# Zoom Factor Changed

C1Zoom.ZoomFactorChanged event occurs when C1Zoom.ZoomFactor changed. For example, you can show current ZoomFactor on the Titlebar of the Form.

## Content

C1Zoom.ZoomFactorChanged event occurs when C1Zoom.ZoomFactor changed. For example, you can show current ZoomFactor on the Titlebar of the Form.

[C#]

```csharp
private void c1Zoom1_ZoomFactorChanged(object sender, EventArgs e)
{
  this.Text = string.Format("{0:P}", c1Zoom1.ZoomFactor);
}
```

[Visual Basic]

```vbnet
Private Sub C1Zoom1_ZoomFactorChanged(sender As System.Object, e As System.EventArgs) Handles C1Zoom1.ZoomFactorChanged
  Me.Text = String.Format("{0:P}", C1Zoom1.ZoomFactor)
End Sub
```

To see how the **ZoomFactorChanged** event works you can look at the **ZoomFactorFeatures** demo in the **TouchToolKit for WinForms** explorer sample.

When you select the **ZoomFactorFeatures** demo, the default ZoomFactor appears as 100%:

![](https://cdn.mescius.io/document-site-files/images/b72f799f-5669-44a4-8119-5f3343d59999/images/beforezoomfactorchange.png)

Now, select the area on the form that you wish to zoom by pinching two fingers together and then gradually expanding your fingers apart. The following image shows the form in the preview mode before the items zoom in:

![zoom the area](https://cdn.mescius.io/document-site-files/images/b72f799f-5669-44a4-8119-5f3343d59999/images/zooming.png)

Release your fingers and the form appears like the following:

![how it looks after the zoom](https://cdn.mescius.io/document-site-files/images/b72f799f-5669-44a4-8119-5f3343d59999/images/afterzoom.png)

The log on the sample shows the changed value of the **ZoomFactor** property:

![zoom factor event for changing the zoom](https://cdn.mescius.io/document-site-files/images/b72f799f-5669-44a4-8119-5f3343d59999/images/zoomfactorchangedevent.png)