javascript - 未捕获的类型错误：仅在主页上无法读取 null 的属性“addEventListener”

Question

我只在我的主页上收到以下错误，它在其他任何地方都有效。

未捕获的类型错误：无法读取 null 的属性“addEventListener”

js文件代码如下。这是全屏下拉搜索。

(function() {
    var triggerBttn = document.getElementById( 'trigger-overlay' ),
        overlay = document.querySelector( 'div.overlay' ),
        closeBttn = overlay.querySelector( 'button.overlay-close' );
        transEndEventNames = {
            'WebkitTransition': 'webkitTransitionEnd',
            'MozTransition': 'transitionend',
            'OTransition': 'oTransitionEnd',
            'msTransition': 'MSTransitionEnd',
            'transition': 'transitionend'
        },
        transEndEventName = transEndEventNames[ Modernizr.prefixed( 'transition' ) ],
        support = { transitions : Modernizr.csstransitions };

    function toggleOverlay() {
        if( classie.has( overlay, 'open' ) ) {
            classie.remove( overlay, 'open' );
            classie.add( overlay, 'close' );
            var onEndTransitionFn = function( ev ) {
                if( support.transitions ) {
                    if( ev.propertyName !== 'visibility' ) return;
                    this.removeEventListener( transEndEventName, onEndTransitionFn );
                }
                classie.remove( overlay, 'close' );
            };
            if( support.transitions ) {
                overlay.addEventListener( transEndEventName, onEndTransitionFn );
            }
            else {
                onEndTransitionFn();
            }
        }
        else if( !classie.has( overlay, 'close' ) ) {
            classie.add( overlay, 'open' );
        }
    }
    triggerBttn.addEventListener( 'click', toggleOverlay );
    closeBttn.addEventListener( 'click', toggleOverlay );
})();

有人可以帮我解决这个问题吗？提前致谢。

标签： javascript