To set the initial zoom mode, set the ZoomMode property to ActualSize, PageWidth, TextWidth, WholePage (default), or Custom. This property can be set at either in the designer or in code.

In the Smart Designer

1. Click the Layout button in the PreviewPane floating toolbar to open Layout dialog box.
2. Select PageWidth from the drop-down menu next to the Zoom Mode:
   

In the Properties window

1. Locate the PreviewPane property for C1PrintPreviewControl in the Properties window and expand the properties node.
2. Set the ZoomMode property to PageWidth.
       

In Code

Add the following code to the Form_Load event to set the ZoomMode to PageWidth:

To write code in Visual Basic

Me.C1PrintPreviewControl1.PreviewPane.ZoomMode = C1.Win.C1Preview.ZoomModeEnum.PageWidth

To write code in C#

this.c1PrintPreviewControl1.PreviewPane.ZoomMode = C1.Win.C1Preview.ZoomModeEnum.PageWidth;

What You've Accomplished

When the document loads, the page zooms into the page width: