無法在Typescript中移除EventListener

Question

我正在嘗試刪除打字稿中的事件偵聽器。我在 if 語句中新增事件監聽器。在 else 語句中，我試圖刪除這些事件監聽器，但由於某種原因它沒有刪除它們。

僅供參考：我有一個按鈕，可以在其中設定布林值（movePick）。如果這是真的那麼我希望能夠移動我的物件。這就是建立事件偵聽器的地方。如果我再次單擊該按鈕，我將無法再移動該物件。這就是我嘗試刪除事件偵聽器的原因。

public moveObject(movePick: boolean, raycaster: THREE.Raycaster): void {
        const plane = new THREE.Plane();
        const pNormal = new THREE.Vector3(0, 1, 0); // plane's normal
        const planeIntersect = new THREE.Vector3(); // point of intersection with the plane
        const pIntersect = new THREE.Vector3(); // point of intersection with an object (plane's point)
        const shift = new THREE.Vector3(); // distance between position of an object and points of intersection with the object
        let isDragging = false;
        let dragObject: any;
        // events

        const pointermove = (event: PointerEvent) => {
            const rect = this.canvas.getBoundingClientRect();
            const x = event.clientX - rect.left
            const y = event.clientY - rect.top
            const pickPosition = { x: 0, y: 0 };
            pickPosition.x = (x / this.canvas.clientWidth) * 2 - 1;
            pickPosition.y = (y / this.canvas.clientHeight) * -2 + 1;
            raycaster.setFromCamera(pickPosition, this.camera);
            // console.log("movePICK IN POINTERMOVE",movePick)
            if (isDragging) {
                raycaster.ray.intersectPlane(plane, planeIntersect);
                dragObject.position.addVectors(planeIntersect, shift);
            }
        }

        const mousedown = () => {
            const intersects = raycaster.intersectObjects(this.scene.children);

            for (let i = 0; i < this.mesharr.length; i++) {
                if (intersects[0].object.name == this.mesharr[i].name && intersects[0].object.name != "Rail") {
                    pIntersect.copy(intersects[0].point);
                    plane.setFromNormalAndCoplanarPoint(pNormal, pIntersect);
                    shift.subVectors(intersects[0].object.position, intersects[0].point);
                    isDragging = true;
                    dragObject = intersects[0].object;
                }
            }
        }

        const pointerup = () => {
            isDragging = false;
            dragObject = null;
        }
        **if (movePick) {
            document.addEventListener("pointermove", pointermove);
            document.addEventListener("mousedown", mousedown);
            document.addEventListener("pointerup", pointerup);
        } else {
            document.removeEventListener("pointermove", pointermove);
            document.removeEventListener("mousedown", mousedown);
            document.removeEventListener("pointerup", pointerup);
        }**
    }

如果我在新增事件列表的同一個 if 語句中刪除事件列表，它們就會被刪除。但如果再次按一下該按鈕並進入 else 語句，則無法刪除它們。我也在 stackoverflow 中嘗試了幾種解決方案，但都不起作用。

Answer 1

將事件實例儲存到類別欄位中，然後在removeEventListener中呼叫該實例，例如。

document.removeEventListener("pointermove", this.savedpointermove);

現在應該可以了