# Accordion

Namespace: **Wisej.Web**

Assembly: **Wisej.Framework** (4.0.0.0)

* [Control](/api/wisej.web/general/control.md)
  * [Accordion](/api/wisej.web/containers/accordion.md)

Displays collapsible set of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) panels for presenting information in a limited amount of space.

{% tabs %}
{% tab title="C#" %}

```csharp
public class Accordion : Control, ISupportInitialize
```

{% endtab %}

{% tab title="VB.NET" %}

```visual-basic
Public Class Accordion
    Inherits Control
    Implements ISupportInitialize
```

{% endtab %}
{% endtabs %}

## Constructors

### ![](/files/hsR4ok3152WyAf8J2C1u) Accordion()

Initializes a new instance of the [Accordion](/api/wisej.web/containers/accordion.md) class.

### ![](/files/hsR4ok3152WyAf8J2C1u) Accordion(panels, onSelectedIndexChanged)

Initializes a new instance of the [Accordion](/api/wisej.web/containers/accordion.md) class with the specified settings.

| Name                       | Type                                                                                  | Description                                                                                                                     |
| -------------------------- | ------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| **panels**                 | [AccordionPanel\[\]](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) | An array of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) objects to be added to the panel. |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2)   | An Action delegate to handle the [SelectedIndexChanged](#selectedindexchanged) event.                                           |

### ![](/files/hsR4ok3152WyAf8J2C1u) Accordion(location, size, onSelectedIndexChanged)

Initializes a new instance of the [Accordion](/api/wisej.web/containers/accordion.md) class with the specified settings.

| Name                       | Type                                                                                | Description                                                                           |
| -------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
| **location**               | [Point](https://docs.microsoft.com/dotnet/api/system.drawing.point)                 | The location of the panel on its parent control.                                      |
| **size**                   | [Size](https://docs.microsoft.com/dotnet/api/system.drawing.size)                   | The size of the panel.                                                                |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2) | An Action delegate to handle the [SelectedIndexChanged](#selectedindexchanged) event. |

### ![](/files/hsR4ok3152WyAf8J2C1u) Accordion(location, size, panels, onSelectedIndexChanged)

Initializes a new instance of the [Accordion](/api/wisej.web/containers/accordion.md) class with the specified settings.

| Name                       | Type                                                                                  | Description                                                                                                                     |
| -------------------------- | ------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| **location**               | [Point](https://docs.microsoft.com/dotnet/api/system.drawing.point)                   | The location of the panel on its parent control.                                                                                |
| **size**                   | [Size](https://docs.microsoft.com/dotnet/api/system.drawing.size)                     | The size of the panel.                                                                                                          |
| **panels**                 | [AccordionPanel\[\]](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) | An array of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) objects to be added to the panel. |
| **onSelectedIndexChanged** | [Action\<Object, EventArgs>](https://docs.microsoft.com/dotnet/api/system.action-2)   | An Action delegate to handle the [SelectedIndexChanged](#selectedindexchanged) event.                                           |

## Properties

### ![](/files/hsR4ok3152WyAf8J2C1u) BorderStyle

[BorderStyle](/api/wisej.web/enumerations/wisej.web.borderstyle.md): Returns or sets the type of border that is drawn around the [Accordion](/api/wisej.web/containers/accordion.md) panel. (Default: `Solid`)

### ![](/files/hsR4ok3152WyAf8J2C1u) ClientArea

[Rectangle](https://docs.microsoft.com/dotnet/api/system.drawing.rectangle): Returns the client rectangle to use in the designer.

### ![](/files/hsR4ok3152WyAf8J2C1u) Collapsible

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets a value indicating whether the Accordion control collapses when all the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) children are collapsed. (Default: `False`)

When this property is set to false (default) one panel is always expanded.

### ![](/files/hsR4ok3152WyAf8J2C1u) DisplayRectangle

[Rectangle](https://docs.microsoft.com/dotnet/api/system.drawing.rectangle): Returns the rectangle that represents the virtual display area of the control.

### ![](/files/hsR4ok3152WyAf8J2C1u) HeaderSize

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the size of the header. When the header is horizontal, the size if the height; when it's vertical, the size if the width. Set it to -1 to reset to the size set in the current theme.

### ![](/files/hsR4ok3152WyAf8J2C1u) ImageList

[ImageList](/api/wisej.web/content/imagelist.md): Returns or sets the images to display on the panel's title bar. (Default: `null`)

### ![](/files/hsR4ok3152WyAf8J2C1u) PanelCount

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns the number of panels in the container. (Default: `0`)

### ![](/files/hsR4ok3152WyAf8J2C1u) Panels

[PanelCollection](/api/wisej.web/containers/accordion/wisej.web.accordion.panelcollection.md): Returns the collection of panels in the container.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedIndex

[Int32](https://docs.microsoft.com/dotnet/api/system.int32): Returns or sets the index of the currently selected panel. (Default: `-1`)

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception)\
  The value is less than -1.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedOnTop

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets a value indicating whether the selected panel is moved to the top of the [Accordion](/api/wisej.web/containers/accordion.md) container. (Default: `False`)

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedPanel

[AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md): Returns or sets the currently selected panel. (Default: `null`)

### ![](/files/hsR4ok3152WyAf8J2C1u) ShowToolTips

[Boolean](https://docs.microsoft.com/dotnet/api/system.boolean): Returns or sets whether a panel's ToolTip is shown when the mouse passes over the panel's title. (Default: `True`)

## Methods

### ![](/files/lzopMboA31bVq8UIcbT3) CreateControlsInstance()

This member overrides [CreateControlsInstance](/api/wisej.web/general/control.md#createcontrolsinstance).

**Returns:** [ControlCollection](/api/wisej.web/general/control/wisej.web.control.controlcollection.md). A new instance of [ControlCollection](/api/wisej.web/general/control/wisej.web.control.controlcollection.md) assigned to the control.

### ![](/files/hsR4ok3152WyAf8J2C1u) DeselectPanel(index)

Makes the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) following the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) with the specified index the current panel.

| Parameter | Type                                                        | Description                                                                                                                                         |
| --------- | ----------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------- |
| **index** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32) | The index in the [Panels](#panels) collection of the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) to deselect. |

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception)*index* is less than 0 or greater than the number of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) controls in the [Panels](#panels) collection minus 1.

### ![](/files/hsR4ok3152WyAf8J2C1u) DeselectPanel(panel)

Makes the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) following the specified [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) the current panel.

| Parameter | Type                                                                              | Description                                                                                        |
| --------- | --------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- |
| **panel** | [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) | The [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) to deselect. |

**Throws:**

* [ArgumentNullException](https://docs.microsoft.com/dotnet/api/system.argumentnullexception)*panel* is null.

### ![](/files/hsR4ok3152WyAf8J2C1u) DeselectPanel(panelName)

Makes the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) following the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) the specified name the current panel.

| Parameter     | Type                                                          | Description                                                                  |
| ------------- | ------------------------------------------------------------- | ---------------------------------------------------------------------------- |
| **panelName** | [String](https://docs.microsoft.com/dotnet/api/system.string) | The [Name](/api/wisej.web/general/control.md#name) of the panel to deselect. |

**Throws:**

* [ArgumentNullException](https://docs.microsoft.com/dotnet/api/system.argumentnullexception)*panelName* is null; or *panelName* does not match the [Name](/api/wisej.web/general/control.md#name) property of any [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) in the [Panels](#panels) collection.

### ![](/files/hsR4ok3152WyAf8J2C1u) GetControl(index)

Returns the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) panel at the specified location.

| Parameter | Type                                                        | Description                                                                                                |
| --------- | ----------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- |
| **index** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32) | The index of the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) to get. |

**Returns:** [Control](/api/wisej.web/general/control.md). The [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) at the specified location.

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception)*index* is less than 0 or greater than the number of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) controls in the [Panels](#panels) collection minus 1.

### ![](/files/lzopMboA31bVq8UIcbT3) GetItems()

Returns an array of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) controls that belong to the [Accordion](/api/wisej.web/containers/accordion.md) control.

**Returns:** [Object\[\]](https://docs.microsoft.com/dotnet/api/system.object). An array of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) controls that belong to the [Accordion](/api/wisej.web/containers/accordion.md).

### ![](/files/lzopMboA31bVq8UIcbT3) GetToolTipText(item)

Returns the ToolTip for the specified [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md).

| Parameter | Type                                                          | Description                                                                                                          |
| --------- | ------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- |
| **item**  | [Object](https://docs.microsoft.com/dotnet/api/system.object) | The [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) that owns the desired ToolTip. |

**Returns:** [String](https://docs.microsoft.com/dotnet/api/system.string). The ToolTip text.

### ![](/files/lzopMboA31bVq8UIcbT3) OnControlAdded(e)

Fires the [ControlAdded](/api/wisej.web/general/control.md#controladded) event.

| Parameter | Type                                                                             | Description |
| --------- | -------------------------------------------------------------------------------- | ----------- |
| **e**     | [ControlEventArgs](/api/wisej.web/general/control/wisej.web.controleventargs.md) |             |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDeselected(e)

Fires the [Deselected](#deselected) event.

| Parameter | Type                                                                                      | Description                                                                                                                  |
| --------- | ----------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
| **e**     | [AccordionEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioneventargs.md) | A [TabControlEventArgs](/api/wisej.web/containers/tabcontrol/wisej.web.tabcontroleventargs.md) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnDeselecting(e)

Fires the [Deselecting](#deselecting) event.

| Parameter | Type                                                                                                  | Description                                                                                                                           |
| --------- | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| **e**     | [AccordionCancelEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioncanceleventargs.md) | A [AccordionCancelEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioncanceleventargs.md) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnEnter(e)

Fires the [Enter](/api/wisej.web/general/control.md#enter) event of the currently active [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md).

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnLayout(e)

Fires the [Layout](/api/wisej.web/general/control.md#layout) event.

| Parameter | Type                                                                           | Description                                                                                                    |
| --------- | ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------- |
| **e**     | [LayoutEventArgs](/api/wisej.web/general/control/wisej.web.layouteventargs.md) | A [LayoutEventArgs](/api/wisej.web/general/control/wisej.web.layouteventargs.md) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnLeave(e)

Fires the [Leave](/api/wisej.web/general/control.md#leave) event of the currently active [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md).

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSelected(e)

Fires the [Selected](#selected) event.

| Parameter | Type                                                                                      | Description                                                                                                               |
| --------- | ----------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- |
| **e**     | [AccordionEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioneventargs.md) | A [AccordionEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioneventargs.md) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSelectedIndexChanged(e)

Fires the [SelectedIndexChanged](#selectedindexchanged) event.

| Parameter | Type                                                                | Description                                                                                         |
| --------- | ------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| **e**     | [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) | A [EventArgs](https://docs.microsoft.com/dotnet/api/system.eventargs) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnSelecting(e)

Fires the [Selecting](#selecting) event.

| Parameter | Type                                                                                                  | Description                                                                                                                           |
| --------- | ----------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| **e**     | [AccordionCancelEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioncanceleventargs.md) | A [AccordionCancelEventArgs](/api/wisej.web/containers/accordion/wisej.web.accordioncanceleventargs.md) that contains the event data. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnWebEvent(e)

Processes the event from the client.

| Parameter | Type                                                        | Description      |
| --------- | ----------------------------------------------------------- | ---------------- |
| **e**     | [WisejEventArgs](/api/wisej.core/general/wisejeventargs.md) | Event arguments. |

### ![](/files/lzopMboA31bVq8UIcbT3) OnWebRender(config)

Renders the client component.

| Parameter  | Type                                                          | Description                   |
| ---------- | ------------------------------------------------------------- | ----------------------------- |
| **config** | [Object](https://docs.microsoft.com/dotnet/api/system.object) | Dynamic configuration object. |

### ![](/files/lzopMboA31bVq8UIcbT3) RemoveAll()

Removes all the panels and additional controls from this tab control.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectPanel(index)

Makes the [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) with the specified index the current [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md).

| Parameter | Type                                                        | Description                                                         |
| --------- | ----------------------------------------------------------- | ------------------------------------------------------------------- |
| **index** | [Int32](https://docs.microsoft.com/dotnet/api/system.int32) | The index in the [Panels](#panels) collection of the tab to select. |

**Throws:**

* [ArgumentOutOfRangeException](https://docs.microsoft.com/dotnet/api/system.argumentoutofrangeexception)*index* is less than 0 or greater than the number of [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) controls in the [Panels](#panels) collection minus 1.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectPanel(panel)

Makes the specified [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) the current [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md).

| Parameter | Type                                                                              | Description                                                                                      |
| --------- | --------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
| **panel** | [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) | The [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) to select. |

**Throws:**

* [ArgumentNullException](https://docs.microsoft.com/dotnet/api/system.argumentnullexception)*panel* is null.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectPanel(panelName)

Makes [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) with the specified name the current [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md).

| Parameter     | Type                                                          | Description                                                              |
| ------------- | ------------------------------------------------------------- | ------------------------------------------------------------------------ |
| **panelName** | [String](https://docs.microsoft.com/dotnet/api/system.string) | The [Name](/api/wisej.web/general/control.md#name) of the tab to select. |

**Throws:**

* [ArgumentNullException](https://docs.microsoft.com/dotnet/api/system.argumentnullexception)*panelName* is null; or *panelName* does not match the [Name](/api/wisej.web/general/control.md#name) property of any [AccordionPanel](/api/wisej.web/containers/accordion/wisej.web.accordionpanel.md) in the [Panels](#panels) collection.

## Events

### ![](/files/hsR4ok3152WyAf8J2C1u) Deselected

[AccordionEventHandler](/api/wisej.web/containers/accordion/wisej.web.accordioneventhandler.md) Fired when a panel is deselected.

### ![](/files/hsR4ok3152WyAf8J2C1u) Deselecting

[AccordionCancelEventHandler](/api/wisej.web/containers/accordion/wisej.web.accordioncanceleventhandler.md) Occurs before a panel is deselected, enabling a handler to cancel the panel change.

### ![](/files/hsR4ok3152WyAf8J2C1u) Selected

[AccordionEventHandler](/api/wisej.web/containers/accordion/wisej.web.accordioneventhandler.md) Fired when a panel is selected.

### ![](/files/hsR4ok3152WyAf8J2C1u) SelectedIndexChanged

[EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) Fired when the [SelectedIndex](#selectedindex) property has changed.

### ![](/files/hsR4ok3152WyAf8J2C1u) Selecting

[AccordionCancelEventHandler](/api/wisej.web/containers/accordion/wisej.web.accordioncanceleventhandler.md) Occurs before a panel is selected, enabling a handler to cancel the panel change.

## Implements

| Name                                                                              | Description                                                                                                           |
| --------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| [IUserData](/api/wisej.web/interfaces/wisej.web.iuserdata.md)                     | Provides access to the `UserData` and `Tag` properties associated to the component implementing this interface.       |
| [IBindableComponent](/api/wisej.web/data-binding/wisej.web.ibindablecomponent.md) | Bindable components implement this interface.                                                                         |
| [IDropTarget](/api/wisej.web/interfaces/wisej.web.idroptarget.md)                 | Controls that support drag & drop operations implement this interface.                                                |
| [IWisejComponent](/api/wisej.core/interfaces/wisej.core.iwisejcomponent.md)       | All wisej components implement this interface.                                                                        |
| [IWisejControl](/api/wisej.core/interfaces/wisej.core.iwisejcontrol.md)           | All wisej controls derived from the [Control](/api/wisej.web/general/control.md) class must implement this interface. |
| [IWisejSerializable](/api/wisej.core/interfaces/wisej.core.iwisejserializable.md) | Allows an object to serialize itself.                                                                                 |


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