I thought this might be simple but i guess it's not, i have like 100 websites i need to load into a browser. I've loaded them into a List but my foreach happens before the website loads. Does anybody have a way to make each of these load and actually process WebBrowserDocumentComplete before loading the next one? queue doesn't work.
foreach(string oneWebsite in ALLWebSites)
{
webBrowser1.Navigate(oneWebsite);
webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser1_DocumentCompleted);
}
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
//do work
}
An AutoResetEvent should work
http://msdn.microsoft.com/en-us/library/system.threading.waithandle.waitone(v=vs.71).aspx
static AutoResetEvent autoEvent = new AutoResetEvent(false);
webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser1_DocumentCompleted);
foreach(string oneWebsite in ALLWebSites)
{
webBrowser1.Navigate(oneWebsite);
autoEvent.WaitOne(new TimeSpan(0, 1, 0), false))
}
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
//do work
autoEvent.Set();
}
At the end of the DocumentCOmplete handler have the browser navigate to the next site in the list.
Something like this should work:
var websiteIndex = 0;
webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser1_DocumentCompleted);
private void ProcessWebsite()
{
if (websiteIndex < ALLWebSites.Count)
{
webBrowser1.Navigate(ALLWebSites[websiteIndex]);
websiteIndex++;
}
}
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
//do work
// when work is done, process next one
ProcessWebsite();
}
Related
i am working on project in C# and its contain a methods that need a long time to be executed so i need a progress bar that tell the user about how much remain and i don't know how .
i google for it and i see courses about BackgroundWorker and still don't know how to use it
private void Lock_Methods()
{
foreach (FolderInfo fi in FolderInfo)
{
// code need a lot of time ....
}
}
any help please ...
Declare
var bw = new BackgroundWorker()
{ WorkerReportsProgress = true };
bw.RunWorkerAsync();
bw.DoWork += bw_DoWork;
bw.ProgressChanged += bw_ProgressChanged;
And
private void bw_DoWork(object sender, DoWorkEventArgs e)
{
for(int i = 0: i < FolderInfo.Count; i++)
{
//...
(sender as BackgroundWorker).ReportProgress((int)(100/FolderInfo.Count)*i, null);
}
}
private void bw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
I'm trying to make a label refresh every second so the countdown updates, having some trouble. I'm extremely new to C# apologies for the noob questions.
private void Form1_Load(object sender, EventArgs e)
{
bool ephCD = true;
int ephHours = (DateTime.Today.AddDays(1) - DateTime.Now).Hours;
int ephMinu = (DateTime.Today.AddDays(1) - DateTime.Now).Minutes;
int ephSecs = (DateTime.Today.AddDays(1) - DateTime.Now).Seconds;
label1.Text = ephHours.ToString() + ":" + ephMinu.ToString() + ":" + ephSecs.ToString();
while (ephCD == true)
{
label1.Refresh();
}
}
When launching this the program doesn't even appear.
Why does the program not appear?
You are performing an infinite loop in Form_Load. This means that the form will never finish loading, and your program will be stuck.
Your refresh loop needs to be on a separate thread, or ideally toss the loop and use a Timer instead of spin locking the CPU on an infinite loop.
Timer myTimer = new Timer(1000);
void Form1_Load()
{
myTimer.Elapsed += UpdateLabel;
myTimer.Start();
}
private void UpdateLabel(object sender, ElapsedEventArgs e)
{
//Update label here
}
Updating the label in a while statement is not a good option, a better approach would be to use Timer class
var aTimer = new System.Timers.Timer(1000);
aTimer.Elapsed += OnTimedEvent;
aTimer.Enabled = true;
private static void OnTimedEvent(Object source, ElapsedEventArgs e)
{
//update the label
}
This will do, just copy and paste:
private void Form1_Load(object sender, EventArgs e)
{
// To update the first time.
label1.Text = (DateTime.Today.AddDays(1)- DateTime.Now).ToString(#"hh\:mm\:ss");
var timer = new Timer {Interval = 1000};
timer.Tick += (o, args) =>
{
label1.Text = (DateTime.Today.AddDays(1)- DateTime.Now).ToString(#"hh\:mm\:ss");
};
timer.Start();
}
I ended up with this simpler solution:
<script>
var myTimer = setInterval(Atualizar, 20000);
function Atualizar() {
__doPostBack('UpdatePanelNew', '');
}
</script>
Make sure you wrap what you want to update within an UpdatePanel.
This code will request a postback in every 20s. So in the code behind I can do this:
protected void Page_Load(object sender, EventArgs e)
{
myLabel.InnerText = GetInDatabaseTheValueIwant();
}
I want to know how to show image loading progress in progress-bar in win form.
my code is
private void Form2_Load(object sender, EventArgs e)//load form and get profile and avatar
{
backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
backgroundWorker1.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted);
backgroundWorker1.RunWorkerAsync();
}
private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
label2.Text = "Avatar Loaded";
}
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)//showing progress
{
if (InvokeRequired)
{
BeginInvoke(new Action(() => backgroundWorker1_ProgressChanged(sender, e)));
}
else
{
if (progressBarX1.Value != e.ProgressPercentage)
{
progressBarX1.Value = e.ProgressPercentage;
progressBarX1.Refresh();
}
}
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)//loading avatar
{
WebClient wc = new WebClient();
Stream stream = wc.OpenRead("http://avatar.nimbuzz.com/getAvatar?jid=" + textBox1.Text);
pictureBox1.Image = (Image.FromStream(stream));
}
The image loads successfully but do not show any progress in progress-bar
Well, i would use the ProgressChanged Event from a WebClient to get the result of how far the download progress actually is. Then you can't save it from the thread of the backgroundworker, so you gotta do this when you have the file.
UPDATED
private BackgroundWorker bgw;
private void Form1_Load(object sender, EventArgs e)
{
bgw = new BackgroundWorker();
bgw.DoWork += bgw_DoWork;
bgw.WorkerReportsProgress = true;
bgw.RunWorkerCompleted += bgw_RunWorkerCompleted;
bgw.ProgressChanged += bgw_ProgressChanged;
bgw.RunWorkerAsync();
}
void bgw_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
}
void bgw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
pictureBox1.Image = (Image)e.Result;
}
void bgw_DoWork(object sender, DoWorkEventArgs e)
{
WebClient wc = new WebClient();
wc.DownloadProgressChanged += wc_DownloadProgressChanged;
Stream stream = wc.OpenRead("" + textBox1.Text);
e.Result = (Image.FromStream(stream));
}
void wc_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
bgw.ReportProgress(e.ProgressPercentage);
}
The problem with your code is that backgroundWorker1_ProgressChanged() is called in the context of the worker thread but UI updates can only be done within the UI thread (main thread). In your scenario you must call:
progressBarX1.Value = e.ProgressPercentage;
within the UI thread. There are many ways how to do this but a simple one is to use InvokeReqzired() to check if you are in the UI thread and you are not then call BeginInvoke() to send the execution of that command to the UI-/main-thread. The following should do the trick:
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
if (InvokeRequired)
{
BeginInvoke(new Action(() => backgroundWorker1_ProgressChanged(sender, e)));
}
else
{
progressBarX1.Value = e.ProgressPercentage;
}
}
Update:
I would also change:
backgroundWorker1.RunWorkerAsync();
backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
to:
backgroundWorker1.ProgressChanged += new ProgressChangedEventHandler(backgroundWorker1_ProgressChanged);
backgroundWorker1.RunWorkerAsync();
so the progress event is assigned (and therefore in place) before starting the asynchronous work. Otherwise you may miss a progress call.
Update 2:
You also need the following line to execute in the UI thread:
pictureBox1.Image = (Image.FromStream(stream));
To do so use the Completed event of BackgroundWorker and bass the image data using the result parameter. Then in the eventhandler use InvokeRequired() and BeginInvoke() just like in the Progress event).
Uodate 3:
Remeins unchanged is good as you don't get a crash because of not calling UI stuff in the UI thread ;-)
Try to force a repaint on the control by calling:
progressBarX1.Refresh();
(just after you assigned a new value to it).
So the code in the progress event looks like this:
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
if (InvokeRequired)
{
BeginInvoke(new Action(() => backgroundWorker1_ProgressChanged(sender, e)));
}
else
{
if (progressBarX1.Value != e.ProgressPercentage)
{
progressBarX1.Value = e.ProgressPercentage;
progressBarX1.Refresh();
}
}
}
If that still doesn't work check that your main/UI thread is not blocked or totally busy.
Update 4:
Just to make sure: you need to enable progress-reporting on the background worker and call its ReportProgress() method from time to time within the backgroundWorker1_DoWork(). See the following MS-Tutorial for more information on usage of the BackgroundWorker: http://msdn.microsoft.com/en-us/library/cc221403(v=vs.95).aspx
Enabling progress reporting on a backgroundworker:
backgroundWorker1.WorkerReportsProgress = true;
or use the form-designer and set the property WorkerReportsProgress to True. Then you still need to call the backgroundWorker1.ReportProgress() from time to time.
Update 5:
Ok, lets give it a complete try. I've checked some reference docs from MS so in case of the backgroundworker ProgressChanged and Completed events you don't need to BeginInvoke() them as MS does this already for you.
private void Form2_Load(object sender, EventArgs e)
{
getto();
backgroundWorker1.WorkerReportsProgress = true;
backgroundWorker1.ProgressChanged -= backgroundWorker1_ProgressChanged;
backgroundWorker1.ProgressChanged += backgroundWorker1_ProgressChanged;
backgroundWorker1.RunWorkerCompleted -= backgroundWorker1_Completed;
backgroundWorker1.RunWorkerCompleted += backgroundWorker1_Completed;
backgroundWorker1.RunWorkerAsync();
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
using (var wc = new WebClient())
{
wc.DownloadProgressChanged += (sender, e) => backgroundWorker1.ReportProgress(sender, e);
using (var stream = wc.OpenRead("http://avatar.nimbuzz.com/getAvatar?jid=" + textBox1.Text))
{
e.Result = (Image.FromStream(stream));
}
}
}
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
progressBarX1.Value = e.ProgressPercentage;
progressBarX1.Refresh();
}
private void backgroundWorker1_Completed(object sender, DoWorkEventArgs e)
{
pictureBox1.Image = e.Result;
}
I just tried to write code for a progress bar with webclient
Please see my code.
private void button2_Click(object sender, EventArgs e)
{
if (textBox1.Text == "")
{
MessageBox.Show("Invalid Php Url");
}
else if (Uri.IsWellFormedUriString(textBox1.Text, UriKind.Absolute) == false)
{
MessageBox.Show("Invalid Php Url");
}
else
{
backgroundWorker1.RunWorkerAsync();
}
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
WebClient client = new WebClient();
client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressCallback);
client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadFileCallBack2);
client.DownloadFile(textBox1.Text, #"D:\test\test.zip");
}
void DownloadProgressCallback(object sender, DownloadProgressChangedEventArgs e)
{
this.progressBar1.Value = e.ProgressPercentage;
this.label6.Text = e.ProgressPercentage.ToString();
}
void DownloadFileCallBack2(object sender, AsyncCompletedEventArgs c)
{
MessageBox.Show("Download Completed");
}
But the event is not calling why?
is this because of the background worker or any other issues?
Please help me.
Best regards,
I think it is because the progress updated is called on a background thread and not the UI thread. Try passing in the webclient to the DoWork thread:
WebClient client = new WebClient();
client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(DownloadProgressCallback);
client.DownloadFileCompleted += new AsyncCompletedEventHandler(DownloadFileCallBack2);
backgroundWorker1.RunWorkerAsync(client);
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
WebClient client = (WebClient)e.Argument;
client.DownloadFile(textBox1.Text, #"D:\test\test.zip");
}
Your Progress Bar must be of the following conditions :
-Accurate
-Responsive and smooth
-Precise
-Appropriate
what is wrong with this code below? The conn_PageDeleted is coming from a background thread and i am trying to update a label every time i get a call back. I get an error stating
Parameter count mismatch.
Here is the code:
private void cmdDeletePage_Click(object sender, EventArgs e)
{
worker = new BackgroundWorker();
worker.DoWork += new DoWorkEventHandler(worker_DoWork);
worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
worker.RunWorkerAsync();
}
void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
lblDeleteStatus.Text = "";
MessageBox.Show("Complete");
}
void worker_DoWork(object sender, DoWorkEventArgs e)
{
Connecter conn = new Connecter("a", "m");
conn.PageDeleted += new Connecter.PageDeletedHandler(conn_PageDeleted);
bool success = conn.DeletePage(txtPageToDelete.Text, chkRecursive.Checked);
}
public delegate void UpdateLabelHandler(object sender, string name);
void conn_PageDeleted(object sender, string name)
{
if (this.InvokeRequired)
{
this.BeginInvoke(new UpdateLabelHandler(UpdateMe));
}
else
{
lblDeleteStatus.Text = name;
}
}
private void UpdateMe(object sender_, string name_)
{
lblDeleteStatus.Text = name_;
}
You should pass the parameters to the UpdateMe method, try this:
void conn_PageDeleted(object sender, string name)
{
if (this.InvokeRequired)
{
this.BeginInvoke(new UpdateLabelHandler(UpdateMe), new object[] {sender, name}); //<-- the update goes here
}
else
{
lblDeleteStatus.Text = name;
}
}
Your delegate has to match the signature of the event handler, something like this:
public delegate void UpdateLabelHandler(object sender, string strArgs);
Edit: Since you have edited the code to include this ... I will amend this accordingly....
Looking at your edited code, I have to question this:
void worker_DoWork(object sender, DoWorkEventArgs e)
{
Connecter conn = new Connecter("a", "m");
conn.PageDeleted += new Connecter.PageDeletedHandler(conn_PageDeleted);
bool success = conn.DeletePage(txtPageToDelete.Text, chkRecursive.Checked);
}
You are wiring up a 'PageDeleted' event handler....and call 'DeletePage' method after it, I presume that in turn invokes the event handler 'conn_PageDeleted' within the 'DoWork' body, it goes out of scope when the 'BackgroundWorker' thread is finished...and since 'conn' is in local scope of the 'worker_DoWork' method, that gets destroyed, and somehow your event handler gets messed up! Can you confirm this?
Hope this helps,
Best regards,
Tom.