scrollIntoView 未在触摸事件侦听器中执行答案

【问题标题】：scrollIntoView not executed in touch event listenerscrollIntoView 未在触摸事件侦听器中执行
【发布时间】：2020-12-03 10:19:51
【问题描述】：

我正在尝试制作垂直滑动，它可以在带有滚轮事件的桌面上运行，但 scrollIntoView 方法不会在触摸事件侦听器中执行。

这里是代码

let startClientY, endClientY;
    page.addEventListener("touchstart", (event) => {
        startClientY = event.touches[0].pageY;
    }, false);

    page.addEventListener("touchmove", (event) => {
        endClientY = event.touches[0].pageY;
    }, false);

    page.addEventListener("touchend", (event) => {
        let diff = startClientY - endClientY;
        if (diff < -35) {
            if( i !== 0 ) {
                slides[i - 1].scrollIntoView({
                    behavior: "smooth", block: "start"
                });
                i--;
                console.log('scroll top'); // this code is executed as well
            }
        } else if (diff > 35) {
            if( i < slides.length -1) {
                slides[i + 1].scrollIntoView({
                    behavior: "smooth", block: "start"
                });
                i++;
                console.log('scroll down'); // this code is executed
            }
        }
        startClientY = undefined;
        endClientY = undefined;
    }, false);

奇怪的一点是条件里面的控制台日志被执行，而scrollIntoView方法在eventListeners之外起作用

我错过了什么？

【问题讨论】：

标签： javascript scroll touch slide

【解决方案1】：

问题来自触摸事件侦听器中的 scrollIntoView 行为选项，我找到了另一种方法来实现我想要的。

let slideHeight = page.offsetHeight;
page.addEventListener("touchstart", function (event) {
startClientY = event.touches[0].pageY;
}, {
    capture: true,
    passive: true
});

page.addEventListener("touchmove", function (event) {
    endClientY = event.touches[0].pageY;
}, {
    capture: true,
    passive: true
});

page.addEventListener("touchend", (event) => {
    let diff = startClientY - endClientY;
    if (diff < -35) {
        if (i !== 0) {
            page.scrollBy(0, -slideHeight);
            i--;
        }
    } else if (diff > 35) {
        if (i < slides.length - 1) {
            page.scrollBy(0, slideHeight);
            i++;
        }
    }
    startClientY = undefined;
    endClientY = undefined;
}, {
    capture: true,
    passive: true
});

page 变量是我的幻灯片希望对您有所帮助！

【讨论】：