[ObsoleteAttribute("This method is obsolete in .NET 4.5+. Use SearchAsync instead.")]
public IAsyncResult BeginSearch(
	bool returnUids,
	string searchCondition,
	string charset,
	AsyncCallback callback,
	Object state
)

<ObsoleteAttribute("This method is obsolete in .NET 4.5+. Use SearchAsync instead.")>
Public Function BeginSearch ( 
	returnUids As Boolean,
	searchCondition As String,
	charset As String,
	callback As AsyncCallback,
	state As Object
) As IAsyncResult

// To use the code below, import MailBee namespaces at the top of your code.
using MailBee;
using MailBee.ImapMail;

// Put the code below inside your class.

// Declaration of delegate which will update UI.
private delegate void UpdateUIDelegate(Imap imp);

// This method will be called as a delegate by Form.Invoke.
// Since Form.Invoke always executes delegates on UI thread,
// it's safe to update UI in this method (for instance, change
// text in Label or Button controls, disable/enable/add/remove
// controls, or do whatever you need to).
private void UpdateUI(Imap imp)
{
    // It's important to use exception handling here because otherwise
    // we could never know if exception was thrown. This is because this
    // method is called by SearchCallback which is executed on the worker
    // thread. If exception is thrown in UpdateUI method, Form.Invoke then
    // propagates it to SearchCallback by throwing TargetInvocationException
    // in SearchCallback. Now, because SearchCallback is executed on the worker
    // thread, this thread is terminated but no exception is thrown on the UI
    // thread. The worker thread just silently dies. Due to this, the developer
    // should carefully guard all code blocks in callback functions and any
    // methods called by these functions.
    // In this sample, we catch MailBeeException directly in UpdateUI. However,
    // we could also catch TargetInvocationException when calling Invoke in
    // SearchCallback and display .InnerException. The result would be the same
    // (because this sample can throw only MailBeeException in UpdateUI).
    // If UpdateUI method could also throw exceptions of other types, catching
    // TargetInvocationException when calling Invoke would also handle them all.
    // Thus, we need to either catch all exceptions inside the code of the method
    // being called by Form.Invoke or catch TargetInvocationException when calling
    // Form.Invoke itself.
    try
    {
        // Obtain ordinal message numbers of found messages and display them.
        MessageNumberCollection msgNums = (MessageNumberCollection)imp.EndSearch();
        MessageBox.Show(msgNums.ToString());
    }
    catch (MailBeeException e)
    {
        MessageBox.Show(e.Message);
    }

    // Update form's caption area to demonstrate
    // that it's safe to update UI in this method.
    this.Text = "Search finished";
}

// A callback function. Since it's called on Imap worker thread,
// it cannot update controls on the form or otherwise access UI.
// The only UI-related action permitted in worker thread is
// displaying a message box (MessageBox.Show).
// Any updates of UI must take place on message loop thread.
private void SearchCallback(IAsyncResult result)
{
    Imap imp = (Imap)result.AsyncState;

    // To end search and display results on UI thread, we use
    // Form.Invoke passing Imap instance as a parameter.
    Invoke(new UpdateUIDelegate(UpdateUI), new object[] {imp});

    // See comment in UpdateUI.
    try
    {
        imp.Disconnect();
    }
    catch (MailBeeException e)
    {
        MessageBox.Show(e.Message);
    }
}

// The actual code.
private void Form1_Load(object sender, System.EventArgs e)
{
    Imap imp = new Imap();

    // Connect to the server, login and select inbox.
    imp.Connect("imap4.mail.server.com");
    imp.Login("jdoe@server.com", "secret");
    imp.SelectFolder("Inbox");

    // Start async search of messages received since yesterday.
    imp.BeginSearch(false,
        "SINCE \"" + ImapUtils.GetImapDateString(DateTime.Today.AddDays(-1)) + "\"",
        null, new AsyncCallback(SearchCallback), imp);

    // Note: we do not wait until search is finished here.
    // Subsequent code calls will be made in SearchCallback.
}

' To use the code below, import MailBee namespaces at the top of your code.
Imports MailBee
Imports MailBee.ImapMail

' Put the code below inside your class.

' Declaration of delegate which will update UI.
Private Delegate Sub UpdateUIDelegate(ByVal imp As Imap)

' This method will be called as a delegate by Form.Invoke.
' Since Form.Invoke always executes delegates on UI thread,
' it's safe to update UI in this method (for instance, change
' text in Label or Button controls, disable/enable/add/remove
' controls, or do whatever you need to).
Private Sub UpdateUI(ByVal imp As Imap)
    ' It's important to use exception handling here because otherwise
    ' we could never know if exception was thrown. This is because this
    ' method is called by SearchCallback which is executed on the worker
    ' thread. If exception is thrown in UpdateUI method, Form.Invoke then
    ' propagates it to SearchCallback by throwing TargetInvocationException
    ' in SearchCallback. Now, because SearchCallback is executed on the worker
    ' thread, this thread is terminated but no exception is thrown on the UI
    ' thread. The worker thread just silently dies. Due to this, the developer
    ' should carefully guard all code blocks in callback functions and any
    ' methods called by these functions.
    ' In this sample, we catch MailBeeException directly in UpdateUI. However,
    ' we could also catch TargetInvocationException when calling Invoke in
    ' SearchCallback and display .InnerException. The result would be the same
    ' (because this sample can throw only MailBeeException in UpdateUI).
    ' If UpdateUI method could also throw exceptions of other types, catching
    ' TargetInvocationException when calling Invoke would also handle them all.
    ' Thus, we need to either catch all exceptions inside the code of the method
    ' being called by Form.Invoke or catch TargetInvocationException when calling
    ' Form.Invoke itself.
    Try
        ' Obtain ordinal message numbers of found messages and display them.
        Dim msgNums As MessageNumberCollection = CType(imp.EndSearch(), MessageNumberCollection)
        MessageBox.Show(msgNums.ToString())
    Catch e As MailBeeException
        MessageBox.Show(e.Message)
    End Try

    ' Update form's caption area to demonstrate
    ' that it's safe to update UI in this method.
    Me.Text = "Search finished"
End Sub

' A callback function. Since it's called on Imap worker thread,
' it cannot update controls on the form or otherwise access UI.
' The only UI-related action permitted in worker thread is
' displaying a message box (MessageBox.Show).
' Any updates of UI must take place on message loop thread.
Private Sub SearchCallback(ByVal result As IAsyncResult)
    Dim imp As Imap = CType(result.AsyncState, Imap)

    ' To end search and display results on UI thread, we use
    ' Form.Invoke passing Imap instance as a parameter.
    Invoke(New UpdateUIDelegate(AddressOf UpdateUI), New Object() {imp})

    ' See comment in UpdateUI.
    Try
        imp.Disconnect()
    Catch e As MailBeeException
        MessageBox.Show(e.Message)
    End Try
End Sub

' The actual code.
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim imp As New Imap

    ' Connect to the server, login and select inbox.
    imp.Connect("imap4.mail.server.com")
    imp.Login("jdoe@server.com", "secret")
    imp.SelectFolder("Inbox")

    ' Start async search of messages received since yesterday.
    imp.BeginSearch(False, "SINCE """ & _
        ImapUtils.GetImapDateString(DateTime.Today.AddDays(-1)) & _
        """", Nothing, New AsyncCallback(AddressOf SearchCallback), imp)

    ' Note: we do not wait until search is finished here.
    ' Subsequent code calls will be made in SearchCallback.
End Sub