ch9.htm

MAPI__SAPI__TAPI

  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ReadInbox <br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Case 5 ' send mail<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SendMail <br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Case 6 ' read &amp; send<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ReadInbox <br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SendMail <br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Case 7 ' exit <br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Unload Me<br>
  &nbsp;&nbsp;&nbsp;&nbsp;End Select<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  End Sub</font></tt> </p>
</blockquote>

<hr>

<p>One more line of code is needed to complete this section. The text box control should 
be a read-only form object. By adding the following line of code to the <tt><font
FACE="Courier">Text1_KeyPress</font></tt> event, you can trick Visual Basic into ignoring 
any keyboard input performed within the text box control. </p>

<blockquote>
  <tt><font FACE="Courier"><p>Private Sub Text1_KeyPress(KeyAscii As Integer)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;KeyAscii = 0<br>
  End Sub</font></tt> </p>
</blockquote>

<p>That's the code needed to support form events and controls. Save this form as <tt><font
FACE="Courier">MLM.FRM</font></tt> and save the project as <tt><font FACE="Courier">MLM.VBP</font></tt>. 
In the next section you'll add a series of simple support routines to the project. </p>

<h3><a NAME="CodingtheSupportRoutines"><b>Coding the Support Routines</b></a> </h3>

<p>Now you'll add a few support routines that are called frequently from other, high-level 
routines in the project. You'll add all these routines to the general declaration section 
of the form. </p>

<p>First, add a new subroutine called <tt><font FACE="Courier">Status</font></tt>, and add 
the code shown in Listing 9.5. </p>

<hr>

<blockquote>
  <b><p>Listing 9.5. Adding the <tt><font FACE="Courier">Status</font></tt> routine to the 
  project.<br>
  </b></p>
</blockquote>

<blockquote>
  <tt><font FACE="Courier"><p>Public Sub Status(cInfo As String)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;' send info to status line<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;If cInfo = &quot;&quot; Then<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Text1 = &quot;&quot; <br>
  &nbsp;&nbsp;&nbsp;&nbsp;Else<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Text1 = Text1 &amp; cInfo &amp; Chr(13) 
  &amp; Chr(10)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;End If<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  End Sub</font></tt> </p>
</blockquote>

<hr>

<p>The code in the <tt><font FACE="Courier">Status</font></tt> routine places a new line 
in the text box. This will be used to pass progress information to the text box control as 
the MLM is processing subscriber lists and the Microsoft Exchange inbox. </p>

<p>The MLM project gets its primary instructions from a set of ASCII text control files. 
The next routine you'll build in this section is the one that reads the master control 
file. Add a new subroutine called <tt><font FACE="Courier">ControlsLoad</font></tt> to the 
project, and enter the code shown in Listing 9.6. </p>

<hr>

<blockquote>
  <b><p>Listing 9.6. Adding the <tt><font FACE="Courier">ControlsLoad</font></tt> routine.<br>
  </b></p>
</blockquote>

<blockquote>
  <tt><font FACE="Courier"><p>Public Sub ControlsLoad()<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;' load control values into variables<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;On Error GoTo ControlsLoadErr<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Status &quot;&quot;<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Status &quot;Loading Control Values...&quot; <br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim nFile As Integer<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim nCount As Integer<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim cLine As String<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim nPos As Integer<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;bErr = False<br>
  &nbsp;&nbsp;&nbsp;&nbsp;nCount = 0<br>
  &nbsp;&nbsp;&nbsp;&nbsp;nFile = FreeFile<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Open cMLMFile For Input As nFile<br>
  &nbsp;&nbsp;&nbsp;&nbsp;While Not EOF(nFile)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Line Input #nFile, cLine<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If Left(cLine, 1) &lt;&gt; &quot;;&quot; 
  Then<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nPos = 
  InStr(cLine, &quot;=&quot;)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If nPos &lt;&gt; 0 
  Then<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nCount 
  = nCount + 1<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ReDim 
  Preserve cCtlName(nCount)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ReDim 
  Preserve cCtlValue(nCount)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cCtlName(nCount) 
  = Left(cLine, nPos - 1)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cCtlValue(nCount) 
  = Mid(cLine, nPos + 1, 255)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;End If<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;End If<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Wend<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Close #nFile<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Exit Sub<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  ControlsLoadErr:<br>
  &nbsp;&nbsp;&nbsp;&nbsp;MsgBox Error$, vbCritical, &quot;ControlsLoad Error [&quot; &amp; 
  CStr(Err) &amp; &quot;]&quot;<br>
  &nbsp;&nbsp;&nbsp;&nbsp;bErr = True<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  End Sub</font></tt> </p>
</blockquote>

<hr>

<p>Notice that the <tt><font FACE="Courier">ControlsLoad</font></tt> routine reads each 
line of the ASCII text file, and if it is not a comment line (that is, it starts with a 
&quot;;&quot;), it parses the line into a control name array and a control value array. 
You'll use these values throughout your project. </p>

<p>Now that the control values are stored in a local array, you need a routine to retrieve 
a particular control value. Add a new function (not a subroutine) to the project called <tt><font
FACE="Courier">ControlSetting</font></tt>, and add the code shown in Listing 9.7. </p>

<hr>

<blockquote>
  <b><p>Listing 9.7. Adding the <tt><font FACE="Courier">ControlSetting</font></tt> 
  function.<br>
  </b></p>
</blockquote>

<blockquote>
  <tt><font FACE="Courier"><p>Public Function ControlSetting(cName As String) As String<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;' look up control setting<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim cReturn As String<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim nCount As Integer<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim x As Integer<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;nCount = UBound(cCtlName)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;cName = UCase(cName)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;For x = 1 To nCount<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If cName = UCase(cCtlName(x)) Then<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cReturn = 
  cCtlValue(x)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Exit For<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;End If<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Next x<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;ControlSetting = cReturn<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  End Function</font></tt> </p>
</blockquote>

<hr>

<p>The <tt><font FACE="Courier">ControlSetting</font></tt> function accepts a single 
parameter (the name of the control value you are requesting) and returns a single value 
(the value of the control setting you named). This routine accomplishes its task by simply 
reading through the array of control names until the name is found. </p>

<p>That's all for the general support routines. Save this form and project again before 
continuing. </p>

<h3><a NAME="CodingtheEditRoutines"><b>Coding the Edit Routines</b></a> </h3>

<p>This next set of routines allows users to edit the various control files required to 
manage the project. You'll use a call to the <tt><font FACE="Courier">NOTEPAD.EXE</font></tt> 
applet to edit the control files. This is much easier than spending the time to write your 
own text file editor. Also, the first time you call these routines you'll be prompted to 
create the new files. </p>

<p>Add a new subroutine called <tt><font FACE="Courier">ControlsEdit</font></tt> to the 
form, and enter the code shown in Listing 9.8. </p>

<hr>

<blockquote>
  <b><p>Listing 9.8. Adding the <tt><font FACE="Courier">ControlsEdit</font></tt> routine.<br>
  </b></p>
</blockquote>

<blockquote>
  <tt><font FACE="Courier"><p>Public Sub ControlsEdit()<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim rtn As Long<br>
  &nbsp;&nbsp;&nbsp;&nbsp;Dim cEditor<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;ControlsLoad<br>
  &nbsp;&nbsp;&nbsp;&nbsp;If bErr &lt;&gt; True Then<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cEditor = 
  ControlSetting(&quot;Editor&quot;) <br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Status &quot;Opening Control File [&quot; 
  &amp; cMLMFile &amp; &quot;]...&quot;<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;rtn = Shell(cEditor &amp; &quot; &quot; 
  &amp; cMLMFile, 1)<br>
  &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Status &quot;Closing Control File...&quot;<br>
  &nbsp;&nbsp;&nbsp;&nbsp;End If<br>
  &nbsp;&nbsp;&nbsp;&nbsp;'<br>
  End Sub</font></tt> </p>
</blockquote>

<hr>

<p>This routine first attempts to load the master control values, then launches the 
default editor to allow users to modify those values. You can also see the use of the <tt><font
FACE="Courier">Status</font></tt> routine to update the form's text box. Go back to the <tt><font
FACE="Courier">Command1_Click</font></tt> routine (see Listing 9.4) and remove the comment 
from in front of the <tt><font FACE="Courier">ControlsLoad</font></tt> command. Then save 
this project. </p>

<p>Before you can run this routine, you need to create the default control file. Start <tt><font
FACE="Courier">NOTEPAD.EXE</font></tt> and enter the information shown in Listing 9.9. 
Once you complete the entry, save the file in the same folder as the MLM project and call 
it <tt><font FACE="Courier">MLM.TXT</font></tt>. </p>
<div align="center"><center>

<table BORDERCOLOR="#000000" BORDER="1" WIDTH="80%">
  <tr>
    <td><b>Tip</b></td>
  </tr>
  <tr>
    <td><blockquote>
      <p>If you get errors attempting to launch the editor from these routines, you can include 
      the drive and path qualifiers in the <tt><font FACE="Courier">Editor</font></tt> control 
      value. </p>
    </blockquote>
    </td>
  </tr>
</table>
</center></div>

<hr>

<blockquote>
  <b><p>Listing 9.9. Creating the default <tt><font FACE="Courier">MLM.TXT</font></tt> 
  control file.<br>
  </b></p>
</blockquote>

<blockquote>
  <tt><font FACE="Courier"><p>;&nbsp;=================================================== <br>
  ;&nbsp;Mailing List Control values for MLM<br>
  ;&nbsp;===================================================<br>
  ;<br>
  ;&nbsp;read by MLM.EXE<br>
  ;<br>
  ;&nbsp;===================================================<br>
  ;<br>
  MAPIUserName=MCA<br>
  MAPIPassword=<br>
  SearchKey=MLM<br>
  ListName=MLM Mailing List<br>
  NewSub=SUB<br>
  NewSubMsg=MLMHello.txt<br>
  UnSubMsg=MLMBye.txt<br>
  UnSub=UNSUB<br>
  GetArchive=GET<br>
  ListArchive=LIST<br>
  ArchiveFile=MLMArch.txt<br>
  ListSchedule=MLMSked.txt<br>
  ListSubs=MLMSubs.txt<br>
  Editor=notepad.exe</font></tt> </p>
</blockquote>
<div align="center"><center>

<table BORDERCOLOR="#000000" BORDER="1" WIDTH="80%">
  <tr>
    <td><b>Tip</b></td>
  </tr>
  <tr>
    <td><blockquote>
      <p>If you don't want to spend time entering this control file information, you can find it 
      in the MLM folder that was created when you installed the source code from the CD-ROM.</p>
    </blockquote>
    </td>
  </tr>
</table>
</center></div>

<p>There are several entries in this control file. For now, make sure that the control 
names and values are entered correctly. You'll learn more about how each one works as you 
go along. Once you get the hang of the control file, you can modify it to suit your own 
mailing-list needs. </p>

<p>Now add a new subroutine, called <tt><font FACE="Courier">SubEdit</font></tt>, to allow 
the editing of the subscriber list. Enter the code in Listing 9.10 into the routine. </p>

<hr>

<blockquote>