
oReq.send();
setInterval(showResult, 1000);
I have written a class which gets the post data using jquerypost and then perform some crud operations. Its works fine adding stuff to the database , but it doesnt redirects to the page when passing certain data , below is the code :
$('#clickme').click(function (e) {
e.preventDefault();
indx = $("#DropDownList1 option:selected").index();
indx += 1;
var test = $("#DropDownList" + (indx + 1));
var url = "/Base/performOperations/shootme/"
jQuery.post(url, { name: jQuery("#name").val(), email: jQuery("#email").val(), federation: jQuery(test).val(), selectedscheme: jQuery("#DropDownList1").val() },
function (data) {
if (data == scheme1) {
window.location = "http://www.openme.com"
}
});
});
namespace pw
{
public class performOperations
{
public static string ShootMe() {
HttpRequest post = HttpContext.Current.Request;
string name = post["name"];
string email = post["email"];
string selectedscheme = post["selectedscheme"];
string federation = post["federation"];
string conn = System.Configuration.ConfigurationManager.AppSettings["mydb"];
string sql = "INSERT INTO dbo.mydb(Email,Name,schemes,LoginDate,schemeType) VALUES(#email,#name,#scheme,#dateTime,#federation)";
SqlHelper.ExecuteNonQuery(conn, CommandType.Text, sql,
new SqlParameter("#email", email),
new SqlParameter("#name", name),
new SqlParameter("#scheme", selectedscheme),
new SqlParameter("#dateTime", DateTime.Now),
new SqlParameter("#federation", federation));
return selectedscheme;
}
}
}
Any ideas why the redirect doesnt takes place, or am i doing it in a wrong way , i need to redirect to a particular page once the data is injected to the db.
Any assistance will be appreciated
If you are calling the POST method using AJAX, redirection at server side will not work.
You will have to redirect it at client side after request completion using javascript the request.
$('#clickme').click(function (e) {
e.preventDefault();
indx = $("#DropDownList1 option:selected").index();
indx += 1;
var test = $("#DropDownList" + (indx + 1));
var url = "/Base/sample/Hello/"
jQuery.post(url, { name: jQuery("#name").val(), email: jQuery("#email").val(), federation: jQuery(test).val(), selectedscheme: jQuery("#DropDownList1").val() },
function (data) {
if (data == "shoothim") {
window.location = "http://www.cuthishead.com"
}
else if(data == "shoother")
{
window.location = "http://www.chopherbody.com"
}
else if(data == "shootboth")
{
window.location = "http://www.fulldeath.tv"
}
});
return selectedscheme or URL from your page method
set window.location based on web method result on jquery
need to set WebMethod attribute for your C# method
Check Using jQuery to Call ASP.NET AJAX Page Methods – By Example
I have a thread that returns a site's http response status, but sometimes my program returns false results. and after a while it gives good results.
False result:
it takes a big a mount of time to check, and then it says that (for example) Google is down, which is quite not reasonable, but after a few seconds it returns good results
Can you take a look and tell me whats wrong? or how I can I improve it?
Checks all sites in datagrid:
private void CheckSites()
{
if (CheckSelected())
{
int rowCount = dataGrid.BindingContext[dataGrid.DataSource, dataGrid.DataMember].Count;
string url;
for (int i = 0; i < rowCount; i++)
{
url = dataGrid.Rows[i].Cells[2].Value.ToString();
if (url != null)
{
Task<string[]> task = Task.Factory.StartNew<string[]>
(() => checkSite(url));
// We can do other work here and it will execute in parallel:
//Loading...
// When we need the task's return value, we query its Result property:
// If it's still executing, the current thread will now block (wait)
// until the task finishes:
string[] result = task.Result;
selectRows();
if (result[0] != System.Net.HttpStatusCode.OK.ToString() && result[0] != System.Net.HttpStatusCode.Found.ToString() && result[0] != System.Net.HttpStatusCode.MovedPermanently.ToString())
{
//bad
notifyIcon1.ShowBalloonTip(5000, "Site Down", dataGrid.Rows[i].Cells[2].Value.ToString() + ", has a status code of:" + result, ToolTipIcon.Error);
dataGrid.Rows[i].DefaultCellStyle.BackColor = System.Drawing.Color.Wheat;
TimeSpan ts;
TimeSpan timeTaken = TimeSpan.Parse(result[1]);
dataGrid.Rows[i].Cells[3].Value = result[0];
dataGrid.Rows[i].Cells[3].Style.BackColor = System.Drawing.Color.Red;
dataGrid.Rows[i].Cells[4].Value = timeTaken.Seconds.ToString() + "." + String.Format("{0:0.00000}", timeTaken.Milliseconds.ToString()) + " seconds.";
string sec = (DateTime.Now.Second < 10) ? "0" + DateTime.Now.Second.ToString() : DateTime.Now.Second.ToString();
string min = (DateTime.Now.Minute < 10) ? "0" + DateTime.Now.Minute.ToString() : DateTime.Now.Minute.ToString();
string hour = (DateTime.Now.Hour < 10) ? "0" + DateTime.Now.Hour.ToString() : DateTime.Now.Hour.ToString();
dataGrid.Rows[i].Cells[5].Value = hour + ":" + min + ":" + sec;
//loadbar
}
else if (result[0] == "catch")//catch
{
notifyIcon1.ShowBalloonTip(10000, "SITE DOWN", dataGrid.Rows[i].Cells[1].Value.ToString() + ", Error:" +result[1], ToolTipIcon.Error);
dataGrid.Rows[i].Cells[3].Value = result[1];
dataGrid.Rows[i].Cells[3].Style.BackColor = System.Drawing.Color.Red;
//loadbar
}
else
{
//good
TimeSpan timeTaken = TimeSpan.Parse(result[1]);
dataGrid.Rows[i].Cells[3].Value = result[0];
dataGrid.Rows[i].Cells[3].Style.BackColor = System.Drawing.Color.LightGreen;
dataGrid.Rows[i].Cells[4].Value = timeTaken.Seconds.ToString() + "." + String.Format("{0:0.00000}", timeTaken.Milliseconds.ToString()) + " seconds.";
string sec = (DateTime.Now.Second < 10) ? "0" + DateTime.Now.Second.ToString() : DateTime.Now.Second.ToString();
string min = (DateTime.Now.Minute < 10) ? "0" + DateTime.Now.Minute.ToString() : DateTime.Now.Minute.ToString();
string hour = (DateTime.Now.Hour < 10) ? "0" + DateTime.Now.Hour.ToString() : DateTime.Now.Hour.ToString();
dataGrid.Rows[i].Cells[5].Value = hour + ":" + min + ":" + sec;
//loadbar
}
selectRows();
}
}
}
}
Checks a site:
/////////////////////////////////
////Check datagrid websites-button - returns response
/////////////////////////////////
private string[] checkSite(string url)
{
string[] response = new string[2];
url = dataGrid.Rows[0].Cells[2].Value.ToString();
if (url != null)
{
try
{
HttpWebRequest httpReq;
httpReq.Timeout = 10000;
//loadbar
dataGrid.Rows[0].DefaultCellStyle.BackColor = System.Drawing.Color.Wheat;
System.Diagnostics.Stopwatch timer = new System.Diagnostics.Stopwatch();
timer.Start();
HttpWebResponse httpRes = (HttpWebResponse)httpReq.GetResponse(); //httpRes.Close();
timer.Stop();
//loadbar
HttpStatusCode httpStatus = httpRes.StatusCode;
response[0] = httpStatus.ToString();
response[1] = timer.Elapsed.ToString();//*
httpRes.Close();
return response;
}
catch (Exception he)
{
response[0] = "catch";
response[1] = he.Message;
return response;
}
}
response[0] = "catch";
response[1] = "No URL entered";
return response;
//dataGrid.Rows[i].DefaultCellStyle.BackColor = System.Drawing.Color.Blue;
}
Thanks in advance.
Assuming the code provided is the actual code used:
First of all, your definition of 'False result' and 'Good result' is wrong. If you expect A but get B, that doesn't mean B is invalid. If your wife is giving birth and you expect a boy but it turns out the be a girl, its not a false result. Just unexpected.
That said: lets analyze your work: If it takes a long long time to check a site only to finally get a ??? result which isn't a 200 response code. We can almost savely assume you are dealing with a timeout. If your router, google or any fundamental network device in between is having problems, its expected to get an unexpected answer. "Timeout", "Bad Request", "Server not available" etc. Why would this happen? Its impossible to say for certain without having direct access to your environment.
Looking at your code however, i see that you're using the default TaskScheduler for making each check run as a task in the background (assuming you havent changed the default task scheduler which would be a vey bad practice to begin with). The default task scheduler, schedules each task on the threadpool which results in many many tasks running simultanious. Here we have a good candidate for overloading your network. Many sites (esspecially google) are kinda sensitive for handling many requests from the same source (esspecially if the frequency is high) so maybe google is blocking you temporarily or holding you back. Again, at this point it's pure speculation but the fact that you're running all checks simultaniously (unless the thread pool is on his max) is very likely the cause of your problem.
UPDATE
I would recommend working with a LimitedConcurrencyTaskScheduler ( see here: http://blogs.msdn.com/b/pfxteam/archive/2010/04/09/9990424.aspx ). Here you can limit the amount of tasks that can be run asynchronously. You have to do some testing for what number works ideally in your situation. Also make sure that the frequency is not 'too' high. Its hard to define what is too high, only testing can proof that.
In order to simulate your scenario, I have created a Winform with data grid and a button. On load of the form, I programmatically creates list of url’s (in a table) and bind to data grid. And on button click, we start the download process. In concise, the you have to write more defensive code and the following code only a skeleton of how you can fix the issue.
using System;
using System.Data;
using System.Net;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace app
{
public partial class Form1 : Form
{
DataTable urls = new DataTable();
public Form1()
{
InitializeComponent();
}
//Fill your uri's and bind to a data grid.
void InitTable()
{
//Silly logic to simulate your scenario.
urls = new DataTable();
urls.Columns.Add(new DataColumn("Srl", typeof(string)));
urls.Columns.Add(new DataColumn("Urls", typeof(Uri)));
urls.Columns.Add(new DataColumn("Result", typeof(string)));
DataRow dr = urls.NewRow();
dr["Srl"] = "1";
dr["Urls"] = new Uri("http://www.microsoft.com");
dr["Result"] = string.Empty;
urls.Rows.Add(dr);
dr = urls.NewRow();
dr["Srl"] = "2";
dr["Urls"] = new Uri("http://www.google.com");
dr["Result"] = string.Empty;
urls.Rows.Add(dr);
dr = urls.NewRow();
dr["Srl"] = "3";
dr["Urls"] = new Uri("http://www.stackoverflow.com");
dr["Result"] = string.Empty;
urls.Rows.Add(dr);
urls.AcceptChanges();
}
void UpdateResult()
{
dataGridView1.DataSource = urls;
}
//Important
// This example will freeze UI. You can avoid this while implementing
//background worker or pool with some event synchronization. I haven't covered those area since
//we are addressing different issue. Let me know if you would like to address UI freeze
//issue. Or can do it your self.
private void button1_Click(object sender, EventArgs e)
{
//Create array for Task to parallelize multiple download.
var tasks = new Task<string[]>[urls.Rows.Count];
//Initialize those task based on number of Uri's
for(int i=0;i<urls.Rows.Count;i++)
{
int index = i;//Do not change this. This is to avoid data race
//Assign responsibility and start task.
tasks[index] = new Task<string[]>(
() => checkSite(
new TaskInput(urls.Rows[index]["Urls"].ToString(), urls.Rows[index]["Srl"].ToString())));
tasks[index].Start();
}
//Wait for all task to complete. Check other overloaded if interested.
Task.WaitAll(tasks);
//block shows how to access result from task
foreach (var item in tasks)
{
DataRow[] rows=urls.Select("Srl='"+item.Result[2]+"'");
foreach (var row in rows)
row["Result"]=item.Result[0]+"|"+item.Result[1];
}
UpdateResult();
}
//This is dummy method which in your case 'Check Site'. You can have your own
string[] checkSite(TaskInput input)
{
string[] response = new string[3];
if (input != null)
{
try
{
WebResponse wResponse = WebRequest.Create(input.Url).GetResponse();
response[0] = wResponse.ContentLength.ToString();
response[1] = wResponse.ContentType;
response[2] = input.Srl;
return response;
}
catch (Exception he)
{
response[0] = "catch";
response[1] = he.Message;
response[2] = input.Srl;
return response;
}
}
response[0] = "catch";
response[1] = "No URL entered";
response[2] = input.Srl;
return response;
}
private void Form1_Load(object sender, EventArgs e)
{
InitTable();
UpdateResult();
}
}
//Supply custom object for simplicity
public class TaskInput
{
public TaskInput(){}
public TaskInput(string url, string srl)
{
Url = url;
Srl = srl;
}
public string Srl { get; set; }
public string Url { get; set; }
}
}