1e41f4b71Sopenharmony_ci# Common Event Callback
2e41f4b71Sopenharmony_ci
3e41f4b71Sopenharmony_ci>**NOTE**
4e41f4b71Sopenharmony_ci>
5e41f4b71Sopenharmony_ci>The initial APIs of this module are supported since API version 12. Newly added APIs will be marked with a superscript to indicate their earliest API version.
6e41f4b71Sopenharmony_ci
7e41f4b71Sopenharmony_ci## UICommonEvent
8e41f4b71Sopenharmony_ciImplements a common event callback. If the input parameter of an API is **undefined**, the corresponding event callback is reset.
9e41f4b71Sopenharmony_ci### setOnClick
10e41f4b71Sopenharmony_ci
11e41f4b71Sopenharmony_cisetOnClick(callback: Callback\<ClickEvent> | undefined): void
12e41f4b71Sopenharmony_ci
13e41f4b71Sopenharmony_ciSet the callback for the [click event](./ts-universal-events-click.md#click-event).
14e41f4b71Sopenharmony_ci
15e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
16e41f4b71Sopenharmony_ci
17e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
18e41f4b71Sopenharmony_ci
19e41f4b71Sopenharmony_ci**Parameters**
20e41f4b71Sopenharmony_ci
21e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
22e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
23e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)<[ClickEvent](./ts-universal-events-click.md#clickevent)> \| undefined | Yes  | Callback for the click event. |
24e41f4b71Sopenharmony_ci
25e41f4b71Sopenharmony_ci### setOnTouch
26e41f4b71Sopenharmony_ci
27e41f4b71Sopenharmony_cisetOnTouch(callback: Callback\<TouchEvent> | undefined): void
28e41f4b71Sopenharmony_ci
29e41f4b71Sopenharmony_ciSets the callback for the [touch event](./ts-universal-events-touch.md#touch-event).
30e41f4b71Sopenharmony_ci
31e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
32e41f4b71Sopenharmony_ci
33e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
34e41f4b71Sopenharmony_ci
35e41f4b71Sopenharmony_ci**Parameters**
36e41f4b71Sopenharmony_ci
37e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
38e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
39e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)<[TouchEvent](./ts-universal-events-touch.md#touchevent)> \| undefined | Yes  | Callback for the touch event. |
40e41f4b71Sopenharmony_ci
41e41f4b71Sopenharmony_ci
42e41f4b71Sopenharmony_ci### setOnAppear
43e41f4b71Sopenharmony_ci
44e41f4b71Sopenharmony_cisetOnAppear(callback: Callback\<void> | undefined): void
45e41f4b71Sopenharmony_ci
46e41f4b71Sopenharmony_ciSets the callback for the [onAppear](./ts-universal-events-show-hide.md#onappear) event.
47e41f4b71Sopenharmony_ci
48e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
49e41f4b71Sopenharmony_ci
50e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
51e41f4b71Sopenharmony_ci
52e41f4b71Sopenharmony_ci**Parameters**
53e41f4b71Sopenharmony_ci
54e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
55e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
56e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)\<void> \| undefined | Yes  | Callback for the **onAppear** event. |
57e41f4b71Sopenharmony_ci
58e41f4b71Sopenharmony_ci
59e41f4b71Sopenharmony_ci### setOnDisappear
60e41f4b71Sopenharmony_ci
61e41f4b71Sopenharmony_cisetOnDisappear(callback: Callback\<void> | undefined): void
62e41f4b71Sopenharmony_ci
63e41f4b71Sopenharmony_ciSets the callback for the [onDisappear](./ts-universal-events-show-hide.md#ondisappear) event.
64e41f4b71Sopenharmony_ci
65e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
66e41f4b71Sopenharmony_ci
67e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
68e41f4b71Sopenharmony_ci
69e41f4b71Sopenharmony_ci**Parameters**
70e41f4b71Sopenharmony_ci
71e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
72e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
73e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)\<void> \| undefined | Yes  | Callback for the **onDisappear** event. |
74e41f4b71Sopenharmony_ci
75e41f4b71Sopenharmony_ci### setOnKeyEvent
76e41f4b71Sopenharmony_ci
77e41f4b71Sopenharmony_cisetOnKeyEvent(callback: Callback\<KeyEvent> | undefined): void
78e41f4b71Sopenharmony_ci
79e41f4b71Sopenharmony_ciSets the callback for the [key event](./ts-universal-events-key.md#key-event).
80e41f4b71Sopenharmony_ci
81e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
82e41f4b71Sopenharmony_ci
83e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
84e41f4b71Sopenharmony_ci
85e41f4b71Sopenharmony_ci**Parameters**
86e41f4b71Sopenharmony_ci
87e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
88e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
89e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)<[KeyEvent](./ts-universal-events-key.md#keyevent)> \| undefined | Yes  | Callback for the key event. |
90e41f4b71Sopenharmony_ci
91e41f4b71Sopenharmony_ci### setOnFocus
92e41f4b71Sopenharmony_ci
93e41f4b71Sopenharmony_cisetOnFocus(callback:  Callback\<void> | undefined): void
94e41f4b71Sopenharmony_ci
95e41f4b71Sopenharmony_ciSets the callback for the [onFocus](./ts-universal-focus-event.md#onfocus) event.
96e41f4b71Sopenharmony_ci
97e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
98e41f4b71Sopenharmony_ci
99e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
100e41f4b71Sopenharmony_ci
101e41f4b71Sopenharmony_ci**Parameters**
102e41f4b71Sopenharmony_ci
103e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
104e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
105e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)\<void> \| undefined | Yes  | Callback for the **onFocus** event. |
106e41f4b71Sopenharmony_ci
107e41f4b71Sopenharmony_ci### setOnBlur
108e41f4b71Sopenharmony_ci
109e41f4b71Sopenharmony_cisetOnBlur(callback: Callback\<void> | undefined): void
110e41f4b71Sopenharmony_ci
111e41f4b71Sopenharmony_ciSets the callback for the [onBlur](./ts-universal-focus-event.md#onblur) event.
112e41f4b71Sopenharmony_ci
113e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
114e41f4b71Sopenharmony_ci
115e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
116e41f4b71Sopenharmony_ci
117e41f4b71Sopenharmony_ci**Parameters**
118e41f4b71Sopenharmony_ci
119e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
120e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
121e41f4b71Sopenharmony_ci| callback  | [Callback](./ts-types.md#callback12)\<void> \| undefined | Yes  | Callback for the **onBlur** event. |
122e41f4b71Sopenharmony_ci
123e41f4b71Sopenharmony_ci### setOnHover
124e41f4b71Sopenharmony_ci
125e41f4b71Sopenharmony_cisetOnHover(callback: HoverCallback | undefined): void
126e41f4b71Sopenharmony_ci
127e41f4b71Sopenharmony_ciSets the callback for the [onHover](./ts-universal-mouse-key.md#onhover) event.
128e41f4b71Sopenharmony_ci
129e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
130e41f4b71Sopenharmony_ci
131e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
132e41f4b71Sopenharmony_ci
133e41f4b71Sopenharmony_ci**Parameters**
134e41f4b71Sopenharmony_ci
135e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
136e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
137e41f4b71Sopenharmony_ci| callback  | [HoverCallback](./ts-types.md#hovercallback12)  \| undefined | Yes  | Callback for the **onHover** event. |
138e41f4b71Sopenharmony_ci
139e41f4b71Sopenharmony_ci### setOnMouse
140e41f4b71Sopenharmony_ci
141e41f4b71Sopenharmony_cisetOnMouse(callback: Callback\<MouseEvent> | undefined): void
142e41f4b71Sopenharmony_ci
143e41f4b71Sopenharmony_ciSets the callback for the [onMouse](./ts-universal-mouse-key.md#onmouse) event.
144e41f4b71Sopenharmony_ci
145e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
146e41f4b71Sopenharmony_ci
147e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
148e41f4b71Sopenharmony_ci
149e41f4b71Sopenharmony_ci**Parameters**
150e41f4b71Sopenharmony_ci
151e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
152e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
153e41f4b71Sopenharmony_ci| callback  |  [Callback](./ts-types.md#callback12)<[MouseEvent](./ts-universal-mouse-key.md#mouseevent)> \| undefined | Yes  | Callback for the **onMouse** event. |
154e41f4b71Sopenharmony_ci
155e41f4b71Sopenharmony_ci### setOnSizeChange
156e41f4b71Sopenharmony_ci
157e41f4b71Sopenharmony_cisetOnSizeChange(callback: SizeChangeCallback | undefined): void
158e41f4b71Sopenharmony_ci
159e41f4b71Sopenharmony_ciSets the callback for the [onSizeChange](./ts-universal-component-size-change-event.md#onsizechange) event.
160e41f4b71Sopenharmony_ci
161e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
162e41f4b71Sopenharmony_ci
163e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
164e41f4b71Sopenharmony_ci
165e41f4b71Sopenharmony_ci**Parameters**
166e41f4b71Sopenharmony_ci
167e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
168e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
169e41f4b71Sopenharmony_ci| callback  | [SizeChangeCallback](./ts-universal-component-size-change-event.md#sizechangecallback)   \| undefined | Yes  | Callback for the **onSizeChange** event. |
170e41f4b71Sopenharmony_ci
171e41f4b71Sopenharmony_ci### setOnVisibleAreaApproximateChange
172e41f4b71Sopenharmony_ci
173e41f4b71Sopenharmony_cisetOnVisibleAreaApproximateChange(options: VisibleAreaEventOptions, event: VisibleAreaChangeCallback | undefined): void
174e41f4b71Sopenharmony_ci
175e41f4b71Sopenharmony_ciSets the [onVisibleAreaChange](./ts-universal-component-visible-area-change-event.md#onvisibleareachange) callback that limits the callback interval.
176e41f4b71Sopenharmony_ci
177e41f4b71Sopenharmony_ci**Atomic service API**: This API can be used in atomic services since API version 12.
178e41f4b71Sopenharmony_ci
179e41f4b71Sopenharmony_ci**System capability**: SystemCapability.ArkUI.ArkUI.Full
180e41f4b71Sopenharmony_ci
181e41f4b71Sopenharmony_ci**Parameters**
182e41f4b71Sopenharmony_ci
183e41f4b71Sopenharmony_ci| Name | Type  | Mandatory | Description                      |
184e41f4b71Sopenharmony_ci| ------ | ------ | ---- | -------------------------- |
185e41f4b71Sopenharmony_ci| options  | [VisibleAreaEventOptions](./ts-types.md#visibleareaeventoptions12) | Yes  | Options of visible area changes. |
186e41f4b71Sopenharmony_ci| event  | [VisibleAreaChangeCallback](./ts-types.md#visibleareachangecallback12)   \| undefined | Yes  | Callback for the **onVisibleAreaChange** event. Called when the ratio of the component's visible area to its total area is greater than or less than the threshold. |
187e41f4b71Sopenharmony_ci
188e41f4b71Sopenharmony_ci>**NOTE**
189e41f4b71Sopenharmony_ci>
190e41f4b71Sopenharmony_ci> This callback is not a real-time callback. The actual callback interval may be different from the expected interval.
191e41f4b71Sopenharmony_ci> The interval between **onVisibleAreaChange** callbacks is greater than or equal to the expected update interval. If the expected interval set is too short, the actual callback interval is subject to the system load.
192