> For the complete documentation index, see [llms.txt](https://docs.wisej.com/api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.wisej.com/api/wisej.web/general/control/wisej.web.focuseventhandler.md).

# FocusEventHandler

Namespace: **Wisej.Web**

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

Represents the method that handles these events: [GotFocus](/api/wisej.web/general/control.md#gotfocus) and [LostFocus](/api/wisej.web/general/control.md#lostfocus).<mark style="color:blue;background-color:green;">Since 3.5.18</mark>

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

```csharp
public delegate void FocusEventHandler(Object sender, FocusEventArgs e)
```

{% endtab %}

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

```visual-basic
Public Delegate Sub FocusEventHandler(ByVal sender As [Object], ByVal e As FocusEventArgs)
```

{% endtab %}
{% endtabs %}

This delegate is not used in Wisej.NET. The [GotFocus](/api/wisej.web/general/control.md#gotfocus) and [LostFocus](/api/wisej.web/general/control.md#lostfocus) events are [EventHandler](https://docs.microsoft.com/dotnet/api/system.eventhandler) to preserve compatibility with existing code.\
Developers handling these events can simply check whether the parameter `e` is of type [FocusEventArgs](/api/wisej.web/general/control/wisej.web.focuseventargs.md) and retrieve the value by casting the event data argument.

## Parameters

| Name       | Type                                                                         | Description                                                                                                  |
| ---------- | ---------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ |
| **sender** | [Object](https://docs.microsoft.com/dotnet/api/system.object)                | The source of the event.                                                                                     |
| **e**      | [FocusEventArgs](/api/wisej.web/general/control/wisej.web.focuseventargs.md) | A [FocusEventArgs](/api/wisej.web/general/control/wisej.web.focuseventargs.md) that contains the event data. |


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