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Creating an On-send prompt in Outlook with VSTO and in C#

I have a requirement to intercept the sending of a new email. All I want to do initially is ask the user "Are you sure you want to send?" and then to either proceed with the sending or cancel it depending on their response.
I found this code snippet which looks perfect for my needs but couldn't get it to work in a Win Forms test application either in VB.Net or after trying to convert it to C#. It then occurred to me that the code may only work in a VSTO Add-in (Is this correct?).
So I then used this Walkthrough to create a VSTO Add-in in C# and made sure that it worked as described, which it does (it pumps some text into the Subject and Body of a new message).
I have tried to add the first example which is in VB.Net into the working C# example but I'm a novice and don't know enough about VSTO or C# to see where I'm going wrong.
The code compiles without errors but when run, Outlook takes a long time loading the Add-in and displays a dialogue stating:
An add-in could not be found or loaded
and then:
Could not create an instance of startup object
PromptToFile_Plug_in.ThisAddIn in assembly PromptToFile Plug-in,
Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
Where am I going wrong?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.Diagnostics;
using Outlook = Microsoft.Office.Interop.Outlook;
using Office = Microsoft.Office.Core;
using System.Windows.Forms;
namespace PromptToFile_Plug_in
{
public partial class ThisAddIn
{
Outlook.Inspectors inspectors;
Outlook.Application myOlApp = new Outlook.Application();
private void ThisAddIn_Startup(object sender, System.EventArgs e)
{
inspectors = this.Application.Inspectors;
inspectors.NewInspector +=
new Microsoft.Office.Interop.Outlook.InspectorsEvents_NewInspectorEventHandler(Inspectors_NewInspector);
}
private void ThisAddIn_Shutdown(object sender, System.EventArgs e)
{
// Note: Outlook no longer raises this event. If you have code that
// must run when Outlook shuts down, see https://go.microsoft.com/fwlink/?LinkId=506785
}
void Inspectors_NewInspector(Microsoft.Office.Interop.Outlook.Inspector Inspector)
{
Outlook.MailItem mailItem = Inspector.CurrentItem as Outlook.MailItem;
if (mailItem != null)
{
if (mailItem.EntryID == null)
{
mailItem.Subject = "This text was added by using code";
mailItem.Body = "This text was added by using code";
}
}
}
private void Initialize_handler()
{
myOlApp = this.Application;
}
private void myOlApp_ItemSend(object Item, bool Cancel)
{
string prompt;
// prompt = "Are you sure you want to send " + Item.Subject + "?";
prompt = "Are you sure you want to send?";
MessageBox.Show(prompt, "Prompt to File", MessageBoxButtons.OKCancel);
//if (MessageBox.(prompt, Constants.vbYesNo + Constants.vbQuestion, "Sample") == Constants.vbNo)
// Cancel = true;
}
#region VSTO generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InternalStartup()
{
this.Startup += new System.EventHandler(ThisAddIn_Startup);
this.Shutdown += new System.EventHandler(ThisAddIn_Shutdown);
}
#endregion
}
}

First of all, there is no need to create a new Outlook Application instance in the add-in class:
Outlook.Application myOlApp = new Outlook.Application();
Instead, use the Application property available in your add-in class.
Second, there is no need to keep the following method because it will never be called:
private void Initialize_handler()
{
myOlApp = this.Application;
}
Unlike VBA, you can't subscribe to the events just declaring the source objects with keywords. Instead, you need to subscribe to the events in the code like you did for the NewInspector event. For example, the following code can be used for handling the ItemSend event in VSTO add-ins:
private void ThisAddIn_Startup(object sender, System.EventArgs e)
{
this.Application.ItemSend += new Microsoft.Office.Interop.Outlook.ApplicationEvents_11_ItemSendEventHandler(Application_ItemSend);
}
void Application_ItemSend(object Item, ref bool Cancel)
{
if (Item is Outlook.MailItem)
{
Outlook.MailItem mail = (Outlook.MailItem)Item;
// your code goes here
}
}
Finally, pay attention to the ref attribute for the Cancel parameter in the event handler signature.

Trouble attaching an event to a custom task pane. VSTO, Excel 2016

Background
I'm currently working on an application in VSTO2015 and Excel 2016. The application manages a number of CustomTaskPanes in different windows. I am trying to get // some code to fire when the task pane is opened or closed. In order to handle the various windows, I've implemented a structure very similar to this;
CustomTaskPane in Excel doesn't appear in new Workbooks
ThisAddIn.cs contains the following class;
public class TaskPaneManager
{
static Dictionary<string, Microsoft.Office.Tools.CustomTaskPane> _createdPanes = new Dictionary<string, Microsoft.Office.Tools.CustomTaskPane>();
/// <summary>
/// Gets the taskpane by name (if exists for current excel window then returns existing instance, otherwise uses taskPaneCreatorFunc to create one).
/// </summary>
/// <param name="taskPaneId">Some string to identify the taskpane</param>
/// <param name="taskPaneTitle">Display title of the taskpane</param>
/// <param name="taskPaneCreatorFunc">The function that will construct the taskpane if one does not already exist in the current Excel window.</param>
public static Microsoft.Office.Tools.CustomTaskPane GetTaskPane(string taskPaneId, string taskPaneTitle, Func<UserControl> taskPaneCreatorFunc)
{
string key = string.Format("{0}({1})", taskPaneId, Globals.ThisAddIn.Application.Hwnd);
string title = taskPaneId;
string windowId = Globals.ThisAddIn.Application.Hwnd.ToString();
if (!_createdPanes.ContainsKey(key))
{
var customTaskPane = taskPaneCreatorFunc();
var pane = Globals.ThisAddIn.CustomTaskPanes.Add(customTaskPane, taskPaneTitle);
_createdPanes[key] = pane;
//
// Set the task pane width as set in the App.Config
//
pane.Width = Convert.ToInt32(ConfigurationManager.AppSettings["TaskPaneWidth"]);
}
return _createdPanes[key];
}
....
My calls from Ribbon.cs;
private void btnUploadWizard_Click(object sender, RibbonControlEventArgs e)
{
// Check for configuration sheet first.
string title = "Upload Wizard";
TaskPaneManager.isConfigurationCreated();
var UploadWizardTaskpane = TaskPaneManager.GetTaskPane(title, title, () => new TaskPaneUploadWizard());
UploadWizardTaskpane.Visible = !UploadWizardTaskpane.Visible;
}
The Problem: Event Handlers
I'm having difficulty getting an event handler to fire. I can't tell what I'm doing wrong. In the TaskPaneDesigner I am attaching the event using this.VisibleChanged += new System.EventHandler(this.TaskPaneUploadWizard_VisibleChanged);, and then defining it in my TaskPaneUploadWizard class as follows;
public partial class TaskPaneUploadWizard : UserControl
{
...
public TaskPaneUploadWizard()
{
InitializeComponent();
}
private void TaskPaneUploadWizard_VisibleChanged(object sender, EventArgs e)
{
// Some code
}
My thoughts
It seems to me as though I am either attaching the eventHandler to something other than the CustomTaskPane object, or I am attaching it before the CustomTaskPane is created.
Help!

To detect if the task pane was opened or closed, you have to attach to the VisibleChanged event of pane.
So the simplest solution would be to add just one line of code to the GetTaskPane method:
var pane = Globals.ThisAddIn.CustomTaskPanes.Add(customTaskPane, taskPaneTitle);
// This is the new line to be added.
pane.VisibleChanged += (s, e) => customTaskPane.Visible = pane.Visible;
_createdPanes[key] = pane;
Now the visibility of the whole task pane will be passed on to its content and // some code should be executed.
Alternatively, if you don't want to manually set customTaskPane.Visible for whatever reason, you could as well execute your code directly in this new event handler:
pane.VisibleChanged += (s, e) => { /* some code */ };
But personally I would rather recommend the first approach because it seems to fit a bit better into your existing code.

var UploadWizardTaskpane = TaskPaneManager.GetTaskPane(title, title, () => new TaskPaneUploadWizard());
This is creating a CustomTaskPane not a TaskPaneUploadWizard object
It seems like this.VisibleChanged += new System.EventHandler(this.TaskPaneUploadWizard_VisibleChanged); is acting on TaskPaneUploadWizard which is only the guest of CustomTaskPane
Note that The visibility of CustomTaskPane doesn't affect TaskPaneUploadWizard
My suggestion
You remove VisibleChanged from the designer, you will add it manually in your TaskPaneUploadWizard
public partial class TaskPaneUploadWizard : UserControl
{
//{---}
CustomTaskPane _HostPane;
public CustomTaskPane HostPane
{
get => _HostPane;
set
{
if(_HostPane == value)
return;
_HostPane?.VisibleChanged -= TaskPaneUploadWizard_VisibleChanged;
_HostPane = value;
_HostPane?.VisibleChanged += TaskPaneUploadWizard_VisibleChanged;
}
}
//{---}
private void TaskPaneUploadWizard_VisibleChanged(object sender, EventArgs e)
{
// Some code
}
//{---}
Then in GetTaskPane you say
//{---}
var pane = Globals.ThisAddIn.CustomTaskPanes.Add(customTaskPane, taskPaneTitle);
(customTaskPane as TaskPaneUploadWizard).HostPane = pane;
//{---}

Cannot get rendered html via WebBrowser

I want to get html code from website. In Browser I usually can just click on ‘View Page Source’ in context menu or something similar. But how can I automatized it? I’ve tried it with WebBrowser class but sometimes it doesn’t work. I am not web developer so I don’t really know if my approach at least make sense. I think main problem is that I sometimes get html where not all code was executed. Hence it is uncompleted. I have problem with e.g. this site: http://www.sreality.cz/en/search/for-sale/praha
My code (I’ve tried to make it small but runnable on its own):
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace WebBrowserForm
{
internal static class Program
{
[STAThread]
private static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
for (int i = 0; i < 10; i++)
{
Form1 f = new Form1();
f.ShowDialog();
}
// Now I can check Form1.List and see that some html is final and some is not
}
}
public class Form1 : Form
{
public static List<string> List = new List<string>();
private const string Url = "http://www.sreality.cz/en/search/for-sale/praha";
private System.Windows.Forms.WebBrowser webBrowser1;
public Form1()
{
this.webBrowser1 = new System.Windows.Forms.WebBrowser();
this.SuspendLayout();
this.webBrowser1.Dock = System.Windows.Forms.DockStyle.Fill;
this.webBrowser1.Name = "webBrowser1";
this.webBrowser1.TabIndex = 0;
this.ResumeLayout(false);
Load += new EventHandler(Form1_Load);
this.webBrowser1.ObjectForScripting = new MyScript();
}
private void Form1_Load(object sender, EventArgs e)
{
webBrowser1.Navigate(Url);
webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(webBrowser1_DocumentCompleted);
}
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
if (webBrowser1.ReadyState == WebBrowserReadyState.Complete)
{
// Final html for 99% of web pages, but unfortunately not for all
string tst = webBrowser1.Document.GetElementsByTagName("HTML")[0].OuterHtml;
webBrowser1.DocumentCompleted -= new WebBrowserDocumentCompletedEventHandler(webBrowser1_DocumentCompleted);
Application.DoEvents();
webBrowser1.Navigate("javascript: window.external.CallServerSideCode();");
Application.DoEvents();
}
}
[ComVisible(true)]
public class MyScript
{
public void CallServerSideCode()
{
HtmlDocument doc = ((Form1)Application.OpenForms[0]).webBrowser1.Document;
string renderedHtml = doc.GetElementsByTagName("HTML")[0].OuterHtml;
// here I sometimes get full html but sometimes the same as in webBrowser1_DocumentCompleted method
List.Add(renderedHtml);
((Form1)Application.OpenForms[0]).Close();
}
}
}
}
I would expect that in ‘webBrowser1_DocumentCompleted’ method I could get final html. It usually works, but with this site it doesn’t. So I’ve tried get html in my own code which should be executed in web site -> method ‘CallServerSideCode’. What is strange that sometimes I get final html (basically the same as if I do it manually via Browser) but sometimes not. I think the problem is caused because my script start before whole web site is rendered instead after. But I am not really sure since this kind of things are far from my comfort zone and I don’t really understand what I am doing. I’m just trying to apply something what I found on the internet.
So, does anyone knows what is wrong with the code? Or even more importantly how to easily get final html from the site?
Any help appreciated.

You should use WebClient class to download HTML page. No display control necessary.
You want method DownloadString

May be it will be helpful if you add calling of your external function to the end of the body and wrap it by Jquery "ondomready" function. I mean something like this:
private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
if (webBrowser1.ReadyState == WebBrowserReadyState.Complete)
{
// Final html for 99% of web pages, but unfortunately not for all
string tst = webBrowser1.Document.GetElementsByTagName("HTML")[0].OuterHtml;
webBrowser1.DocumentCompleted -= new WebBrowserDocumentCompletedEventHandler(webBrowser1_DocumentCompleted);
HtmlElement body = webBrowser1.Document.GetElementsByTagName("body")[0];
HtmlElement scriptEl = webBrowser1.Document.CreateElement("script");
IHTMLScriptElement element = (IHTMLScriptElement)scriptEl.DomElement;
element.text = "$(function() { window.external.CallServerSideCode(); });";
body.AppendChild(scriptEl);
}
}
[ComVisible(true)]
public class MyScript
{
public void CallServerSideCode()
{
HtmlDocument doc = ((Form1)Application.OpenForms[0]).webBrowser1.Document;
string renderedHtml = doc.GetElementsByTagName("HTML")[0].OuterHtml;
// here I sometimes get full html but sometimes the same as in webBrowser1_DocumentCompleted method
List.Add(renderedHtml);
((Form1)Application.OpenForms[0]).Close();
}
}

Frame.Navigate in LoadState

I'm having trouble trying to navigate automatically between pages in my Windows 8.1 app based on a little check. It just doesn't want to navigate to another page when doing this in LoadState, as if something isn't loaded yet, but it doesn't give an error either. When I insert a delay using (for example) await Task.Delay(2000) before doing Frame.Navigate, then my app will redirect without any problem.
protected async override void LoadState(Object navigationParameter, Dictionary<String, Object> pageState)
{
MyData oData = await getData();
if (oData != null)
{
this.Frame.Navigate(typeof(newPage), oData);
}
else
{
// do something else
}
}
Do I have to put this code in another load- or navigated-event? Or how can I make this work?

In LoadState and SaveState you should only save and restore the page state (called when suspending and reactivating the app). Do nothing else (like navigating).
Put your logic into the OnNavigatedTo method instead...

If you want to navigate from method that called when page is loads, you should place your navigation code to OnNavigatedTo(...). But do not forget to wrap your code in Dispatcher.RunAsync(...) - Frame navigation in xaml return false

I tried calling Frame.Navigate(...) from the OnNavigatedTo method but still the navigation didn't occur.
There are other answers which say use Dispatcher.RunAsync, but that feels like it's making assumptions about the threading model of Windows Phone.
Here's what I do: attach a handler to the Loaded event of the page instead, and put my "redirect" logic in there. Loaded fires after OnNavigateTo and after NavigationHelper_LoadState, but before the page has become visible.
public LaunchPadPage() {
this.InitializeComponent();
this.navigationHelper = new NavigationHelper(this);
this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
this.navigationHelper.SaveState += this.NavigationHelper_SaveState;
this.Loaded += LaunchPadPage_Loaded;
this.app = (App)App.Current;
}
private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e) {
// Let's show the root zone items
// NB: In case we don't have this data yet, do nothing
if (app.Hierarchy != null)
{
DefaultViewModel["Items"] = app.Hierarchy.RootItems;
}
}
private void LaunchPadPage_Loaded(object sender, RoutedEventArgs e) {
// No data? Go to the downloads page instead.
if (app.Hierarchy == null)
{
Frame.Navigate(typeof(DownloadingPage));
}
}

HttpModule - get HTML content or controls for modifications

Tried something like this:
HttpApplication app = s as HttpApplication; //s is sender of the OnBeginRequest event
System.Web.UI.Page p = (System.Web.UI.Page)app.Context.Handler;
System.Web.UI.WebControls.Label lbl = new System.Web.UI.WebControls.Label();
lbl.Text = "TEST TEST TEST";
p.Controls.Add(lbl);
when running this I get "Object reference not set to an instance of an object." for the last line...
How do I get to insert two lines of text (asp.net/html) at specific loactions in the original file?
And how do I figure out the extension of the file (I only want to apply this on aspx files...?

Its simplier than you think:
public void Init(HttpApplication app)
{
app.PreRequestHandlerExecute += OnPreRequestHandlerExecute;
}
private void OnPreRequestHandlerExecute(object sender, EventArgs args)
{
HttpApplication app = sender as HttpApplication;
if (app != null)
{
Page page = app.Context.Handler as Page;
if (page != null)
{
page.PreRender += OnPreRender;
}
}
}
private void OnPreRender(object sender, EventArgs args)
{
Page page = sender as Page;
if (page != null)
{
page.Controls.Clear(); // Or do whatever u want with ur page...
}
}
If the PreRender Event isn't sufficient u can add whatever Event u need in the PreRequestHandlerExecute EventHandler...

I'm not sure, but I don't think you can use an HttpModule to alter the Page's control tree (please correct me if I'm wrong). You CAN modify the HTML markup however, you'll have to write a "response filter" for this. For an example, see http://aspnetresources.com/articles/HttpFilters.aspx, or google for "httpmodule response filter".

It seems like the HttpFilter solution is doing the trick here :o)
If I had used MOSS/.net 2.x+ I could have used Runes version or just added my tags in a master page...
Super suggestions and after my test of the solution, I'll accept miies.myopenid.com's solution as it seems to solve thar actual issue

There have been some changes in how you write HttpModules in IIS7 as compared to IIS6 or 5, so it might be that my suggestion is not valid if you are using IIS7.
If you use the Current static property of the HttpContext you can get a reference to the current context. The HttpContext class has properties for both the Request (HttpRequest type) and the Response (HttpResponse) and depending on where which event you are handling (Application.EndRequest maybe?) you can perform various actions on these objects.
If you want to change the content of the page being delivered you will probably want to do this as late as possible so responding to the EndRequest event is probably the best place to do this.
Checking which file type that was requested can be done by checking the Request.Url property, maybe together with the System.IO.Path class. Try something like this:
string requestPath = HttpContext.Current.Request.Url.AbsolutePath;
string extension = System.IO.Path.GetExtension(requestPath);
bool isAspx = extension.Equals(".aspx");
Modifying the content is harder. You may be able to do it in one of the events of the Context object, but I am not sure.
One possible approach could be to write your own cusom Page derived class that would check for a value in the Context.Items collection. If this value was found you could add a Label to a PlaceHolder object and set the text of the label to whatever you wanted.
Something like this should work:
Add the following code to a HttpModule derived class:
public void Init(HttpApplication context)
{
context.BeginRequest += new EventHandler(BeginRequest);
}
void BeginRequest(object sender, EventArgs e)
{
HttpContext context = HttpContext.Current;
HttpRequest request = context.Request;
string requestPath = HttpContext.Current.Request.Url.AbsolutePath;
string extension = System.IO.Path.GetExtension(requestPath);
bool isAspx = extension.Equals(".aspx");
if (isAspx)
{
// Add whatever you need of custom logic for adding the content here
context.Items["custom"] = "anything here";
}
}
Then you add the following class to the App_Code folder:
public class CustomPage : System.Web.UI.Page
{
public CustomPage()
{ }
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
if (Context.Items["custom"] == null)
{
return;
}
PlaceHolder placeHolder = this.FindControl("pp") as PlaceHolder;
if (placeHolder == null)
{
return;
}
Label addedContent = new Label();
addedContent.Text = Context.Items["custom"].ToString();
placeHolder .Controls.Add(addedContent);
}
}
Then you you modify your pages like this:
public partial class _Default : CustomPage
Note that the inheritance is changed from System.Web.UI.Page to CustomPage.
And finally you add PlaceHolder objects to your aspx files wherever you want you custom content.