ArcObjects Library Reference

# Zoom by Ratio Snippet

Zoom in ActiveView using a ratio of the current extent.

[C#]
```
///<summary>Zoom in ActiveView using a ratio of the current extent.</summary>
///
///<param name="activeView">An IActiveView interface.</param>
///<param name="zoomRatio">A Double that is the ratio to zoom in. Less that 1 zooms in (Example: .75), greater than 1 zooms out (Example: 2).</param>
///
///<remarks>Both the width and height ratio of the zoomed area is preserved.</remarks>
public void ZoomByRatio(ESRI.ArcGIS.Carto.IActiveView activeView, System.Double zoomRatio)
{
if(activeView == null || zoomRatio < 0)
{
return;
}
ESRI.ArcGIS.Geometry.IEnvelope envelope = activeView.Extent;
envelope.Expand(zoomRatio, zoomRatio, true);
activeView.Extent = envelope;
activeView.Refresh();
}
```
[Visual Basic .NET]
```
'''<summary>Zoom in ActiveView using a ratio of the current extent.</summary>
'''
'''<param name="activeView">An IActiveView interface.</param>
'''<param name="zoomRatio">A Double that is the ratio to zoom in. Less that 1 zooms in (Example: .75), greater than 1 zooms out (Example: 2).</param>
'''
'''<remarks>Both the width and height ratio of the zoomed area is preserved.</remarks>
Public Sub ZoomByRatio(ByVal activeView As ESRI.ArcGIS.Carto.IActiveView, ByVal zoomRatio As System.Double)

If activeView Is Nothing OrElse zoomRatio < 0 Then
Return
End If

Dim envelope As ESRI.ArcGIS.Geometry.IEnvelope = activeView.Extent
envelope.Expand(zoomRatio, zoomRatio, True)
activeView.Extent = envelope
activeView.Refresh()

End Sub
```