Public ReadOnly Property Toolbar As Viewer.ViewerToolbar

public Viewer.ViewerToolbar Toolbar {get;}

private ToolStripButton tsbPrint = new System.Windows.Forms.ToolStripButton();

        private void Form1_Load(object sender, EventArgs e)
        {
            System.Windows.Forms.ToolStrip toolStrip;
            System.Windows.Forms.ToolStripItem orgItem;
            System.Windows.Forms.ToolStripButton orgBtn = null;

            // Get the standard Print button, to get the image.
            toolStrip = this.viewer1.Toolbar.ToolStrip;
            orgItem = toolStrip.Items[2];
            if (orgItem is System.Windows.Forms.ToolStripButton)
            {
                orgBtn = (System.Windows.Forms.ToolStripButton)orgItem;
            }

            // Delete the standard Print button.
            toolStrip.Items.RemoveAt(2);

            // Add the Custom button, in place of the standard Print button.
            if (orgBtn == null)
            {
                tsbPrint.Text = "Print";
                tsbPrint.ToolTipText = "Print";
            }
            else
            {
                tsbPrint.Text = orgBtn.Text;
                tsbPrint.ToolTipText = orgBtn.ToolTipText;
                tsbPrint.Image = orgBtn.Image;
            }
            tsbPrint.Enabled = false;

            // Set the event handler of the Custom button.
            tsbPrint.Click += this.PrintButtonClick;

            // Add the custom button to the tool bar.
            toolStrip.Items.Insert(2, tsbPrint);
        }


        //Event to be called when the report is loaded in the Viewer.
        private void viewer1_LoadCompleted(object sender, EventArgs e)
        
        {
            // Enable the Custom button.
            tsbPrint.Enabled = true;
        }

        // Event to be called when the Custom button is clicked.
        private void PrintButtonClick(System.Object sender, System.EventArgs e)
        {
            // Perform the print processing.
            this.viewer1.Print(true, true, false);
        }
    }
}

Private tsbPrint As New System.Windows.Forms.ToolStripButton

Private Sub Form1_Load(...) Handles MyBase.Load
　　Dim toolStrip As System.Windows.Forms.ToolStrip
　　Dim orgBtn As System.Windows.Forms.ToolStripButton = Nothing
　　Dim orgItem As System.Windows.Forms.ToolStripItem

　　' Get the standard Print button, to get the image.
　　toolStrip = Me.Viewer1.Toolbar.ToolStrip
　　orgItem = toolStrip.Items(2)
　　If TypeOf orgItem Is System.Windows.Forms.ToolStripButton Then
　　　　orgBtn = CType(orgItem, ToolStripButton)
　　End If

　　' Delete the standard Print button.。
　　toolStrip.Items.RemoveAt(2)

　　' Add the Custom button, in place of the standard Print button.
　　If orgBtn Is Nothing Then
　　　　tsbPrint.Text = "Print"
　　　　tsbPrint.ToolTipText = "Print"
　　Else
　　　　tsbPrint.Text = orgBtn.Text
　　　　tsbPrint.ToolTipText = orgBtn.ToolTipText
　　　　tsbPrint.Image = orgBtn.Image
　　End If
　　tsbPrint.Enabled = False

　　' Set the event handler of the Custom button.
　　AddHandler tsbPrint.Click, AddressOf Me.PrintButtonClick

　　' Add the custom button to the tool bar.
　　toolStrip.Items.Insert(2, tsbPrint)

End Sub

' Event to be called when the report is loaded in the Viewer.
Private Sub Viewer1_LoadCompleted(...) Handles Viewer1.LoadCompleted
　　'Enable the Custom button.
　　tsbPrint.Enabled = True
End Sub

' Event to be called when the Custom button is clicked.
Private Sub PrintButtonClick(ByVal sender As Object, ByVal e As System.EventArgs)
　　' Perform the print processing.
　　Me.Viewer1.Print(True, True, False)
End Sub