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@hmcclungiii
Last active September 27, 2021 23:57
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C# Webbrowser Wrapper Control, used to be able to wait until a page completely loads prior to taking action on it. For web automation projects.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms;
public partial class browserwrapper : System.Windows.Forms.WebBrowser
{
/// <summary>
/// Designer variable used to keep track of non-visual components.
/// </summary>
private System.ComponentModel.IContainer components;
/// <summary>
/// Disposes resources used by the control.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing) {
if (components != null) {
components.Dispose();
}
}
base.Dispose(disposing);
}
/// <summary>
/// This method is required for Windows Forms designer support.
/// Do not change the method contents inside the source code editor. The Forms designer might
/// not be able to load this method if it was changed manually.
/// </summary>
private void InitializeComponent()
{
//
//browserwrapper
//
//Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
this.Name = "browserwrapper";
}
/// <summary>
/// This event is raised when the current document is entirely complete,
/// and no more navigation is expected to take place for it to load.
/// </summary>
/// <author>hmcclungiii</author>
/// <date>2/21/2014</date>
public event AbsolutelyCompleteEventHandler AbsolutelyComplete;
public delegate void AbsolutelyCompleteEventHandler(object sender, EventArgs e);
private int _onNavigatingCount = 0;
private int _onNavigatedCount = 0;
private int _onDocumentCompleteCount = 0;
/// <summary>
/// This method is used to clear the counters. Should not be used
/// externally, but I left it open for testing, and just in case
/// scenarios
/// </summary>
/// <author>hmcclungiii</author>
/// <date>2/21/2014</date>
public void ClearCounters()
{
_onNavigatingCount = 0;
_onNavigatedCount = 0;
_onDocumentCompleteCount = 0;
}
/// <summary>
/// This property returns true when all the counters have become equal
/// signifying that the navigation has completely completed
/// </summary>
/// <author>hmcclungiii</author>
/// <date>2/21/2014</date>
public bool Busy {
get {
//sometimes the first navigating event isn't fired so we just have to make sure the navigating count is
//more than the navigated, navigated should never be more than navigating
bool bBusy = !(_onNavigatingCount <= _onNavigatedCount);
//if our navigating counts check out, we should always have a documentcompleted count
//for each navigated event that is fired
if (!bBusy)
{
bBusy = (_onNavigatedCount > _onDocumentCompleteCount);
}
else
{
bBusy = !(_onNavigatedCount == _onDocumentCompleteCount);
if (!bBusy) bBusy=!(_onNavigatedCount>0);
}
return bBusy;
}
}
/// <summary>
/// This method is used to wait until the page has completely loaded. Use
/// after calling a submit, or click, or similar method to not execute further
/// code in the calling class until it has completed. Also helps to reduce
/// processor load
/// </summary>
/// <author>hmcclungiii</author>
/// <date>2/21/2014</date>
public void WaitUntilComplete()
{
//first we wait to make sure it starts
while (!Busy) {
Application.DoEvents();
//we should sleep for a moment to let the processor have a timeslice
//for something else - in other words, don't hog the resources
System.Threading.Thread.Sleep(1);
}
//now we wait until it is done
while (Busy) {
Application.DoEvents();
//we should sleep for a moment to let the processor have a timeslice
//for something else - in other words, don't hog the resources
System.Threading.Thread.Sleep(1);
}
}
public browserwrapper()
{
this.InitializeComponent();
}
//we have to catch the following three event callers to keep a count
//of them so that we will be able to determine when the navigation
//process actually completes
protected override void OnNavigating(WebBrowserNavigatingEventArgs e)
{
_onNavigatingCount += 1;
base.OnNavigating(e);
if (!Busy)
OnAbsolutelyComplete();
}
protected override void OnNavigated(WebBrowserNavigatedEventArgs e)
{
_onNavigatedCount += 1;
base.OnNavigated(e);
if (!Busy)
OnAbsolutelyComplete();
}
protected override void OnDocumentCompleted(WebBrowserDocumentCompletedEventArgs e)
{
_onDocumentCompleteCount += 1;
base.OnDocumentCompleted(e);
if (!Busy)
OnAbsolutelyComplete();
}
/// <summary>
/// This method should be used in place of the Navigate method to navigate to
/// a specific URL. The navigate method was not overridden because it might
/// be required in future modifications to have access to both methods. When
/// calling this NavigateAndWait method, control will not be returned to the
/// calling class until the document has completely loaded
/// </summary>
/// <author>hmcclungiii</author>
/// <date>2/21/2014</date>
public void NavigateAndWait(string URL)
{
ClearCounters();
Navigate(URL);
WaitUntilComplete();
}
protected void OnAbsolutelyComplete()
{
ClearCounters();
if (AbsolutelyComplete != null) {
AbsolutelyComplete(this, new EventArgs());
}
}
}
@Radzhab
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Radzhab commented Nov 24, 2015

How use this snippet?

@spanwich
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Thank you, This saved us a lot.

@lautarobusto
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Thank you, this is VERY helpfull

@javierguerrero
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Excelent! Thank you!

@jsfontana
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Hello. Do you have an example for this use? Thank you for your apport. Sebastián from Argentine.

@soufianetahiri
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its a custom control that inherits from WebBrowser ctrl so you can use it just a normal WebBrowser control

@soufianetahiri
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Sometimes Busy runs into infinite loop and even if the document is fully loaded it stills considered as Busy...(especially if we have some async calls in the web document) Trying to figure this out .. but will be happy If you give suggestions :)

@jocgoran
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Hello, thank a lot. I implemented it, have still to test it in my scenario, because I don'r really understand it yet.
If I run the NavigateAndWait() in a separate thread, than I have to write a thread.join? Ineed the thread , because I run the Browser in separate windows and so I can also access the GUI of main window.
Another question is, to make sure the document is loaded after InvokeMember("click") on htmlElement, is it enought to call the
ClearCounters();
htmlElements[i].InvokeMember("click"));
WaitUntilComplete();
?

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