# CheckBox
### Introduction
CheckBox is a component which can be used to represent a bool value (true or false) at runtime.
### Layout Requirements
The CheckBox control has no requirements – an empty container is sufficient. [](https://github.com/flatredball/FlatRedBallDocs/blob/main/media/2017-12-img_5a485e78076db.png)
### TextInstance
The CheckBox control can optionally include a Text instance named **TextInstance**. Setting the CheckBox control’s **Text** property changes the **TextInstance’s** displayed string.
### IsChecked
A nullable bool indicating whether the CheckBox is checked. Note that the value is a bool? , but the current implementation of FlatRedBall.Forms does not support the \*indeterminate \*value (a value of null ). IsChecked can be read from the control or can be explicitly set on the control as shown in the following example:
```lang:c#
checkbox.IsChecked = true;
```
### CheckBox Events
CheckBox provides events for when it is checked and unchecked as shown in the following example:
```lang:c#
void CustomInitialize()
{
var checkbox = TutorialScreenGum
.GetGraphicalUiElementByName("CheckBoxInstance")
.FormsControlAsObject as CheckBox;
checkbox.Checked += HandleCheckboxChecked;
checkbox.Unchecked += HandleCheckboxUnchecked;
}
private void HandleCheckboxChecked(object sender, EventArgs e)
{
// Perform checked-related logic
}
private void HandleCheckboxUnchecked(object sender, EventArgs e)
{
// Perform unchecked-related logic
}
```
CheckBox also exposes the more general Click event which can be used to handle any click regardless of IsChecked state, as shown in the following example:
```lang:c#
void CustomInitialize()
{
var checkbox = TutorialScreenGum
.GetGraphicalUiElementByName("CheckBoxInstance")
.FormsControlAsObject as CheckBox;
checkbox.Click += HanleCheckboxClick;
}
private void HanleCheckboxClick(object sender, EventArgs e)
{
// Perform click-related logic
}
```
---
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