(VB.NET) Fetch 1st N Headers of Search Results

Calls Search to get a message set, then downloads the 1st N messages in the message set. There are two equivalent ways of doing it: (1) iterate from 0 to N-1 and download each message individually, or (2) create a new message set that contains the 1st N messages and pass it to FetchHeaders. Both are demonstrated here.

Download: Chilkat .NET Assemblies

Dim imap As New Chilkat.Imap()

Dim success As Boolean

'  Anything unlocks the component and begins a fully-functional 30-day trial.
success = imap.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf
    Exit Sub
End If


'  Connect to an IMAP server.
success = imap.Connect("mail.chilkatsoft.com")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf
    Exit Sub
End If


'  Login
success = imap.Login("****","****")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf
    Exit Sub
End If


'  Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf
    Exit Sub
End If


Dim messageSet As Chilkat.MessageSet
'  We can choose to fetch UIDs or sequence numbers.
Dim fetchUids As Boolean
fetchUids = true
'  Get the message IDs of all the emails in the mailbox
messageSet = imap.Search("ALL",fetchUids)
If (messageSet Is Nothing ) Then
    TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf
    Exit Sub
End If


Dim numFound As Long
numFound = messageSet.Count
If (numFound = 0) Then
    TextBox1.Text = TextBox1.Text & "No messages found." & vbCrLf

    Exit Sub
End If


'  Get the 1st 10 messages in messageSet.
Dim maxToGet As Long
maxToGet = 10

Dim upperBound As Long
upperBound = 10
If (numFound < upperBound) Then
    upperBound = numFound
End If


Dim i As Long
Dim bUid As Boolean
bUid = messageSet.HasUids
For i = 0 To upperBound - 1

    Dim email As Chilkat.Email
    email = imap.FetchSingleHeader(messageSet.GetId(i),bUid)
    If (email Is Nothing ) Then
        TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf

        Exit Sub

    Else
        '  Do whatever is needed with the email..
        '  ....


    End If

Next


'  Alternatively, create a new message set containing the 1st 10 message id's (UID's)
'  from the search results message set:
Dim firstTen As New Chilkat.MessageSet()

For i = 0 To upperBound - 1
    firstTen.InsertId(messageSet.GetId(i),bUid)
Next



'  Download the 1st ten headers:
Dim bundle As Chilkat.EmailBundle
bundle = imap.FetchHeaders(firstTen)
If (bundle Is Nothing ) Then

    TextBox1.Text = TextBox1.Text & imap.LastErrorText & vbCrLf
    Exit Sub
End If



'  Other examples show how to iterate over the emails contained within the bundle...


'  Disconnect from the IMAP server.
imap.Disconnect()