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C# IE11 Automation - Cannot Connect To Open IE Window

I'm trying to connect to an Internet Explorer window that is already open. Once connected I need to send some keystrokes (via SendKeys) to the IE window for some processing. I've got the following code below that works up until the SendKeys command. It finds the IE window titled "Graphics Database". When it hits "SendKeys.Send("{TAB}");" I get the error "An unhandled exception of type 'System.NullReferenceException' occurred".
Additional information: I also get the following on the NullReferenceException error. The weird thing is if I code to open a new IE window and then use SendKeys it works fine. Connecting to an existing windows seems to cause this issue.
SendKeys cannot run inside this application because the application is not handling Windows messages. Either change the application to handle messages, or use the SendKeys.SendWait method.
Can anyone please help me figure out what to do to fix this?
Andy
InternetExplorer IE = null;
// Get all browser objects
ShellWindows allBrowsers = new ShellWindows();
if (allBrowsers.Count == 0)
{
throw new Exception("Cannot find IE");
}
// Attach to IE program process
foreach (InternetExplorer browser in allBrowsers)
{
if (browser.LocationName == "Graphics Database")
{
MessageBox.Show ("Found IE browser '" + browser.LocationName + "'");
IE = (InternetExplorer)browser;
}
}
IE.Visible = true;
System.Threading.Thread.Sleep(2000);
SendKeys.Send("{TAB}");
SendKeys.Send("G1007");
SendKeys.Send("{ENTER}");

I was able to resolve this issue. I could never get the IE.Visible = true to work. This seemed to do nothing in my code. I had to use the SetForegroundWindow() to set the focus to the IE window.
// Find the IE window
int hWnd = FindWindow(null, "Graphics Database - Internet Explorer");
if (hWnd > 0) // The IE window was found.
{
// Bring the IE window to the front.
SetForegroundWindow(hWnd);
This site helped me immensely with getting the SetForegroundWindow() working.
http://forums.codeguru.com/showthread.php?460402-C-General-How-do-I-activate-an-external-Window

Andy please bear with me as this will be long. First you are going to want to look mshtml documentation and Dom. https://msdn.microsoft.com/en-us/library/aa741314(v=vs.85).aspx I don't know why automation is so convoluted but it is. The UIautomation class works great for windows apps but has nothing really for IE that I've been able to find. Others will point to third parties like waitn and selenium. Waitn appears to no longer be supported and selenium won't let you grab an open IE browser. I have gone down this path recently because I wanted to be able to create an app to store my web passwords and auto fill them in since I can't save my username and passwords in browser due to security restrictions. I have an example here and hope it helps. First open up IE and navigate to http://aavtrain.com/index.asp. Then have a console project with mshtml referenced and shdocvw. Here is code below. It gets the window then finds elements for username, password, and submit. then populates the username and password and clicks the submit button. I don't have a login to this site so it won't log you in. I have been using it for my testing. Problem I have is sites with javascript login forms. If you get further with this info please post back as I am still trying to evolve the concepts and create something reusable.
SHDocVw.ShellWindows shellWindows = new SHDocVw.ShellWindows();
Console.WriteLine("Starting Search\n\n\n");
foreach (SHDocVw.InternetExplorer ie in shellWindows)
{
if (ie.LocationURL.Contains("aavtrain"))
{
Console.WriteLine(ie.LocationURL);
Console.WriteLine("\n\n\n\n");
Console.WriteLine("FOUND!\n");
mshtml.HTMLDocument document = ie.Document;
mshtml.IHTMLElementCollection elCol = document.getElementsByName("user_name");
mshtml.IHTMLElementCollection elCol2 = document.getElementsByName("password");
mshtml.IHTMLElementCollection elCol3 = document.getElementsByName("Submit");
Console.WriteLine("AutofillPassword");
foreach (mshtml.IHTMLInputElement i in elCol)
{
i.defaultValue = "John";
}
foreach (mshtml.IHTMLInputElement i in elCol2)
{
i.defaultValue = "Password";
}
Console.WriteLine("Will Click Button in 2 seconds");
Thread.Sleep(2000);
foreach (mshtml.HTMLInputButtonElement i in elCol3)
{
i.click();
}
}
}
Console.WriteLine("Finished");

writing data from C# to Excel interrupted by opening Excel Window

While my C# program writes data continuously to an Excel spreadsheet, if the end user clicks on the upper right menu and opens the
Excel Options window, this causes following exception:
System.Runtime.InteropServices.COMException with HRESULT: 0x800AC472
This interrupts the data from being written to the spreadsheet.
Ideally, the user should be allowed to do this without causing an exception.
The only solution I found to this error code was to loop and wait until the exception went away:
Exception from HRESULT: 0x800AC472
which effectively hangs the app, data is not written to Excel and the user is left in the dark about the problem.
I thought about disabling the main menu of Excel while writing to it, but cannot find a reference on how to do this.
My app supports Excel 2000 to 2013.
Here is how to reproduce the issue:
Using Visual Studio Express 2013 for Windows Desktop, .NET 4.5.1 on Windows 7 64-bit with Excel 2007, create a new Visual C# Console Application project.
Add reference to "Microsoft ExceL 12.0 Object Library" (for Excel) and to "System.Windows.Forms" (for messagebox).
Here is the complete code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading.Tasks;
using System.Threading; // for sleep
using System.IO;
using System.Runtime.InteropServices;
using System.Reflection;
using Microsoft.Win32;
using Excel = Microsoft.Office.Interop.Excel;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
int i = 3; // there is a split pane at row two
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
try
{
object misValue = System.Reflection.Missing.Value;
xlApp = new Excel.Application();
xlApp.Visible = false;
xlWorkBook = xlApp.Workbooks.Add(misValue);
xlApp.Visible = true;
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
// next 2 lines for split pane in Excel:
xlWorkSheet.Application.ActiveWindow.SplitRow = 2;
xlWorkSheet.Application.ActiveWindow.FreezePanes = true;
xlWorkSheet.Cells[1, 1] = "Now open the";
xlWorkSheet.Cells[2, 1] = "Excel Options window";
}
catch (System.Runtime.InteropServices.COMException)
{
System.Windows.Forms.MessageBox.Show("Microsoft Excel does not seem to be installed on this computer any longer (although there are still registry entries for it). Please save to a .tem file. (1)");
return;
}
catch (Exception)
{
System.Windows.Forms.MessageBox.Show("Microsoft Excel does not seem to be installed on this computer any longer (although there are still registry entries for it). Please save to a .tem file. (2)");
return;
}
while(i < 65000)
{
i++;
try
{
xlWorkSheet.Cells[i, 1] = i.ToString();
Thread.Sleep(1000);
}
catch (System.Runtime.InteropServices.COMException)
{
System.Windows.Forms.MessageBox.Show("All right, what do I do here?");
}
catch (Exception)
{
System.Windows.Forms.MessageBox.Show("Something else happened.");
}
}
Console.ReadLine(); //Pause
}
}
}
Lanch the app, Excel appears and data is written to it. Open the Excel options dialog window from the menu and up pops the error:
An exception of type 'System.Runtime.InteropServices.COMException' occurred in mscorlib.dll and wasn't handled before a managed/native boundary
Additional information: Exception from HRESULT: 0x800AC472
Click on Continue and my message box "All right, what do I do here?" appears.
Please advise?
Best regards,
Bertrand

We finally went all the way to Microsoft Support with this issue. Their final response was:
I am able to reproduce the issue. I researched on this further and
found that this behaviour is expected and by design. This
exception, 0x800AC472 – VBA_E_IGNORE, is thrown because Excel is busy
and will not service any Object Model calls. Here is one of the
discussions that talks about this.
http://social.msdn.microsoft.com/Forums/vstudio/en-US/9168f9f2-e5bc-4535-8d7d-4e374ab8ff09/hresult-800ac472-from-set-operations-in-excel?forum=vsto The work around I see is to explicitly catch this exception and retry
after sometime until your intended action is completed.
Since we cannot read the minds of the user who might decide to open a window or take a note without realizing the soft has stopped logging (if you mask the error), we decided to work around using:
xlWorkSheet.EnableSelection = Microsoft.Office.Interop.Excel.XlEnableSelection.xlNoSelection;
to lock the Excel window UI. We provide an obvious "unlock" button but when the user clicks it, he is sternly warned in a messagebox along with a "Do you wish to continue?"

Make Excel Interactive is a perfect solution. The only problem is if the user is doing something on Excel at the same time, like selecting range or editing a cell. And for example your code is returning from a different thread and trying to write on Excel the results of the calculations. So to avoid the issue my suggestions is:
private void x(string str)
{
while (this.Application.Interactive == true)
{
// If Excel is currently busy, try until go thru
SetAppInactive();
}
// now writing the data is protected from any user interaption
try
{
for (int i = 1; i < 2000; i++)
{
sh.Cells[i, 1].Value2 = str;
}
}
finally
{
// don't forget to turn it on again
this.Application.Interactive = true;
}
}
private void SetAppInactive()
{
try
{
this.Application.Interactive = false;
}
catch
{
}
}

xlApp = new Excel.Application();
xlApp.Interactive = false;

What I have done successfully is to make a temp copy of the target excel file before opening it in code.
That way I can manipulate it independent of the source document being open or not.

One possible alternative to automating Excel, and wrestling with its' perculiarities, is to write the file out using the OpenXmlWriter writer (DocumentFormat.OpenXml.OpenXmlWriter).
It's a little tricky but does handle sheets with > 1 million rows without breaking a sweat.
OpenXml docs on MSDN

Since Interop does cross threading, it may lead to accessing same object by multiple threads, leading to this exception, below code worked for me.
bool failed = false;
do
{
try
{
// Call goes here
failed = false;
}
catch (System.Runtime.InteropServices.COMException e)
{
failed = true;
}
System.Threading.Thread.Sleep(10);
} while (failed);

Attach to existing Excel Instance

I'm trying to determine whether or not an instance of Excel of running with a particular file open, and if so attach to it so I can control that instance.
I've searched around and the majority of what I've got have come from this question. It has a reference to another site, but unfortunately it's dead for me so I cannot read up on it.
My code so far is;
//Is Excel open?
if (Process.GetProcessesByName("EXCEL").Length != 0)
{
Process[] processes = Process.GetProcesses();
foreach (Process process in processes)
{
//Find the exact Excel instance
if (process.ProcessName.ToString() == "EXCEL" && process.MainWindowTitle == ("Microsoft Excel - " + fileName))
{
//Get the process ID of that instance
int processID = (int)Process.GetProcessById(process.Id).MainWindowHandle;
//Attach to the instance...
Excel.Application existingExcel = (Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject(process.Id);
}
}
}
So far I've managed to get the process ID of the instance I want to attach to, but I'm lost when it comes to using that ID.
Any ideas on how to proceed?

Marshal.GetActiveObject() doesn't take a process ID as a parameter. What you want is:
Marshal.GetActiveObject("Excel.Application");
Note that this doesn't require keeping track of the process at all, there just needs to be one.
It gets a lot more complicated if you can have multiple processes and want to attach to a specific one. That is where the answer to the other question comes in.
There is also a good article at http://blogs.msdn.com/b/andreww/archive/2008/11/30/starting-or-connecting-to-office-apps.aspx with a more full description of different ways of launching excel. Note that not all of them are necessarily up to date with Excel 2013, where having a single process for all Excel windows complicates things. For your purposes though, the GetActiveObject solution should be fine.

Kill particular instance of Winword

my application creates a new instance of winword embedded in a windows form.
new Microsoft.Office.Interop.Word.ApplicationClass()
Once the user finishes editing I close the window but the winword instance is still running in the background.
How can I kill that particular instance? I know how to kill all instances running on a machine but this isn't an option.

You need to call
application.Quit()
In your code.
One thing I had to do on my system (it's an excel processing tool) is do a process kill if after the Quit things were still going on.
var openedExcel = System.Diagnostics.Process.GetProcessesByName("EXCEL");
if (openedExcel.Any())
{
foreach (var excel in openedExcel)
{
try { excel.Kill(); }
catch { }
}
}

There are different methods for this (Marshal.ReleaseComObject is the most used I believe).
I suggest you should read the official documentation about releasing Office applications instances. it's available here: Microsoft .NET Development for Microsoft Office / Releasing COM Objects

I Suggest you combine / add to Flaviotsf's answer the following code - which will determine what actual process is on the run:
Process[] myProcList = Process.GetProcesses();
for (int i = 0; i <= myProcList.Length - 1; i ++) {
string strProcessName = myProcList [i].ProcessName;
string strProcessTitle = myProcList [i].MainWindowTitle();
//check for your process name.
if (strProcessName.ToLower().Trim().Contains("access")) {
myProcList [i].Kill();
}
}

Kill particular instance of Winword Document.
foreach (var process in Process.GetProcessesByName("WINWORD"))
{
if (process.MainWindowTitle.Contains("Temp")) // Temp is document name.
process.Kill();
}

How do I find out what 'processes' are accessing my Lucene.Net file?

I'm getting this exception when running some code to add text to a Lucene.net index:
The process cannot access the file
'E:\SomeProject\SomeProject.Webroot\App_Data\Lucene\segments.new'
because it is being used by another
process.
What's the easiest way of finding out what the 'other process' is? (I'm running on Win XP) Here's a stripped down code fragment (the exception is being thrown by the 'AddDocument' line after 50+ iterations) in case that's any help:
using l = Lucene.Net;
public void IndexText(List<TextToIndex> textToIndexList)
{
l.Analysis.Standard.StandardAnalyzer standardAnalyzer =
new l.Analysis.Standard.StandardAnalyzer();
l.Index.IndexWriter indexWriter =
new l.Index.IndexWriter(_LuceneIndexPath, standardAnalyzer, false);
foreach (TextToIndex textToIndex in textToIndexList)
{
l.Documents.Document luceneDoc =
CreateLuceneDoc(textToIndex.TypeId,
textToIndex.TextId,
textToIndex.Text,
textToIndex.Title,
textToIndex.ModifiedDate,
textToIndex.CultureCode);
indexWriter.AddDocument(luceneDoc);
}
indexWriter.Close();
}

You can use sysinternal's (now part of Microsoft) "process explorer" to find out what processes have what files open:
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx
When you run it, click on the "find handle" button (or from the menu find->find handle), then enter "segments.new" - it will show you any processes that have that file open.

Try "unlocker" http://www.emptyloop.com/unlocker/