Re: Initialize control dropped on form? - C# Discussion Boards

Re: which dll need to be imported to customize PrintPreviewDialog

10-May-04 3:59

Did you read the documentation for the PrintPreviewDialog? It states right at the bottom: the System.Windows.Forms.dll assembly. Read the documentation to learn what you can override. You will need to use Reflection to change existing behavior for buttons and other controls, however. The PrintPreviewDialog extends Form and just hosts a PrintPreviewControl with some buttons and combo boxes. You might consider a similar approach which would be easier depending on how much you want to change.

Just extend the Form class and host an instance of the PrintPreviewControl. Add your own controls and behavior to the form.

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sachinkalse12-May-04 21:05

sachinkalse

12-May-04 21:05

Thanks for your valuable suggestion. I am using PrintPreviewControl to make customized dialog, but the problem is that, how to integrate vertical scroll bar with next/previous page in co-ordination with the present zoom status. please do suggest
regards

Re: which dll need to be imported to customize PrintPreviewDialog

Heath Stewart13-May-04 2:30

13-May-04 2:30

I suggest you look at how the PrintPreviewDialog works. Download something like .NET Reflector[^] and find the PrintPreviewDialog in the System.Windows.Forms assembly. Use the decompiler to see how it works.

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BeginInvoke

Hugo Hallman9-May-04 12:50

Hugo Hallman

9-May-04 12:50

I can't find the equivalent to PostMessage in Windows Forms. I'm currently using BeginInvoke, as it's much like it, but then I get memory leaks, since I ignore the AsyncResults. What should I do with them? Store them in a queue which I walk through later to see if the Completedflag is set and can then safelly call endinvoke?
Thanks in advance

Re: BeginInvoke

Heath Stewart10-May-04 3:57

10-May-04 3:57

You won't get memory leaks if you ignore AsyncResults. .NET is GC'd. More than likely you're not using Control.InvokeRequired and Control.Invoke to call methods and get/set properties on controls created in a different thread. This is a common problem. When you comunicate with a control that was created on a different thread (the UI thread), you must use the ISynchronizeInvoke impementation that every control inherits from Control. This makes sure that communciate with the control happens in the UI thread.

If you want PostMessage, why not just P/Invoke it? If you read the forms, we're continually telling people to P/Invoke SendMessage to send the message immediately, but P/Invoking PostMessage is really no different. It would just look like this:

[DllImport("user32.dll")]
private static extern bool PostMessage(
  IntPtr hWnd,
  [MarshalAs(UnmanagedType.U4)] int msg,
  IntPtr wParam,
  IntPtr lParam);

If you need to pass a struct or reference to a struct or something, instead of marshaling the struct yourself and passing it as an IntPtr, you could overload PostMessage like so:

[DllImport("user32.dll")]
private static extern bool PostMessage(
  IntPtr hWnd,
  [MarshalAs(UnmanagedType.U4)] int msg,
  int wParam, // DON'T NEED - SET TO 0
  ref LVITEM lvItem);

Of course, you'd need to declare a managed LVITEM struct (can be named whatever you like, though) that would marshal correctly.

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Re: BeginInvoke

Hugo Hallman10-May-04 5:29

Hugo Hallman

10-May-04 5:29

Thank you very much for your answer. Although I don't agree on your discussion, I'll use the code you gave me.
I tested calling BeginInvoke(Nada) a hundred thousand times and then GC.Collect(); The memory footprint after the collection was over a hundred megs. ??? And the reason I ask is that I do use BeginInvoke, but am not satisfied with it. And Invoke is no option since it causes deadlocks in my case. (The UI is updated from a background process.)

Re: BeginInvoke

Heath Stewart10-May-04 5:34

10-May-04 5:34

Doesn't really matter if you don't agree with me - it's documented in the .NET Framework SDK. I suppose, then, that you disagree with Microsoft.

I didn't say that ignoring the AsyncResults doesn't incur a certain performance hit with memory consumption, I said it didn't incur any memory leaks. There is a difference. The very fact that the GC was able to collect the unused references proves that the objects where indeed tracked. The GC would've collected them eventually.

Memory leaks are when memory is lost and unreferenced, so it cannot be freed again, like when a variable references an alloc'd region of memory which is not freed. Once that variable goes out of scope it's practically impossible to free that memory again.

The fact remains that calling methods or setting properties (often getting as well) on controls from a different thread may cause problems. This is what's documented well in the .NET Framework if you read the right topics. Sometimes things may work. Other times they may not. Often times it is certain functionality that doesn't work as expected. It call comes down to the synchronization of threads, like it or not.

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Email clients

wfe9-May-04 12:13

9-May-04 12:13

Hi,

I have two clients installed on my PC.

Q1: How do I test/investigate (generally) a workstation to find out what email clients are available on a PC ?

I have a Class called OutlookConnector.CS that I use to retrieve the emails from my Outlook Client.

Q2: Is there a similar class for Outlook Express ?

Thanks in advance ! Confused | :confused:

Dave Kreskowiak10-May-04 0:11

Dave Kreskowiak

10-May-04 0:11

wfe wrote:
How do I test/investigate (generally) a workstation to find out what email clients are available on a PC ?

Nothing in the Windows API will supply you with this info. You'll problably have to search through the installed applications list, looking for specific application names, or go through the registry, or just ask the user what they use.

wfe wrote:
Is there a similar class for Outlook Express ?

Don't know. What does this class do? Where did it come from? If the class you have is pretty general in nature, then the same class might work for Outlook Express since you programatically use both of them the same way.

RageInTheMachine9532

wfe10-May-04 1:17

10-May-04 1:17

Thanks Dave,

Q1a: How do I search 'installed applications list' on a local PC from C#/.NET ?

Q1b: How do I search the registry ?

If I ask the user for what they use, I still have the problem of addressing the mailboxes locally on Outlook Express. Also, I would like to learn the Windows API and general environment by making the application 'fool proof'.

I don't know where the class came from - probably a former colleaque of mine.

I have enclosed the class below.

Thanks for your help

William

<br />
using System;<br />
using System.Data;<br />
using System.Diagnostics;<br />
using System.Windows.Forms;<br />
<br />
namespace test<br />
{<br />
	/// <summary><br />
	/// Delegate declaration for each time an item is processed from an Outlook folder.<br />
	/// </summary><br />
	public delegate void OutlookItemProcessed();<br />
<br />
	/// <summary><br />
	/// This disposable class acts a translator for information stored in the user's Outlook folders.<br />
	/// </summary><br />
	public class OutlookConnector : IDisposable<br />
	{<br />
		private Outlook.Application objOutlook = null;<br />
		private Outlook.NameSpace objNamespace = null;<br />
		private Outlook.MAPIFolder objFolder = null;<br />
		private Outlook.Items objItems = null;<br />
		public event OutlookItemProcessed ItemProcessed;<br />
<br />
		public OutlookConnector()<br />
		{<br />
			objOutlook = new Outlook.ApplicationClass();<br />
			objNamespace = objOutlook.GetNamespace("MAPI");<br />
		}<br />
<br />
		/// <summary><br />
		/// Close the Outlook application when this instance is disposed.<br />
		/// </summary><br />
		public void Dispose()<br />
		{<br />
			if (objOutlook != null) objOutlook.Quit();<br />
		}<br />
<br />
		/// <summary><br />
		/// Get the number of items within the specified default Outlook folder.<br />
		/// </summary><br />
		/// <param name="folder">outlook folder enumerated value</param><br />
		/// <returns>total number of items</returns><br />
		public int getFolderCount(Outlook.OlDefaultFolders folder)<br />
		{<br />
			objFolder = objNamespace.GetDefaultFolder(folder);<br />
			return objFolder.Items.Count;<br />
		}<br />
<br />
		/// <summary><br />
		/// Retrieve a list of all appointments listed in the Outlook calendar.<br />
		/// </summary><br />
		/// <returns>Calendar Items DataSet</returns><br />
		public DataSet getCalendarDataSet()<br />
		{<br />
			Outlook.AppointmentItem item;<br />
			DataSet rv = new DataSet();<br />
			rv.DataSetName = "Calendar";<br />
			rv.Tables.Add("Appointment");<br />
			rv.Tables[0].Columns.Add("Subject");<br />
			rv.Tables[0].Columns.Add("Location");<br />
			rv.Tables[0].Columns.Add("Start");<br />
			rv.Tables[0].Columns.Add("End");<br />
			rv.Tables[0].Columns.Add("AllDayEvent");<br />
			rv.Tables[0].Columns.Add("Duration");<br />
			rv.Tables[0].Columns.Add("Organizer");<br />
			rv.Tables[0].Columns.Add("Importance");<br />
			rv.Tables[0].Columns.Add("Sensitivity");<br />
			rv.Tables[0].Columns.Add("Body");<br />
<br />
			try<br />
			{<br />
				objFolder = objNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderCalendar);<br />
				Debug.WriteLine(objFolder.Items.Count + " Appointments found.");<br />
				for (int i=0; i < objFolder.Items.Count; i++) <br />
				{<br />
					item = (Outlook.AppointmentItem)objFolder.Items.Item(i);<br />
					rv.Tables[0].Rows.Add(new object[] {<br />
						item.Subject,<br />
						item.Location,<br />
						item.Start,<br />
						item.End,<br />
						item.AllDayEvent,<br />
						item.Duration,<br />
						item.Organizer,<br />
						item.Importance,<br />
						item.Sensitivity,<br />
						item.Body<br />
					});<br />
					this.ItemProcessed();<br />
				}<br />
				Debug.WriteLine(rv.Tables[0].Rows.Count + " Appointments exported.");<br />
			}<br />
			catch (System.Exception e)<br />
			{<br />
				Console.WriteLine(e);<br />
			}<br />
			return rv;<br />
		}<br />
<br />
		/// <summary><br />
		/// Retrieves a list of all the Outlook Contacts.<br />
		/// </summary><br />
		/// <returns>Contact Items DataSet</returns><br />
		public DataSet getContactDataSet()<br />
		{<br />
			Outlook.ContactItem item;<br />
			DataSet rv = new DataSet();<br />
			rv.DataSetName = "Contacts";<br />
			rv.Tables.Add("Contact");<br />
			rv.Tables[0].Columns.Add("FirstName");<br />
			rv.Tables[0].Columns.Add("LastName");<br />
			rv.Tables[0].Columns.Add("CompanyName");<br />
			rv.Tables[0].Columns.Add("Email");<br />
			rv.Tables[0].Columns.Add("HomePhone");<br />
			rv.Tables[0].Columns.Add("WorkPhone");<br />
<br />
			try<br />
			{<br />
				objFolder = objNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderContacts);<br />
				Debug.WriteLine(objFolder.Items.Count + " Contacts found.");<br />
				for (int i=0; i < objFolder.Items.Count; i++) <br />
				{<br />
					item = (Outlook.ContactItem)objFolder.Items.Item(i);<br />
					rv.Tables[0].Rows.Add(new object[] {<br />
						item.FirstName,<br />
						item.LastName,<br />
						item.CompanyName,<br />
						item.Email1Address,<br />
						item.HomeTelephoneNumber,<br />
						item.BusinessTelephoneNumber<br />
					});<br />
					this.ItemProcessed();<br />
				}<br />
				Debug.WriteLine(rv.Tables[0].Rows.Count + " Contacts exported.");<br />
			}<br />
			catch (System.Exception e)<br />
			{<br />
				Console.WriteLine(e);<br />
			}<br />
			return rv;<br />
		}<br />
<br />
		/// <summary><br />
		/// Retrieves a list of all emails in the Outlook Inbox.<br />
		/// </summary><br />
		/// <returns>Inbox E-Mail Items DataSet</returns><br />
		public DataSet getInboxDataSet()<br />
		{<br />
			Outlook.MailItem item;<br />
			DataSet rv = new DataSet();<br />
			rv.DataSetName = "InboxEmails";<br />
			rv.Tables.Add("Email");<br />
			rv.Tables[0].Columns.Add("Name");<br />
			rv.Tables[0].Columns.Add("To");<br />
			rv.Tables[0].Columns.Add("Cc");<br />
			rv.Tables[0].Columns.Add("Subject");<br />
			rv.Tables[0].Columns.Add("Received");<br />
			rv.Tables[0].Columns.Add("Message");<br />
<br />
<br />
			try<br />
			{<br />
				objFolder = objNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderInbox);	<br />
				objItems = objFolder.Items.Restrict("[MessageClass]='IPM.Note'");<br />
<br />
				///strFind = "[Start] <= """ & FormatDateTime(currentDate,  vbShortDate)<br />
<br />
				Debug.WriteLine(objItems.Count + " E-Mails found.");<br />
				for (int i=1; i <= objItems.Count; i++) <br />
				{<br />
					item = (Outlook.MailItem)objItems.Item(i);				<br />
					{<br />
						rv.Tables[0].Rows.Add(new object[] {<br />
															   item.SenderName,<br />
															   item.To,<br />
															   item.CC,<br />
															   item.Subject,<br />
															   item.ReceivedTime,<br />
															   item.Body<br />
														   });<br />
	<br />
					}<br />
					this.ItemProcessed();<br />
				}<br />
				Debug.WriteLine(rv.Tables[0].Rows.Count + " E-Mails exported.");<br />
<br />
			}<br />
			catch (System.Exception e)<br />
			{<br />
				Console.WriteLine(e);<br />
			}<br />
			return rv;<br />
		}<br />
<br />
		/// <summary><br />
		/// Retrieves a list of all Outlook Notes.<br />
		/// </summary><br />
		/// <returns>Note Items DataSet</returns><br />
		public DataSet getNoteDataSet()<br />
		{<br />
			Outlook.NoteItem item;<br />
			DataSet rv = new DataSet();<br />
			rv.DataSetName = "Notes";<br />
			rv.Tables.Add("Note");<br />
			rv.Tables[0].Columns.Add("Subject");<br />
			rv.Tables[0].Columns.Add("Categories");<br />
			rv.Tables[0].Columns.Add("CreationTime");<br />
			rv.Tables[0].Columns.Add("LastModificationTime");<br />
			rv.Tables[0].Columns.Add("Contents");<br />
<br />
			try<br />
			{<br />
				objFolder = objNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderNotes);<br />
				Debug.WriteLine(objFolder.Items.Count + " Notes found.");<br />
				for (int i=0; i < objFolder.Items.Count; i++) <br />
				{<br />
					item = (Outlook.NoteItem)objFolder.Items.Item(i);<br />
					rv.Tables[0].Rows.Add(new object[] {<br />
						item.Subject,<br />
						item.Categories,<br />
						item.CreationTime,<br />
						item.LastModificationTime,<br />
						item.Body<br />
					});<br />
					this.ItemProcessed();<br />
				}<br />
				Debug.WriteLine(rv.Tables[0].Rows.Count + " Notes exported.");<br />
			}<br />
			catch (System.Exception e)<br />
			{<br />
				Console.WriteLine(e);<br />
			}<br />
			return rv;<br />
		}<br />
<br />
		/// <summary><br />
		/// Retrieves a list of all Outlook Tasks.<br />
		/// </summary><br />
		/// <returns>Task Items DataSet</returns><br />
		public DataSet getTaskDataSet()<br />
		{<br />
			Outlook.TaskItem item;<br />
			DataSet rv = new DataSet();<br />
			rv.DataSetName = "Tasks";<br />
			rv.Tables.Add("Task");<br />
			rv.Tables[0].Columns.Add("Subject");<br />
			rv.Tables[0].Columns.Add("StartDate");<br />
			rv.Tables[0].Columns.Add("DueDate");<br />
			rv.Tables[0].Columns.Add("Status");<br />
			rv.Tables[0].Columns.Add("Contents");<br />
<br />
			try<br />
			{<br />
				objFolder = objNamespace.GetDefaultFolder(Outlook.OlDefaultFolders.olFolderTasks);<br />
				Debug.WriteLine(objFolder.Items.Count + " Tasks found.");<br />
				for (int i=0; i < objFolder.Items.Count; i++) <br />
				{<br />
					item = (Outlook.TaskItem)objFolder.Items.Item(i);<br />
					rv.Tables[0].Rows.Add(new object[] {<br />
						item.Subject,<br />
						item.StartDate,<br />
						item.DueDate,<br />
						item.Status,<br />
						item.Body<br />
					});<br />
					this.ItemProcessed();<br />
				}<br />
				Debug.WriteLine(rv.Tables[0].Rows.Count + " Tasks exported.");<br />
			}<br />
			catch (System.Exception e)<br />
			{<br />
				Console.WriteLine(e);<br />
			}<br />
			return rv;<br />
		}<br />
	}<br />
}<br />
<br />

Heath Stewart10-May-04 3:49

10-May-04 3:49

wfe wrote:
Q1a: How do I search 'installed applications list' on a local PC from C#/.NET ?

The easiest way is using WMI. See the System.Management namespace in the clas library documentation of the .NET Framework SDK. Make a request on the remote machine (or even your local machine, which you can refer to as "." or just don't specify a machine at all) for the Win32_Product CIMv2 class.

See System.Management Lets You Take Advantage of WMI APIs within Managed Code[^] in MSDN Magazine online for more information, sample code, and a link to an add-in for VS.NET 2002 (and if you search, for 2003) that lets you browse the WMI repository on any machine and to create managed wrapper classes just by dragging and dropping classes into your project.

wfe wrote:
Q1b: How do I search the registry ?

The .NET FCL (Framework Class Library) does not let you access the registry of a remote machine. You either need to P/Invoke the registry APIs yourself or find a project that already does this for you. I'd recommend the method above, though, since it's far more robust and less error-prone (messing with the registry is dangerous, especially if you don't know what you're doing).

As far as the connector goes, both Outlook and Outlook Express are MAPI clients so you can use MAPI wrappers, like Simple MAPI.NET[^]. There are many restrictions in the MAPI implementations these days, however, because of script kiddies (responsible for all those malicious worms you hear about). The basic stuff should work fine, however, like sending a mail message. Accessing the address book using MAPI (which is scriptable, where Extended MAPI is not) will either fail or prompt the user that some program is trying to access their address book and prompt them to allow it and for how long, or to simply deny the request. There is plenty of documentation about this subject online. Just google for MAPI or something and you'll find a lot of information. Another good place is to search on MSDN[^].

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wfe10-May-04 7:59

10-May-04 7:59

Thanks for your reply.

I know your intentions are good but I am not getting much help from this.

All I need is a SPECIFIC and CONCRETE code description, not references to millions of linked articles that I do not yet understand as I am not yet familiar with the underlying development environment under Windows.

Heath Stewart wrote:
Make a request on the remote machine (or even your local machine, which you can refer to as "." or just don't specify a machine at all) for the Win32_Product CIMv2 class.

Q1: How do I 'make a request' ? I have read your references in the SDK but cannot find anything relating to Win32_Product class. All I get is a list of classes, delegates and enumerations ?

Please, can you provide specific help ?

Heath Stewart wrote:
As far as the connector goes, both Outlook and Outlook Express are MAPI clients so you can use MAPI wrappers

Q2: Good, then why does it pick the emails from Outlook and not from Outlook Express and how do I change it ?

Thanks (and sorry for the panic !)

William

Heath Stewart10-May-04 8:58

10-May-04 8:58

That's the point - learn. Read the article I linked, which shows how to make a request. The Win32_Product is not a .NET class, but a WMI CIMv2 class. If you read the article, it shows you how to make a query (albeit against a different WMI class).

The default MAPI client is used when you make calls to MAPI. This can be changed in WinXP through the Start properties. MAPI clients like Outlook, Outlook Express, Mozilla Mail, etc. also typically have a setting in their preference to make that application the default MAPI client. You as a developer should not change this. Only the user should make that change.

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wfe10-May-04 9:23

10-May-04 9:23

Don't get me wrong - I am learning. But I keep being sent of on tangents that make me spend a lot more time than necessary to get minor obstacles out of the way for achieving my goals.

Right now, for instance, I am spending my second day on finding out what concepts like WMI, CIM etc. REALLY mean and whether they are important at all for anyone outside the 'nerd community' (excuse the expression it is not meant for you).

I also think it is an extremely inefficient way of learning when you have to guess 90% of the idea behind an answer and not even be able to do that before reading (a range of) articles that also do not provide the answer specifically.

I usually learn the other way around - by extrapolation: I ask a specific question, get a specific answer and then work my way out from there by investigating what other methods in the same class do and what other classes in the same namespace do. I relate.

On the MAPI client question: The default client for email is Outlook Express, but the class picks up contents from the Outlook Inbox folder locally and NOT the Outlook Express folder.

The point of my excersise is not to change anything on the users behalf but to be able to know what is going on in the application.

I do hope you can help.

In the meantime, I shall return to my lair and devote myself to studying.

Best regards

William

Heath Stewart10-May-04 9:43

10-May-04 9:43

Did you actually read the article? Understanding WMI is simple: it's script-based access to information on remote machines. You don't have to understand CIM, which is like WMI standard classes.

A simple way to query a remote client for products is like so:

public void EnumProducts(string machine)
{
  string scope = "root\\cimv2";
  if (machine != null && machine.Length > 0) scope = string.Format(
    "\\\\{0}\\{1}", machine, scope);
  ManagementObjectSearcher searcher = new ManagementObjectSearcher(
    scope,
    "SELECT * FROM Win32_Product");
  ManagementObjectCollection products = searcher.Get();
  foreach (ManagementObject product in products)
    Console.WriteLine(product["Name"]);
}

Note that this will only enumerator products installed via Windows Installer.

If you read the article, you'll see a link to a VS.NET add-in that creates a typed class for the Win32_Product class (or whatever class you use). This makes it much easier to use and enumerate.

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wfe11-May-04 3:00