MainBar Property

Visual Basic
C#

'Declaration
 
Public ReadOnly Property MainBar As System.Windows.Forms.ToolStrip

public System.Windows.Forms.ToolStrip MainBar {get;}

Items on this toolstrip and their index numbers:

0 Toggle sidebar
1 Separator
2 Print
3 Galley mode
4 Separator
5 Copy
6 Find
7 Separator
8 Zoom out
9 Current zoom
10 Zoom in
11 Separator
12 Fit width
13 Fit page
14 Separator
15 Single page view
16 Continuous view
17 Multipage view
18 Refresh
19 Cancel

You can access these items by index with the Insert and RemoveAt methods. Other methods are described in the System.Windows.Forms.ToolStripItemCollection documentation on MSDN.

This code removes the print button and replaces it with one that calls a custom print dialog.

C#

private void Form1_Load(object sender, EventArgs e)
      {
          //Remove the print button. 
          viewer1.Toolbar.MainBar.Items.RemoveAt(2);
          //Remove the extra separator.
          viewer1.Toolbar.MainBar.Items.RemoveAt(1);
          //Add a new button to the end of the main bar with the caption "Print."
          ToolStripButton tsbPrint = new ToolStripButton("Print");
          viewer1.Toolbar.MainBar.Items.Add(tsbPrint);
          //Create a click event handler for the button.
          tsbPrint.Click += new EventHandler(tsbPrint_Click);

          SectionReport1 rpt = new SectionReport1();
          viewer1.LoadDocument(rpt);

      }

      //Call the custom dialog from the new button's click event.
      void tsbPrint_Click(object sender, EventArgs e)
      {
          this.CustomPrint();
      }

//Call the custom print dialog.
      private void CustomPrint()
      {
          frmPrintDlg _printForm = new frmPrintDlg();
          _printForm.ShowDialog(this);
      }

VB.NET

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
    Dim rpt As New SectionReport1
    Viewer1.LoadDocument(rpt)

    'Remove the print button. 
    Viewer1.Toolbar.MainBar.Items.RemoveAt(2)
    'Remove the extra separator.
    Viewer1.Toolbar.MainBar.Items.RemoveAt(1)
    'Add a new button to the end of the main bar with the caption "Print."
    Dim tsbPrint As New ToolStripButton("Print")
    Viewer1.Toolbar.MainBar.Items.Add(tsbPrint)
    'Create a click event handler for the button.
    AddHandler tsbPrint.Click, AddressOf tsbPrint_Click
End Sub

'Call the custom dialog from the new button's click event.
Private Sub tsbPrint_Click(sender As Object, e As EventArgs)
    Me.CustomPrint()
End Sub

'Call the custom print dialog.
Private Sub CustomPrint()
    Dim _printForm As New frmPrintDlg()
    _printForm.ShowDialog(Me)
End Sub

Reference

Viewer.ViewerToolbar Class
Viewer.ViewerToolbar Members