1

我有一个 TypeScript 类，它看起来像这样：

class MyClass {

    let canvas: any;

    constructor(canvas: any) {

        this.canvas = canvas;

        this.canvas.requestPointerLock = this.canvas.requestPointerLock;
        document.exitPointerLock = document.exitPointerLock;

        this.canvas.onclick = this._mouseClickHandler.bind(this);
        document.addEventListener('pointerlockchange', this._togglePointerLock.bind(this), false);
    }

    private _mouseClickHandler(event: MouseEvent): void {
        this.canvas.requestPointerLock();
    }

    private _togglePointerLock() {
        if (document.pointerLockElement === this.canvas) {
            console.info('Locked mouse pointer to canvas.');
            document.addEventListener('mousemove', this._handleMouseMovement.bind(this), false);
        } else {
            console.info('Unlocked mouse pointer from canvas.');
            // THIS DOES NOT WORK
            document.removeEventListener('mousemove', this._handleMouseMovement.bind(this), false);
        }
    }

    private _handleMouseMovement(event: MouseEvent) {
        console.log('Mouse moved to: ', event.movementX, event.movementY);
    }
}

基本上，代码应该_handleMouseMovement在鼠标锁定到画布后注册事件侦听器，并在锁定被移除后将其移除。

锁定确实有效。它激活了位置记录，_handleMouseMovement但是一旦我通过删除锁定，ESC我确实收到消息Unlocked mouse pointer from canvas.所以_handleMouseMovement没有删除并且位置记录继续。

我认为我确实注意不要注册匿名函数，这可能是导致此类问题的原因。所以我想知道还有什么可能导致这种行为。

4

1 回答 1

7

.bind创建一个新函数。所以你的添加和删除不是针对同一个功能的。

使固定

不要使用.bind，而是使用箭头函数：

private _handleMouseMovement = (event: MouseEvent) => {
    console.log('Mouse moved to: ', event.movementX, event.movementY);
}
于 2018-05-21T01:40:09.053 回答