CODEWITHSUNDEEP
c#winforms
Prachur
Prachur

Reputation: 1110

How to introduce lag between various events when using webbrowser contol in winform?

I am developing a c# winform app which controls a website using web browser. I need to perform many events on click of a single button, but many events do not take place until I use a message box to give some sort of lag between events. Below is the code 

private void button5_Click(object sender, EventArgs e)
{
    try
    {
        HtmlDocument webDoc = this.webBrowser1.Document;
        HtmlElementCollection aTags = webDoc.GetElementsByTagName("a");
        string selectedIssue;
        selectedIssue = AcknowledgeList.SelectedItem.ToString();
        foreach (HtmlElement aElement in aTags)
        {
            if (aElement.InnerText.Contains(selectedIssue))
            {
                aElement.InvokeMember("click");

                break;
            }
        }
        MessageBox.Show("Device Acknowledged");

        this.finalAcknowledge();
    }
    catch (NullReferenceException connectionError)
    {
        MessageBox.Show("Connection Error , try again");
    }
}

private void finalAcknowledge()
{
    try
    {
        HtmlDocument webDoc = this.webBrowser1.Document;

        HtmlElement changeNote = webDoc.GetElementById("@note");
        string comment = textBox1.Text;
        changeNote.SetAttribute("value", comment);

        HtmlElementCollection selectTags
            = webDoc.GetElementsByTagName("select");
        foreach (HtmlElement selectElement in selectTags)
        {
            if (selectElement.GetAttribute("name").Equals("status"))
            {
                selectElement.SetAttribute("value", "6");
            }
        }

        HtmlElement submitButton = webDoc.GetElementById("submit_button");
        submitButton.InvokeMember("click");
        this.button3.PerformClick();
        string selectedIssue;
        selectedIssue = AcknowledgeList.SelectedItem.ToString();
        AcknowledgeList.Items.Remove(AcknowledgeList.SelectedItem);
        AssignToList.Items.Add(selectedIssue);

        MessageBox.Show("Device Acknowledged");

        this.callShowAssigned();
    }
    catch (NullReferenceException connectionError)
    {
        MessageBox.Show("Connection Error , try again");
    }
}

Here I have used two message boxes to give some lag between events. I want to get rid of these message boxes and want some other method which can perfrom all the events and I do not have to interrupt the user with some message box or something that is visible

Upvotes: 0

Views: 298

Answers (1)

VikciaR
VikciaR

Reputation: 3412

Lag can be done with:

Thread.Sleep(time_to_sleep);

But in this case better to use event: http://msdn.microsoft.com/en-us/library/5d67hf8a.aspx

webBrowser1.DocumentCompleted+=OnPageLoaded;

When you aElement.InvokeMember("click"), you tell to webBrowser1 make some action: post/get to some page. So webbrowser begins job: it makes call to remote server, gets page, renders it. This take time, which can be longer or shorter. This call is made asynchronous, which means, that your code runs forward without waiting for webbrowser to finish. So what can you do? You can subscribe to webbrowser object events, which will hit when browser control finish work.

//Somewhere before InvokeMember
webBrowser1.DocumentCompleted+=OnPageLoaded;


private void OnPageLoaded(object sender,
        WebBrowserDocumentCompletedEventArgs e)
    {
    //Make your final acknowledgement
    //This method will be executed every time, when your page is loaded
    }

Upvotes: 2

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