How Can I Call Eventhandler

Question

0.00/5 (No votes)

See more:

if a have an eventHandlar shall i call it from If condition

C#

if (instance.NavigateError += new SHDocVw.DWebBrowserEvents2_NavigateErrorEventHandler(instance_NavigateError))

but its not working, actually i need to get response whether its calling or not?

please help if u have any other idea.

C#

private void button6_Click(object sender, EventArgs e)
        {

            

            SHDocVw.WebBrowser instance = (SHDocVw.WebBrowser)webBrowser1.ActiveXInstance;
            webBrowser1.Navigate("http://www.g4ogle.com/");
            

            instance.NavigateError += new SHDocVw.DWebBrowserEvents2_NavigateErrorEventHandler(instance_NavigateError);
            string asj = instance.StatusBar.GetType().ToString();
         
           
            
            
        }
        void instance_NavigateError(object pDisp, ref object URL, ref object Frame, ref object StatusCode, ref bool Cancel)
        {

            string filename = textBox1.Text;

            string fileName = filename.Substring(0, filename.LastIndexOf((".")));
            fileName += ".txt";
            if (File.Exists(fileName))
            {
                File.Delete(fileName);
            }
            //  string asg = Ret[0].ToString();
            int name = Convert.ToInt32(StatusCode);
            //ret1.Add("----" + "The URL '" + url + "' is Not valid.");
            // MessageBox.Show("error on page");

            Ret.Add("----" + "The URL '" + URL + "' is Not valid.");
            //File.AppendAllLines(fileName, Ret);
            MessageBox.Show("Completed......", "Info Box", MessageBoxButtons.OK, MessageBoxIcon.Information);



        }

Posted 11-Mar-14 20:06pm

Ashwani Gusain

Updated 12-Mar-14 0:17am

v2

Add a Solution

Comments

Vedat Ozan Oner 12-Mar-14 5:15am

why don't you use http://msdn.microsoft.com/en-us/library/system.windows.forms.webbrowser%28v=vs.110%29.aspx

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

OriginalGriff · Answer 1 · 2014-03-11T23:19:00

Solution 1

No, you don't do that.

There is no point in testing the value of a event handler addition: it will never be false because it does not return a bool value. It doesn't return any value! So all you will get is a compiler error about not being able to convert a void to a bool...

And you don't "call" event handlers - you raise the event in response to some stimuli, usually a user input of some kind, and the system calls all the event handler methods that are registered for that event for you.

I think that you are a little confused as to what events are - perhaps it would be a good idea to read back through your lecture notes and think about it a little more before you try leaping into code!

Posted 11-Mar-14 23:19pm

OriginalGriff

Comments

Ashwani Gusain 12-Mar-14 5:43am

Thanks Griff but sometime its calling but not every time as i checked in my code, you are right it always true, but why its calling some or not calling sometime?

OriginalGriff 12-Mar-14 5:46am

Show us code that compiles, and we might be able to help...

Ashwani Gusain 12-Mar-14 6:18am

hi griff please check updated code.

OriginalGriff 12-Mar-14 6:39am

That code is pretty much wrong: you are adding an event handler every time the user presses the button! And...you add it after the Navigate method is called, so it is quite possible that the error will have occurred before the handler is added, so the method will not be called every time there is a problem.

You only need to add the handler once: preferably when the WebBrowser instance is created. So if you are adding it to you form at design time, then add it in the Events panel of the Properties pane for the WebBrowser. If you manually create the instance and add it to your form, then add the handler at that point, not on the button click.

Hopefully, doing that will get rid of your problem!

Ashwani Gusain 12-Mar-14 6:55am

Hi Griff, as i mentioned earlier that code is working fine but the main concern is whenever that navigate url got wrong url it will call to instance_Navigateerror function. but my question is after calling from "instance.NavigateError += new SHDocVw.DWebBrowserEvents2_NavigateErrorEventHandler(instance_NavigateError);" , it is possible to get any clue about it will call or not?

OriginalGriff 12-Mar-14 7:02am

No - that's the whole idea of events.
If there is a problem, the event handler will be called - if there isn't it won't. There is no "other indication".

And as for "is working fine" - no it isn't! It may seem to be, but you do need to address the issues I raised because what seems to be working can go horribly wrong if you don't!

lukeer · Answer 2 · 2014-03-11T23:42:00

Solution 2

If you need something to happen whenever the event handler is called, then include it in the event handler.

If you want to call the event handler regardles of whether the related event is raised or not, you can do that like you would call every other method.

Posted 11-Mar-14 23:42pm

lukeer