Scroll
NOTE This component is supported since API version 7. Updates will be marked with a superscript to indicate their earliest API version.
The <Scroll> component scrolls the content when the layout size of a component exceeds the viewport of its parent component.
Required Permissions
None
Child Components
This component supports only one child component.
APIs
Scroll(scroller?: Scroller)
Attributes
| Name | Type | Default Value | Description |
|---|---|---|---|
| scrollable | ScrollDirection | ScrollDirection.Vertical | Scroll method. |
| scrollBar | BarState | Auto | Scroll bar status. |
| scrollBarColor | Color | - | Color of the scroll bar. |
| scrollBarWidth | Length | - | Width of the scrollbar. |
- ScrollDirection
| Name | Description |
|---|---|
| Horizontal | Only horizontal scrolling is supported. |
| Vertical | Only vertical scrolling is supported. |
| None | Scrolling is disabled. |
Scroller
Controller of the scrollable container component. You can bind this component to the container component and use it to control the scrolling of the container component. Currently, this component can be bound to the <List> and <Scroll> components.
Objects to Import
scroller: Scroller = new Scroller()
scroller.scrollTo
scrollTo(value: { xOffset: number | string, yOffset: number | string, animation?: { duration: number, curve: Curve } }): void
Scrolls to the specified position.
- Parameters
| Name | Type | Mandatory | Default Value | Description |
|---|---|---|---|---|
| xOffset | Length | Yes | - | Horizontal scrolling offset. |
| yOffset | Length | Yes | - | Vertical scrolling offset. |
| animation | { duration: number, curve: Curve | CubicBezier | SpringCurve } |
No | Animation configuration, which includes the following: - duration: scrolling duration. - curve: scrolling curve. |
scroller.scrollEdge
scrollEdge(value: Edge): void
Scrolls to the edge of the container.
- Parameters
| Name | Type | Mandatory | Default Value | Description |
|---|---|---|---|---|
| value | Edge | Yes | - | Edge position to scroll to. |
scroller.scrollPage
scrollPage(value: { next: boolean, direction?: Axis }): void
Scrolls to the next or previous page.
- Parameters
| Name | Type | Mandatory | Default Value | Description |
|---|---|---|---|---|
| next | boolean | Yes | - | Whether to turn to the next page. The value true means to scroll to the next page, and the value false means to scroll to the previous page. |
scroller.currentOffset
scroller.currentOffset(): Object
Obtains the scrolling offset.
- Return values
| Type | Description |
|---|---|
| { xOffset: number, yOffset: number } |
xOffset: horizontal scrolling offset. yOffset: vertical scrolling offset. |
scroller.scrollToIndex
scroller.scrollToIndex(value: number): void
Scrolls to the specified index.
- Parameters
| Name | Type | Mandatory | Default Value | Description |
|---|---|---|---|---|
| value | number | Yes | - | Index of the item to be scrolled to in the list. |
Events
| Name | Description |
|---|---|
| onScroll(xOffset: number, yOffset: number) => void | Invoked to return the horizontal and vertical offsets during scrolling when the specified scroll event occurs. |
| onScrollEdge(side: Edge) => void | Callback for the event of scrolling to the edge. |
| onScrollEnd() => void | Invoked when scrolling stops. |
Example
@Entry
@Component
struct ScrollExample {
scroller: Scroller = new Scroller()
private arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
build() {
Stack({ alignContent: Alignment.TopStart }) {
Scroll(this.scroller) {
Column() {
ForEach(this.arr, (item) => {
Text(item.toString())
.width('90%').height(150).backgroundColor(0xFFFFFF)
.borderRadius(15).fontSize(16).textAlign(TextAlign.Center)
.margin({ top: 10 })
}, item => item)
}.width('100%')
}
.scrollable(ScrollDirection.Vertical).scrollBar(BarState.On)
.scrollBarColor(Color.Gray).scrollBarWidth(30)
.onScroll((xOffset: number, yOffset: number) => {
console.info(xOffset + ' ' + yOffset)
})
.onScrollEdge((side: Edge) => {
console.info('To the edge')
})
.onScrollEnd(() => {
console.info('Scroll Stop')
})
Button('scroll 100')
.onClick(() => {// Click to scroll down 100.0.
this.scroller.scrollTo({ xOffset: 0, yOffset: this.scroller.currentOffset().yOffset + 100 })
})
.margin({ top: 10, left: 20 })
Button('back top')
.onClick(() => {// Click to go back to the top.
this.scroller.scrollEdge(Edge.Top)
})
.margin({ top: 60, left: 20 })
Button('next page')
.onClick(() => {// Click to scroll down to the bottom.
this.scroller.scrollPage({ next: true })
})
.margin({ top: 110, left: 20 })
}.width('100%').height('100%').backgroundColor(0xDCDCDC)
}
}
