# Expandability

## Content



By default, the [C1Expander](/componentone/api/wpf/online-extended/dotnet-framework-api/C1.WPF.Extended.4.6.2/C1.WPF.Extended.C1Expander.html) control's [C1Expander.IsExpandable](/componentone/api/wpf/online-extended/dotnet-framework-api/C1.WPF.Extended.4.6.2/C1.WPF.Extended.C1Expander.IsExpandable.html) property is set to **True**, meaning that the content can be expanded by clicking on the header bar. In some instances, such as when you'd like to prevent expansion until a specific event, you may not want to allow for expansion of the control; in this case, you would set the **IsExpandable** property to **False**.

Once the **IsExpandable** property is set to **False**, users can no longer interact with the control. If the user hovers over the control when the ****IsExpandable**** property is set to **False**, no mouse-over effect will appear; if the user clicks on the header when the **IsExpandable** property is set to **False**, the control will remain collapsed.

The table below illustrates the behavioral effect of each **IsExpandable** property setting.

|   **IsExpandable**   |   **Result**   |
| --- | --- |
|   True   |   **![](https://cdn.mescius.io/document-site-files/images/babf1807-69aa-4d8a-96b6-d6c6d9325368/expandability_files/image001.png)**   |
|   False   |   **![](https://cdn.mescius.io/document-site-files/images/babf1807-69aa-4d8a-96b6-d6c6d9325368/expandability_files/image002.png)**   |