HelpBox

A HelpBox displays a message to the user. You can set the type of message to display, such as a warning or an error. You can also set the message to display as rich text, or add a button or a link to the HelpBox.

Create a HelpBox

You can create a HelpBox with UXML and C#. The following C# example creates a HelpBox with the message “Help text” and the information icon:

HelpBox helpBox = new HelpBox("Help text", HelpBoxMessageType.Info);

Example

The following UXML example creates a HelpBox with a warning message:

<UXML xmlns="UnityEngine.UIElements" xmlns:uie="UnityEditor.UIElements">
    <HelpBox text="UXML Help Box" message-type="Info" name="the-uxml-help-box" />
</UXML>

The following C# example illustrates some of the customizable functionalities of the HelpBox:

/// <sample>
// Get a reference to the help box from UXML and update its text.
var uxmlHelpBox = container.Q<HelpBox>("the-uxml-help-box");
uxmlHelpBox.text += " (Updated in C#)";

// Create a new help box and give it a style class.
var csharpHelpBox = new HelpBox("This is a styled warning type help box.", HelpBoxMessageType.Warning);
csharpHelpBox.AddToClassList("some-styled-help-box");
container.Add(csharpHelpBox);

// Create an Error Type help box.
var errorHelpBox = new HelpBox("This is an error type help box.", HelpBoxMessageType.Error);
container.Add(errorHelpBox);

// Create a help box with no icon.
var standardHelpBox = new HelpBox("This is a help box without an icon.", HelpBoxMessageType.None);
container.Add(standardHelpBox);

// Create an Info Type help box with some long text.
var infoHelpBox = new HelpBox("This is a help box with a short paragraph. The content here should help wrap the help box when the window size is small enough. Feel free to resize the sample window to see this wrap and unwrap.", HelpBoxMessageType.Info);
container.Add(infoHelpBox);

// Create a typed help box with a call-to-action button.
var helpBoxWithCTAButton = new HelpBox("This is a help box with a call to action button.", HelpBoxMessageType.Warning);
helpBoxWithCTAButton.buttonText = "Action";
helpBoxWithCTAButton.onButtonClicked += () => Debug.Log("Action Button Clicked");
container.Add(helpBoxWithCTAButton);

// Create a typed help box with a call-to-action button and link.
var helpBoxWithCTAButtonAndLink = new HelpBox("This is a help box with a call to action button and a link.", HelpBoxMessageType.Warning);
helpBoxWithCTAButtonAndLink.buttonText = "Action";
helpBoxWithCTAButtonAndLink.onButtonClicked += () => Debug.Log("Action Button Clicked");
helpBoxWithCTAButtonAndLink.linkHref = "https://www.unity.com";
helpBoxWithCTAButtonAndLink.linkText = "Visit Unity!";
container.Add(helpBoxWithCTAButtonAndLink);
/// </sample>

To try this example live in Unity, go to Window > UI Toolkit > Samples.

C# base class and namespace

C# class: HelpBox
Namespace: UnityEngine.UIElements
Base class: VisualElement

Member UXML attributes

This element has the following member attributes:

Name	Type	Description
`button-text`	`string`	The action button’s text value. Provide a value to create a new `Button` or update the text of an existing one.
`link-href`	`string`	The hyperlink’s reference value. Provide a value to create a `Label` element with a hyperlink rich text tag as its value if none exists. The value is used as the hyperlink reference value. If no `HelpBox.linkText` is provided, this value is used as the hyperlink’s text. This property does not return the hyperlink rich text tag.
`link-text`	`string`	The hyperlink’s text value. Provide a value to create a `Label` if none exists. This property represents the readable string of the hyperlink. If a `HelpBox.linkHref` is provided, it renders as a hyperlink using rich text tags; otherwise, it displays as plain text. This property does not return the hyperlink rich text tag.
`message-type`	`UIElements.HelpBoxMessageType`	The type of message.
`text`	`string`	The message text.

Inherited UXML attributes

This element inherits the following attributes from its base class:

Name	Type	Description
`focusable`	`boolean`	Whether an element can potentially receive focus. If false, the element can’t receive focus. If true, the element receives focus only when its `Focusable.canGrabFocus` property is also true.
`tabindex`	`int`	An integer used to sort focusable elements in the focus ring. Must be greater than or equal to zero. Setting the `tabIndex` value to less than `0` (for example, `−1`) removes the element from the focus ring and tab navigation.

This element also inherits the following attributes from VisualElement:

Name	Type	Description
`content-container`	`string`	Logical container where child elements are added. If a child is added to this element, the child is added to this element’s content container instead. When iterating over the `VisualElement.Children` of an element, the element’s content container hierarchy is used instead of the element itself. This can lead to unexpected results, such as elements being ignored by the navigation events if they are not directly in the content container’s hierarchy. Refer to `IFocusRing` for more information. If the content container is the same as the element itself, child elements are added directly to the element. This is true for most elements but can be overridden by more complex types. The `ScrollView`, for example, has a content container that is different from itself. In that case, child elements added to the scroll view are added to its content container element instead. While the physical parent (`VisualElement.Hierarchy.parent`) of the child elements is the scroll view’s content container element, their logical parent (`VisualElement.parent`) still refers to the scroll view itself. Since some of the scroll view’s focusable children are not part of its logical hierarchy, like its `Scroller` elements, these focusable children are not considered by default when using sequential navigation. Refer to How can I change what element is focused next for an example of a workaround solution if the default navigation rules don’t correspond to your needs.
`data-source`	`Object`	Assigns a data source to this VisualElement which overrides any inherited data source. This data source is inherited by all children.
`data-source-path`	`string`	Path from the data source to the value.
`data-source-type`	`System.Type`	The possible type of data source assignable to this VisualElement. This information is only used by the UI Builder as a hint to provide some completion to the data source path field when the effective data source cannot be specified at design time.
`enabled`	`boolean`	Returns true if the `VisualElement` is enabled locally. This flag isn’t changed if the VisualElement is disabled implicitly by one of its parents. To verify this, use `enabledInHierarchy`.
`language-direction`	`UIElements.LanguageDirection`	Indicates the directionality of the element’s text. The value will propagate to the element’s children. Setting `languageDirection` to `RTL` can only get the basic RTL support like text reversal. To get more comprehensive RTL support, such as line breaking, word wrapping, or text shaping, you must enable Advance Text Generator.
`name`	`string`	The name of this VisualElement. Use this property to write USS selectors that target a specific element. The standard practice is to give an element a unique name.
`picking-mode`	`UIElements.PickingMode`	Determines if this element can be the target of pointer events or picked by `IPanel.Pick` queries. Elements can not be picked if: - They are invisible- Their `style.display` is set to `DisplayStyle.None` Elements with a picking mode of `PickingMode.Ignore` never receive the hover pseudo-state.
`style`	`string`	Sets the style values on a `VisualElement`. The returned style data, computed from USS files or inline styles written to this object in C#, doesn’t represent the fully resolved styles, such as the final height and width of a VisualElement. To access these fully resolved styles, use `resolvedStyle`. For information about how to use this property and all the supported USS properties, refer to the Apply styles in C# scripts and USS properties reference manual pages.
`tooltip`	`string`	Text to display inside an information box after the user hovers the element for a small amount of time. This is only supported in the Editor UI.
`usage-hints`	`UIElements.UsageHints`	A combination of hint values that specify high-level intended usage patterns for the `VisualElement`. This property can only be set when the `VisualElement` is not yet part of a `Panel`. Once part of a `Panel`, this property becomes effectively read-only, and attempts to change it will throw an exception. The specification of proper `UsageHints` drives the system to make better decisions on how to process or accelerate certain operations based on the anticipated usage pattern. Note that those hints do not affect behavioral or visual results, but only affect the overall performance of the panel and the elements within. It’s advised to always consider specifying the proper `UsageHints`, but keep in mind that some `UsageHints` might be internally ignored under certain conditions (e.g. due to hardware limitations on the target platform).
`view-data-key`	`string`	Used for view data persistence, such as tree expanded states, scroll position, or zoom level. This key is used to save and load the view data from the view data store. If you don’t set this key, the persistence is disabled for the associated `VisualElement`. For more information, refer to View data persistence in the Unity Manual.

USS classes

The following table lists all the C# public property names and their related USS selector.

C# property	USS selector	Description
`ussClassName`	`.unity-help-box`	The USS class name for Elements of this type.
`topContainerUssClassName`	`.unity-help-box__top-container`	The USS class name for the top content container of this Elements type.
`bottomContainerUssClassName`	`.unity-help-box__bottom-container`	The USS class name for the bottom content container of this Elements type.
`linkUssClassName`	`.unity-help-box__link`	The USS class name for the action link for this Elements type.
`buttonUssClassName`	`.unity-help-box__button`	The USS class name for the action button of this Elements type.
`labelUssClassName`	`.unity-help-box__label`	The USS class name for labels in Elements of this type.
`iconUssClassName`	`.unity-help-box__icon`	The USS class name for images in Elements of this type.
`iconInfoUssClassName`	`.unity-help-box__icon--info`	The USS class name for the `HelpBoxMessageType.Info` state in Elements of this type.
`iconwarningUssClassName`	`.`	The USS class name for the `HelpBoxMessageType.Warning` state in Elements of this type.
`iconWarningUssClassName`	`.unity-help-box__icon--warning`	The USS class name for the `HelpBoxMessageType.Warning` state in Elements of this type.
`iconErrorUssClassName`	`.unity-help-box__icon--error`	The USS class name for the `HelpBoxMessageType.Error` state in Elements of this type.
`disabledUssClassName`	`.unity-disabled`	USS class name of local disabled elements.

You can also use the Matching Selectors section in the Inspector or the UI Toolkit Debugger to see which USS selectors affect the components of the VisualElement at every level of its hierarchy.

Additional resources

Work with text

Hash128Field

IMGUIContainer

Unity Manual