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Andres Jaimes

C# Tips and Tricks

By Andres Jaimes

Reading Outlook Contacts

Have you ever realized all you can do if Outlook contacts information were located into a database? If you have, this tip is for you. The first step is to take all that information out from Outlook so we can transform it into series of insert/update statements.

Start Microsoft Visual C# Express (you can download it for free from Microsoft’s site pending link).
Once downloaded and installed, create a new project and add Outlook’s library to it:
Go to Project -> Add Reference -> COM and select Microsoft Outlook 11.0 Object Library

Outlook Library

Add the following line to the beginning of the file:

using Outlook;

Update:

Last time I did it I had to change last line to this:

using Outlook = Microsoft.Office.Interop.Outlook;

And here’s the code:

Outlook.Application app = new ApplicationClass();
Outlook.NameSpace ns = app.GetNamespace("MAPI");
ns.Logon("outlook-username", "outlook-password", false, true);

MAPIFolder apf;
MAPIFolder contacts;
string storeId;

apf = ns.GetDefaultFolder(
    OlDefaultFolders.olPublicFoldersAllPublicFolders);
contacts = apf.Folders["your-public-folder-name"];

storeId = contacts.StoreID;

foreach (Object o in contacts.Items){ 
    // Casting is important to avoid any distribution list
    if (o is ContactItem)
    {
        ContactItem c = (ContactItem)o;
        Console.Writeline(c.LastName + "n");
    }
}
ns.Logoff();

Ok, we now know how to access and loop contacts, the missing thing is how to save them in an external database.
By the way, the ns.Logon function receives four parameters:

  1. string Profile: that’s your username,
  2. string Password: that’s your username,
  3. bool ShowDialog: that’s your username and
  4. bool NewSession: that’s your username

If the contact list you’re trying to access is not in the root level, but is a subfolder inside a subfolder inside a subfolder… like in the following image:

Outlook subfolders

then this is the way you should go:

apf = ns.GetDefaultFolder(
    OlDefaultFolders.olPublicFoldersAllPublicFolders);
contacts =
    apf.Folders["International"].Folders["MX"].Folders["Admin Contacts"];

Sending mail from C#

An easy way to send email using C#:

System.Net.Mail.MailMessage message =
    new System.Net.Mail.MailMessage();
message.To.Add("luckyperson@online.microsoft.com");
message.Subject = "This is the Subject line";
message.From =
    new System.Net.Mail.MailAddress("from@online.microsoft.com");
message.Body = "This is the message body";
System.Net.Mail.SmtpClient smtp =
    new System.Net.Mail.SmtpClient("yoursmtphost");
smtp.Send(message);

source: http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=717&SiteID=1

System.Transactions

If you want to use System.Transactions in your application,

  1. Right click project name in Solution Explorer and click Add a Reference…
  2. In the .NET tab find and select the System.Transactions option
  3. Click Ok and enjoy.

If you don’t add the reference you will get the following error while compiling:

The type or namespace name ‘Transactions’ does not exist in the namespace ‘System’ (are you missing an assembly reference?)

Creating a message box

Well, it is very simple…

MessageBox.Show("Your message")

There are many available options… be sure you take a look at them.

Getting the Windows user name, domain, etc…

There are two ways to accomplish this, first the short way:

Environment.UserName // user
Environment.UserDomainName // domain

And the long way:

System.Security.Principal.WindowsIdentity.GetCurrent().Name.ToString();

The long way will give you access to many more options so be sure to explore it.

How to read a text file

Add the following code at the beginning of your file:

Using System.IO;

And here’s the code…

String text;
try {
  StreamReader sr = new StreamReader("C:file.txt");
  text = sr.ReadLine();
  while (text != null) {
    Console.WriteLine(text);
    text = sr.ReadLine();
  }
  sr.Close();
  Console.ReadLine();
}
catch(Exception ex) {
  Console.WriteLine("Exception: " + ex.Message);
}

How to write a text file

Add the following code at the beginning of your file:

Using System.IO;

And here it goes…

try {
  StreamWriter sw = new StreamWriter("C:file.txt");
  sw.WriteLine("Hello World!!!");
  sw.WriteLine("This is a test");
  sw.Close();
}
catch(Exception e) {
  Console.WriteLine("Exception: " + e.Message);
}

How to connect to Access

Code:

using System.Data.OleDb;
...

OleDbConnection conn = new OleDbConnection(
    "Provider=Microsoft.Jet.OLEDB.4.0;" +
    "Data Source=C:database.mdb;" +
    "Jet OLEDB:Database Password=password");
conn.Open();

OleDbCommand cmd =  new OleDbCommand("select * from mytable", conn);
OleDbDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
    Console.WriteLine(dr.GetString(0));
}
conn.Close();

How to connect to MySQL

See my MySQL section.

Error: IErrorInfo.GetDescription Failed with E_FAIL(0x80004005)

When you are querying a database you get this error. The reason is your query is using a keyword for a column name, table, etc. It does not matter if your query works well when you execute it directly in your database manager, remember there are more layers between C# and your database.

Data Types for C# and MSAccess 2002

If you want to do a “perfect” match between data types in MSAccess and C#
C# data types

<th>
  CLR
</th>

<th>
  Signed
</th>

<th>
  Memory
</th>

<th>
  Range
</th>

<td>
  System.Sbyte
</td>

<td>
  Yes
</td>

<td>
  1 byte
</td>

<td>
  €“128 to 127
</td>

<td>
  System.Byte
</td>

<td>
  No
</td>

<td>
  1 byte
</td>

<td>
  0 to 255
</td>

<td>
  System.Int16
</td>

<td>
  Yes
</td>

<td>
  2 bytes
</td>

<td>
  32768 to 32767
</td>

<td>
  System.Int32
</td>

<td>
  Yes
</td>

<td>
  4 bytes
</td>

<td>
  2147483648 to 2147483647
</td>

<td>
  System.Int64
</td>

<td>
  Yes
</td>

<td>
  8 bytes
</td>

<td>
  9223372036854775808 to 9223372036854775807
</td>

<td>
  System.Uint16
</td>

<td>
  No
</td>

<td>
  2 bytes
</td>

<td>
  0 to 65535
</td>

<td>
  System.Uint32
</td>

<td>
  No
</td>

<td>
  4 bytes
</td>

<td>
  0 to 4294967295
</td>

<td>
  System.Uint64
</td>

<td>
  No
</td>

<td>
  8 bytes
</td>

<td>
  0 to 18446744073709551615
</td>

<td>
  System.Single
</td>

<td>
  Yes
</td>

<td>
  4 bytes
</td>

<td>
  1.5&#215;10-45 to 3.4 x x1038
</td>

<td>
  System.Double
</td>

<td>
  Yes
</td>

<td>
  8 bytes
</td>

<td>
  5.0&#215;10-324 to 1.7&#215;10308
</td>

<td>
  System.Decimal
</td>

<td>
  Yes
</td>

<td>
  12 bytes
</td>

<td>
  1.0&#215;10-28 to 7.9&#215;1028
</td>

<td>
  System.Char
</td>

<td>
   
</td>

<td>
  2 bytes
</td>

<td>
  Unicode characters
</td>

<td>
  System.Boolean
</td>

<td>
   
</td>

<td>
  1 byte
</td>

<td>
  True or false
</td>

MS Access data types

<th>
  Range
</th>

<th>
  Decimal precision
</th>

<th>
  Memory
</th>

<td>
  0 to 255 (no fractions)
</td>

<td>
  None
</td>

<td>
  1 byte
</td>

<td>
  10^38-1 through 10^38-1 (.adp)<br /> -10^28-1 through 10^28-1 (.mdb)
</td>

<td>
  28
</td>

<td>
  12bytes
</td>

<td>
  -32768 to 32767 (no fractions).
</td>

<td>
  None
</td>

<td>
  2 bytes
</td>

<td>
  (Default) -2147483648 to 2147483647 (no fractions).
</td>

<td>
  None
</td>

<td>
  4 bytes
</td>

<td>
  -3.402823E38 to -1.401298E-45 for negative values and<br /> 1.401298E-45 to 3.402823E38 for positive values.
</td>

<td>
  7
</td>

<td>
  4 bytes
</td>

<td>
  -1.79769313486231E308 to<br /> -4.94065645841247E€“324 for negative values and<br /> 4.94065645841247E-324 to<br /> 1.79769313486231E308 for positive values.
</td>

<td>
  15
</td>

<td>
  8 bytes
</td>

<td>
  Globally unique identifier (GUID)
</td>

<td>
  N/A
</td>

<td>
  16 bytes
</td>