javascript - 仅在全屏模式下显示页面滚动

Question

我有以下 JS，它曾经在单击链接后使页面全屏显示:

<a href="javascript:void(0)" onclick="javascript:toggleFullScreen()"></a>

// mozfullscreenerror event handler
function errorHandler() {
   alert('mozfullscreenerror');
}
document.documentElement.addEventListener('mozfullscreenerror', errorHandler, false);

// toggle full screen
function toggleFullScreen() {
  if (!document.fullscreenElement &&    // alternative standard method
      !document.mozFullScreenElement && !document.webkitFullscreenElement) {  // current working methods
    if (document.documentElement.requestFullscreen) {
      document.documentElement.requestFullscreen();
    } else if (document.documentElement.mozRequestFullScreen) {
      document.documentElement.mozRequestFullScreen();
    } else if (document.documentElement.webkitRequestFullscreen) {
      document.documentElement.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
    }
  } else {
    if (document.cancelFullScreen) {
      document.cancelFullScreen();
    } else if (document.mozCancelFullScreen) {
      document.mozCancelFullScreen();
    } else if (document.webkitCancelFullScreen) {
      document.webkitCancelFullScreen();
    }
  }
}

// keydown event handler
document.addEventListener('keydown', function(e) {
  if (e.keyCode == 13 || e.keyCode == 70) { // F or Enter key
    toggleFullScreen();
  }
}, false);

有没有办法让页面滚动(溢出)仅在全屏模式下可见，并且当用户通过再次单击相同链接或通过其他方式取消全屏时，溢出会隐藏？

Answer 1

您可以只使用一个类来表示“无溢出”，反之亦然。然后将它应用到你的函数中，就像这样:

if (!document.fullscreenElement && !document.mozFullScreenElement && !document.webkitFullscreenElement) {  // current working methods
        document.body.className = document.body.className.replace(' no-scroll', '');
        ...
} else {
    document.body.className += " no-scroll";

参见this working example使用以下方法“切换”类以“打开/关闭”滚动

// add/remove no scroll class to body
function toggleNoScroll(off) {
    //  test if already exist:
    var a = Array.prototype.indexOf.call(document.body.classList, 'no-scroll') + 1;
    //  remove if does exist, so as not to double up
    document.body.className = document.body.className.replace(' no-scroll', '');
    //  add only if off IS False OR off is empty & it did not previously exist (thus "toggle")
    if (off === false || (off !== true && !a)) document.body.className += " no-scroll";
    return document.body.classList;
}

那么我有:

if (!document.fullscreenElement && !document.mozFullScreenElement && !document.webkitFullscreenElement) {
    toggleNoScroll(true);
...
else {
    toggleNoScroll(false);