在HTML5 canvas中创建关键事件的最好方法是什么？

问题描述

请建议为HTML5 canvas创建关键事件的最佳方法。我不喜欢任何图书馆，但如果你认为这是最好的方法，然后去回答它。提前感谢！

Please suggest the best way to create key events for HTML5 canvas. I don't prefer any library, but if you think that it's the best way then go answer it. Thanks in advance!

推荐答案

这将返回键码：

<canvas id="myCanvas" width="200" height="100" style="background:green"></canvas>
<script type="text/javascript">
window.addEventListener('keydown',this.check,false);

function check(e) {
    alert(e.keyCode);
}
</script>

如果您想根据键演示不同的操作：

If you would like a demonstration of different things being done based on key:

function check(e) {
    var code = e.keyCode;
    //Up arrow pressed
    if (code == 38)
        alert("You pressed the Up arrow key");
    else
        alert("You pressed some other key I don't really care about.");
}

或者如果你有一个很长的键列表，

Or if you have a long list of keys you'll be using, do it in a switch case:

function check(e) {
    var code = e.keyCode;
    switch (code) {
        case 37: alert("Left"); break; //Left key
        case 38: alert("Up"); break; //Up key
        case 39: alert("Right"); break; //Right key
        case 40: alert("Down"); break; //Down key
        default: alert(code); //Everything else
    }
}

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