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一些简单的编程例子 都是网页的形式

<p>发送电子邮件附件</p>
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<p>与简单电子邮件发送程序相比，本示例程序多了框架控件及其中的内容。框架中的列表框用来显示附件的路径，另外两个按钮的作用相信你一看就知道。真正发送附件的代码在Send message按钮的Click事件中。在该事件中多了一小段代码：</p>
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<p>For i = 0 To lstAttachments.ListCount - 1</p>
<p>    lstAttachments.ListIndex = i</p>
<p>    m_strEncodedFiles = m_strEncodedFiles & _</p>
<p>    UUEncodeFile(lstAttachments.Text) & vbCrLf</p>
<p>Next i </p>
<p>上面的代码将附件的路径作为参数传递给UUEncodeFile函数。该函数的作用是按照我们前面所讲的算法对字符进行编码。编码后的数据被保存在一个模块级变量m_strEncodedFile中。然后该变量的内容被添加到邮件正文中：</p>
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<p>'Add atacchments </p>
<p>strMessage = txtMessage & vbCrLf & vbCrLf & m_strEncodedFiles</p>
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<p>剩下的事情就再清楚不过了。编码后的数据作为邮件的一部分发送出却，你不需编写特别的代码处理SMTP服务器。下面的函数UUEncodeFile的代码：</p>
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<p>Public Function UUEncodeFile(strFilePath As String) As String</p>
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<p>Dim intFile As Integer     'file handler</p>
<p>Dim intTempFile As Integer 'temp file</p>
<p>Dim lFileSize As Long      'size of the file</p>
<p>Dim strFileName As String  'name of the file</p>
<p>Dim strFileData As String  'file data chunk</p>
<p>Dim lEncodedLines As Long  'number of encoded lines</p>
<p>Dim strTempLine As String  'temporary string</p>
<p>Dim i As Long              'loop counter</p>
<p>Dim j As Integer           'loop counter</p>
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<p>Dim strResult As String</p>
<p>'</p>
<p>'Get file name</p>
<p>strFileName = Mid$(strFilePath, InStrRev(strFilePath, "\") + 1)</p>
<p>'</p>
<p>'Insert first marker: "begin 664 ..."</p>
<p>strResult = "begin 664 " + strFileName + vbLf</p>
<p>'</p>
<p>'Get file size</p>
<p>lFileSize = FileLen(strFilePath)</p>
<p>lEncodedLines = lFileSize \ 45 + 1</p>
<p>'</p>
<p>'Prepare buffer to retrieve data from</p>
<p>'the file by 45 symbols chunks</p>
<p>strFileData = Space(45)</p>
<p>'</p>
<p>intFile = FreeFile</p>
<p>'</p>
<p>Open strFilePath For Binary As intFile</p>
<p>For i = 1 To lEncodedLines</p>
<p>    'Read file data by 45-bytes cnunks</p>
<p>    '</p>
<p>    If i = lEncodedLines Then</p>
<p>        'Last line of encoded data often is not</p>
<p>        'equal to 45, therefore we need to change</p>
<p>        'size of the buffer</p>
<p>        strFileData = Space(lFileSize Mod 45)</p>
<p>    End If</p>
<p>    'Retrieve data chunk from file to the buffer</p>
<p>Get intFile, , strFileData</p>
<p>    'Add first symbol to encoded string that informs</p>
<p>    'about quantity of symbols in encoded string.</p>
<p>    'More often "M" symbol is used.</p>
<p>strTempLine = Chr(Len(strFileData) + 32)</p>
<p>    '</p>
<p>    If i = lEncodedLines And (Len(strFileData) Mod 3) Then</p>
<p>        'If the last line is processed and length of</p>
<p>        'source data is not a number divisible by 3, </p>
<p>        'add one or two blankspace symbols</p>
<p>        strFileData = strFileData + Space(3 -             (Len(strFileData) Mod 3))</p>
<p>    End If</p>
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<p>    For j = 1 To Len(strFileData) Step 3</p>
<p>        'Breake each 3 (8-bits) bytes to 4 (6-bits) bytes</p>
<p>        '</p>
<p>        '1 byte</p>
<p>        strTempLine = strTempLine +             Chr(Asc(Mid(strFileData, j, 1)) \ 4 + 32)</p>
<p>        '2 byte</p>
<p>        strTempLine = strTempLine + _</p>
<p>            Chr((Asc(Mid(strFileData, j, 1)) Mod 4) * 16             + Asc(Mid(strFileData, j + 1, 1)) \ 16 + 32)</p>
<p>        '3 byte</p>
<p>        strTempLine = strTempLine + _</p>
<p>            Chr((Asc(Mid(strFileData, j + 1, 1)) Mod 16) * 4             + Asc(Mid(strFileData, j + 2, 1)) \ 64 + 32)</p>
<p>        '4 byte</p>
<p>        strTempLine = strTempLine + _</p>
<p>            Chr(Asc(Mid(strFileData, j + 2, 1)) Mod 64 + 32)</p>
<p>    Next j</p>
<p>    'add encoded line to result buffer</p>
<p>    strResult = strResult + strTempLine + vbLf</p>
<p>    'reset line buffer</p>
<p>    strTempLine = ""</p>
<p>Next i</p>
<p>Close intFile</p>
<p>'add the end marker</p>
<p>strResult = strResult & "'" & vbLf + "end" + vbLf</p>
<p>'asign return value</p>
<p>UUEncodeFile = strResult</p>
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<p>End Function</p>
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<p>我不敢说上面的代码的运行速度是最快的，但却是我试验多次达到的最快速度。VB处理字符并不是它的特长，所以如果速度对你来讲至关重要的话，请尝试用C++或Delphi开发的库或组件。</p>
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