Develop Reference

disable "this document has been modified"-message

I am changing the content on my webbrowser control using 2 different methods. I am only able to disable the message in one situation.
method 1:
I just need to add some text at the bottom of the page (i don't get the message)
string s = browser.DocumentText + "<a>Extra Text</a>";
browser.Document.Write(string.Empty);
browser.DocumentText=s;
method 2:
When i try to create a new element and add it to the webbrowser I still get the "this document has been modified"-message. Can i disable this message?
HtmlElement element = browser.Document.GetElementById("myId");
HtmlElement newElement = browser.Document.CreateElement("a");
newElement.InnerText = "Extra text";
element.AppendChild(newElement);

Try
myWebBrowser.Document.ExecCommand("Refresh", False, "")

Invoke button click programmatically

I want to programmatically click button on a webpage with source like this
<input alt="BusiBtn" class="aButtn" type="submit" value="Search" tabindex="16">
When I do
WebBrowser b = new WebBrowser();
b.Navigate(URL);
while (b.ReadyState != WebBrowserReadyState.Complete)
{
Application.DoEvents();
}
b.Document.GetElementByID("BusiBtn").InvokeMember("click");
I get "Object reference not set to an instance of object error".
Can somebody help.
Thanks
Rashmi

What you can do in this case simply find all the HtmlElements having input tag. If you need to invoke all the input tags in general, then just invoke click on them. And if you need only the above input element, then filter all the input tags to search for the specific tag with the attribute values like above. Please have a look at the following code:
HtmlElementCollection elems = b.Document.GetElementsByTagName("input");
foreach (HtmlElement elem in elems)
{
string altStr = elem.GetAttribute("alt");
string classStr = elem.GetAttribute("class");
string typeStr = elem.GetAttribute("type");
string valueStr = elem.GetAttribute("value");
string tabindexStr = elem.GetAttribute("tabindex");
if((altStr == "BusiBtn") && (classStr == "aButtn") && (typeStr == "submit") && (valueStr == "Search") && (tabindexStr == "16"))
{
elem.InvokeMember("click");
break;
}
}

You're using the wrong field.
alt is for alternative text.
You have not actually given that button an id of BusiBtn.
Try:
<input id="BusiBtn" class="aButtn" type="submit" value="Search" tabindex="16">
The clue is in the GetElementByID call. It's not called GetElementByAlt for a reason ;)

add 'name' property to input tag and then use GetElementsByName property

You should use the GetElementsByTagName method instead of GetElementById to get all Input-Elements on the page and then cycle through using GetAttribute. An example can be found here http://msdn.microsoft.com/en-us/library/system.windows.forms.htmldocument.getelementsbytagname(v=vs.110).aspx.

GetElementById without id and name HOW?

I need to click the button "Add" in the post new wordpress form, this button is to add tags to the post , the trouble is that button don't have the value and id propertie. Is just like that
the html for the button
input type="button" class="button tagadd" value="Add" tabindex="3"
my tries
webBrowser1.Document.GetElementById("button tagadd").InvokeMember("click");
webBrowser1.Document.GetElementById("Add").InvokeMember("click");

"GetElementById without id"
:-)
Unless you can change the markup for the button
What you need now is to traverse the entire DOM and look for a button in a known place. I'd suggest adding jquery if not already exist to be able for easier dom manipulation/search.
If you add jquery you could do something like $(".tagadd").click()

You could try doing
webBrowser1.document.getElementsByClassName("tagadd")
EDIT: Here is a script to create the getElementsByClassName function if it's not available http://robertnyman.com/2008/05/27/the-ultimate-getelementsbyclassname-anno-2008/
There is also this http://msdn.microsoft.com/en-us/library/system.windows.forms.htmldocument.getelementsbytagname.aspx but I've never used it.

Add an ID. Even if you're dynamically generating the buttons this should be trivial.
If you're using jQuery,
$('.tagadd')
will return a collection of everything with the tagadd class applied. You can further filter this by the other classes (button, etc)
Use this:
onload=function(){
if (document.getElementsByClassName == undefined) {
document.getElementsByClassName = function(className)
{
var hasClassName = new RegExp("(?:^|\s)" + className + "(?:$|\s)");
var allElements = document.getElementsByTagName("*");
var results = [];
var element;
for (var i = 0; (element = allElements[i]) != null; i++) {
var elementClass = element.className;
if (elementClass
&& elementClass.indexOf(className) != -1
&& hasClassName.test(elementClass))
results.push(element);
}
return results;
}
}
}
and another
Some browsers provide the method getElementsByClassName() which lets you select by class without using jQuery (which is a bit heavy if this is all you need). I haven't tested this so I'm not sure how widely it's supported.
Did I mention that you should give everything an ID?

use TagName isteed for example
var elems = webBrowser1.Document.GetElementsByTagName("input");
foreach (HtmlElement elem in elems)
{
if (elem.GetAttribute("class") == "button tagadd")
{
elem.InvokeMember("click");
}
}

How to display the string html contents into webbrowser control?

I have a C# win app program. I save the text with html format in my database but I want to show it in a webbrowser to my user.How to display the string html contents into webbrowser control?

Try this:
webBrowser1.DocumentText =
"<html><body>Please enter your name:<br/>" +
"<input type='text' name='userName'/><br/>" +
"<a href='http://www.microsoft.com'>continue</a>" +
"</body></html>";

Instead of navigating to blank, you can do
webBrowser1.DocumentText="0";
webBrowser1.Document.OpenNew(true);
webBrowser1.Document.Write(theHTML);
webBrowser1.Refresh();
No need to wait for events or anything else. You can check the MSDN for OpenNew, while I have tested the initial DocumentText assignment in one of my projects and it works.

As commented by Thomas W. - I almost missed this comment but I had the same issues so it's worth rewriting as an answer I think.
The main issue being that after the first assignment of webBrowser1.DocumentText to some html, subsequent assignments had no effect.
The solution as linked by Thomas can be found in detail at http://weblogs.asp.net/gunnarpeipman/archive/2009/08/15/displaying-custom-html-in-webbrowser-control.aspx however I will summarize below in case this page becomes unavailable in the future.
In short, due to the way the webBrowser control works, you must navigate to a new page each time you wish to change the content. Therefore the author proposes a method to update the control as:
private void DisplayHtml(string html)
{
webBrowser1.Navigate("about:blank");
if (webBrowser1.Document != null)
{
webBrowser1.Document.Write(string.Empty);
}
webBrowser1.DocumentText = html;
}
I have however found that in my current application I get a CastException from the line if(webBrowser1.Document != null). I'm not sure why this is, but I've found that if I wrap the whole if block in a try catch the desired effect still works. See:
private void DisplayHtml(string html)
{
webBrowser1.Navigate("about:blank");
try
{
if (webBrowser1.Document != null)
{
webBrowser1.Document.Write(string.Empty);
}
}
catch (CastException e)
{ } // do nothing with this
webBrowser1.DocumentText = html;
}
So every time the function to DisplayHtml is executed I receive a CastException from the if statement, so the contents of the if statement are never reached. However if I comment out the if statement so as not to receive the CastException, then the browser control doesn't get updated. I suspect there is another side effect of the code behind the Document property which causes this effect despite the fact that it also throws an exception.
Anyway I hope this helps people.

For some reason the code supplied by m3z (with the DisplayHtml(string) method) is not working in my case (except first time). I'm always displaying html from string. Here is my version after the battle with the WebBrowser control:
webBrowser1.Navigate("about:blank");
while (webBrowser1.Document == null || webBrowser1.Document.Body == null)
Application.DoEvents();
webBrowser1.Document.OpenNew(true).Write(html);
Working every time for me. I hope it helps someone.

Simple solution, I've tested is
webBrowser1.Refresh();
var str = "<html><head></head><body>" + sender.ToString() + "</body></html>";
webBrowser1.DocumentText = str;

webBrowser.NavigateToString(yourString);

Here is a little code. It works (for me) at any subsequent html code change of the WebBrowser control. You may adapt it to your specific needs.
static public void SetWebBrowserHtml(WebBrowser Browser, string HtmlText)
{
if (Browser != null)
{
if (string.IsNullOrWhiteSpace(HtmlText))
{
// Putting a div inside body forces control to use div instead of P (paragraph)
// when the user presses the enter button
HtmlText =
#"<html>
<head>
<meta http-equiv=""Content-Type"" content=""text/html; charset=UTF-8"" />
</head>
<div></div>
<body>
</body>
</html>";
}
if (Browser.Document == null)
{
Browser.Navigate("about:blank");
//Wait for document to finish loading
while (Browser.ReadyState != WebBrowserReadyState.Complete)
{
Application.DoEvents();
System.Threading.Thread.Sleep(5);
}
}
// Write html code
dynamic Doc = Browser.Document.DomDocument;
Doc.open();
Doc.write(HtmlText);
Doc.close();
// Add scripts here
/*
dynamic Doc = Document.DomDocument;
dynamic Script = Doc.getElementById("MyScriptFunctions");
if (Script == null)
{
Script = Doc.createElement("script");
Script.id = "MyScriptFunctions";
Script.text = JavascriptFunctionsSourcecode;
Doc.appendChild(Script);
}
*/
// Enable contentEditable
/*
if (Browser.Document.Body != null)
{
if (Browser.Version.Major >= 9)
Browser.Document.Body.SetAttribute("contentEditable", "true");
}
*/
// Attach event handlers
// Browser.Document.AttachEventHandler("onkeyup", BrowserKeyUp);
// Browser.Document.AttachEventHandler("onkeypress", BrowserKeyPress);
// etc...
}
}

Old question, but here's my go-to for this operation.
If browser.Document IsNot Nothing Then
browser.Document.OpenNew(True)
browser.Document.Write(My.Resources.htmlTemplate)
Else
browser.DocumentText = My.Resources.htmlTemplate
End If
And be sure that any browser.Navigating event DOES NOT cancel "about:blank" URLs. Example event below for full control of WebBrowser navigating.
Private Sub browser_Navigating(sender As Object, e As WebBrowserNavigatingEventArgs) Handles browser.Navigating
Try
Me.Cursor = Cursors.WaitCursor
Select Case e.Url.Scheme
Case Constants.App_Url_Scheme
Dim query As Specialized.NameValueCollection = System.Web.HttpUtility.ParseQueryString(e.Url.Query)
Select Case e.Url.Host
Case Constants.Navigation.URLs.ToggleExpander.Host
Dim nodeID As String = query.Item(Constants.Navigation.URLs.ToggleExpander.Parameters.NodeID)
:
:
<other operations here>
:
:
End Select
Case Else
e.Cancel = (e.Url.ToString() <> "about:blank")
End Select
Catch ex As Exception
ExceptionBox.Show(ex, "Operation failed.")
Finally
Me.Cursor = Cursors.Default
End Try
End Sub

The DisplayHtml(string html) recommended by m3z worked for me.
In case it helps somebody, I would also like to mention that initially there were some spaces in my HTML that invalidated the HTML and so the text appeared as a string. The spaces were introduced (around the angular brackets) when I pasted the HTML into Visual Studio. So if your text is still appearing as text after you try the solutions mentioned in this post, then it may be worth checking that the HTML syntax is correct.

How to programmatically click on text input in WebBrowser using C#

I have opened a website using WebBrowser. Now I would like to programmatically click input text (textbox) field. I can not use focus because this website uses JS to unlock this field only if it's clicked and I've tried also this:
Object obj = ele.DomElement;
System.Reflection.MethodInfo mi = obj.GetType().GetMethod("click");
mi.Invoke(obj, new object[0]);
But it returns mi = null. How to do this so it will work?

Very similar to my answer on your other question.
Get an HtmlElement respresentative of your textbox, and call HtmlElement.InvokeMember("click") on it.

If you can, use:
webbrowser1.Navigate("javascript:document.forms[0].submit()")
or something similar. For me, it's been much easier and more accurate.

To fill-up a text field on a webpage:
string code ="";
code = code + "var MyVar=document.getElementById('tbxFieldNameOnWebPage');if(MyVar != null) MyVar.value = 'SOMEVALUE';";
domDocument.parentWindow.execScript(code, "JScript");
Then To Click a button on a webpage:
code = "";
code = "var SignupFree = document.getElementsByTagName('button')[1];";
code = (code + " SignupFree.click();");
domDocument.parentWindow.execScript(code, "JScript");
you can also use document.getElementById('buttonID'); instead of document.getElementsByTagName('button')[1]; but an id must be provided for this button on that particular webpage.

Use InvokeMethhod on HtmlElement or Browser.InvokeScript function.