onkeyup和onkeydown没有抓到任何东西

Question

onkeyup和onkeydown没有抓到任何东西

Cya*_*ime 4 html javascript css html5 canvas

谁能告诉我发生了什么事？我的控制台没有抛出任何异常.

    function onKeyDown(){
                    var e = event.keyCode;

                    //if (e==87 /*w*/){
                        up = true;
                        throw('up'); 
                    //}

                    if (e==65 /*a*/){
                        left = true;
                    }

                    if (e==83 /*s*/){
                        down = true;
                    }

                    if (e==68 /*d*/){
                        right = true;
                    }
                }

                function onKeyUp(){
                    var e = event.keyCode;

                    //if (e==87 /*w*/){
                        up = false;
                        throw('up'); 
                    //}

                    if (e==65 /*a*/){
                        left = false;
                    }

                    if (e==83 /*s*/){
                        down = false;
                    }

                    if (e==68 /*d*/){
                        right = false;
                    }
                }

Okay, so that was the javascript, and this is the html:

    <body>
            <input id="ss" type="button" value="start/stop" />
            <div id="container" style="border:1px solid; cursor:none; width:480px; height:320px;">
                <canvas id="canvas" width="480" height="320"  onkeyup="onKeyUp();" onkeydown="onKeydown();">
                    Canvas not displaying.
                </canvas>
            </div>
        </body>



Edit: current code:

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window.onload = function(){init(); };

function init(){
                initSettings();
                initImages();

                document.getElementById('canvas').onkeydown = function(event) {
                    var e = event.keyCode;

                    //if (e==87 /*w*/){
                        up = true;
                        throw('up'); 
                    //}

                    if (e==65 /*a*/){
                        left = true;
                    }

                    if (e==83 /*s*/){
                        down = true;
                    }

                    if (e==68 /*d*/){
                        right = true;
                    }
                }

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Answer 1

thi*_*dot 16

你应该做这样的事情:

document.onkeydown = function(event) {
    ...
}
document.onkeyup = function(event) {
    ...
}

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并摆脱:

onkeyup="onKeyUp();" onkeydown="onKeydown();"

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我制作的快速测试页面有效:

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<script type="text/javascript">
document.onkeydown = function(event) {
 event = event || window.event;

 var e = event.keyCode;

 //if (e==87 /*w*/){
  up = true;
  throw('up'); 
 //}

 if (e==65 /*a*/){
  left = true;
 }

 if (e==83 /*s*/){
  down = true;
 }

 if (e==68 /*d*/){
  right = true;
 }
}

document.onkeyup=function(event) {
 event = event || window.event;

 var e = event.keyCode;

 //if (e==87 /*w*/){
  up = false;
  throw('up'); 
 //}

 if (e==65 /*a*/){
  left = false;
 }

 if (e==83 /*s*/){
  down = false;
 }

 if (e==68 /*d*/){
  right = false;
 }
}
</script>
</head>

<body>
    <input id="ss" type="button" value="start/stop" />
    <div id="container" style="border:1px solid; cursor:none; width:480px; height:320px;">
        <canvas id="canvas" width="480" height="320">
            Canvas not displaying.
        </canvas>
    </div>
</body>

</html>

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或者在他的情况下`document.getElementById("canvas").onkeydown = ...`等,我猜？另外,不要忘记做`event = event || window.event;`每个处理程序中的第一件事(因此IE不会废弃.顺便说一下,我很确定他的原始代码会在其他所有内容中废弃.) (2认同)

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