javascript - 如何创建仅在同时按下两个 'shift + left/right arrow' 键后触发的事件监听器？

Question

在下面的代码中，我遇到的问题是调用了 focusPosition 函数，但控制台没有记录所需的字符串:("shift + left/right arrow")

// Hold reference to the currently focused position
var currentPosition = 0;

// Maximum position we can navigate to is the last item in the summary list
var maxFocusablePosition = summaryList.length - 1;

// Utility function to focus a given position value
function focusPosition(position) {
    console.log("focus position is called");
    $('#' + summaryList[position]).focus();
};

// Focus the first one by default       
focusPosition(currentPosition);

$(document).keydown(function (event) {  
    if (event.which === 37 && event.which === 16) { 
        currentPosition = (currentPosition > 0) ? parseInt(currentPosition) - 1 : maxFocusablePosition; 
        console.log(' shift + left');
    } 

    if (event.which === 39 && event.which === 16) {
        currentPosition = (currentPosition < maxFocusablePosition) ? parseInt(currentPosition) + 1 : 0; 
        console.log('shift + right');
    } 

    focusPosition(currentPosition); 
});

Answer 1

在which中查找箭头键，并查找event.shiftKey是否为真，以了解shift键是否按下。这就是修饰键与 keydown 事件配合使用的方式(有 shiftKey、ctrlKey、altKey 和 metaKey )。