ScrollView 组件参考

[kingskys]

URL : https://github.com/cocos-creator/creator-docs/blob/master/zh/ui-system/components/editor/scrollview.md

问题：ScrollView 滚动事件回调接收到的是数字，然而EventType里没有数字的，只有字符串的。

下面是查到的出问题的原代码：

// ScrollView
protected _dispatchEvent (event: string) {
        if (event === EventType.SCROLL_ENDED) {
            this._scrollEventEmitMask = 0;
        } else if (event === EventType.SCROLL_TO_TOP
            || event === EventType.SCROLL_TO_BOTTOM
            || event === EventType.SCROLL_TO_LEFT
            || event === EventType.SCROLL_TO_RIGHT) {
            const flag = (1 << eventMap[event]);
            if (this._scrollEventEmitMask & flag) {
                return;
            } else {
                this._scrollEventEmitMask |= flag;
            }
        }

        ComponentEventHandler.emitEvents(this.scrollEvents, this, eventMap[event]);
        this.node.emit(event, this);
    }

// 发送的 eventMap[event] 是数字

const eventMap = {
    'scroll-to-top': 0,
    'scroll-to-bottom': 1,
    'scroll-to-left': 2,
    'scroll-to-right': 3,
    scrolling: 4,
    'bounce-bottom': 6,
    'bounce-left': 7,
    'bounce-right': 8,
    'bounce-top': 5,
    'scroll-ended': 9,
    'touch-up': 10,
    'scroll-ended-with-threshold': 11,
    'scroll-began': 12,
};

// cc.d.ts 里 ScrollView 对应的 EventType enum 都是字符串的，没有数字的，所以匹配不上。

export enum _cocos_ui_scroll_view__EventType {
    /**
     * @en
     * The event emitted when ScrollView scroll to the top boundary of inner container.
     *
     * @zh
     * 滚动视图滚动到顶部边界事件。
     */
    SCROLL_TO_TOP = "scroll-to-top",
    /**
     * @en
     * The event emitted when ScrollView scroll to the bottom boundary of inner container.
     *
     * @zh
     * 滚动视图滚动到底部边界事件。
     */
    SCROLL_TO_BOTTOM = "scroll-to-bottom",
    /**
     * @en
     * The event emitted when ScrollView scroll to the left boundary of inner container.
     *
     * @zh
     * 滚动视图滚动到左边界事件。
     */
    SCROLL_TO_LEFT = "scroll-to-left",
    /**
     * @en
     * The event emitted when ScrollView scroll to the right boundary of inner container.
     *
     * @zh
     * 滚动视图滚动到右边界事件。
     */
    SCROLL_TO_RIGHT = "scroll-to-right",
    /**
     * @en
     * The event emitted when ScrollView scroll began.
     *
     * @zh
     * 滚动视图滚动开始时发出的事件。
     */
    SCROLL_BEGAN = "scroll-began",
    /**
     * @en
     * The event emitted when ScrollView auto scroll ended.
     *
     * @zh
     * 滚动视图滚动结束的时候发出的事件。
     */
    SCROLL_ENDED = "scroll-ended",
    /**
     * @en
     * The event emitted when ScrollView scroll to the top boundary of inner container and start bounce.
     *
     * @zh
     * 滚动视图滚动到顶部边界并且开始回弹时发出的事件。
     */
    BOUNCE_TOP = "bounce-top",
    /**
     * @en
     * The event emitted when ScrollView scroll to the bottom boundary of inner container and start bounce.
     *
     * @zh
     * 滚动视图滚动到底部边界并且开始回弹时发出的事件。
     */
    BOUNCE_BOTTOM = "bounce-bottom",
    /**
     * @en
     * The event emitted when ScrollView scroll to the left boundary of inner container and start bounce.
     *
     * @zh
     * 滚动视图滚动到左边界并且开始回弹时发出的事件。
     */
    BOUNCE_LEFT = "bounce-left",
    /**
     * @en
     * The event emitted when ScrollView scroll to the right boundary of inner container and start bounce.
     *
     * @zh
     * 滚动视图滚动到右边界并且开始回弹时发出的事件。
     */
    BOUNCE_RIGHT = "bounce-right",
    /**
     * @en
     * The event emitted when ScrollView is scrolling.
     *
     * @zh
     * 滚动视图正在滚动时发出的事件。
     */
    SCROLLING = "scrolling",
    /**
     * @en
     * The event emitted when ScrollView auto scroll ended with a threshold.
     *
     * @zh
     * 滚动视图自动滚动快要结束的时候发出的事件。
     */
    SCROLL_ENG_WITH_THRESHOLD = "scroll-ended-with-threshold",
    /**
     * @en
     * The event emitted when user release the touch.
     *
     * @zh
     * 当用户松手的时候会发出一个事件。
     */
    TOUCH_UP = "touch-up"
}

[MrKylinGithub]

谢谢反馈，已转发到引擎仓库：cocos/cocos-engine#17089