這是我的代碼,我想用四個箭頭鍵盤移動圖片(圖片1),畫一些線條作爲背景區域,圖片移動1s一次,但我遇到了我不能移動PIC1,誰可以告訴我問題,爲什麼它不工作爲什麼鍵盤聽者不工作
<script type="text/javascript">
var canvas = document.getElementById("painting");
//canvas.addEventListener("keydown", doKeyDown, true);
var context2D = canvas.getContext("2d");
var pic = new Image();
var pic1=new Image();
var X=0,Y=200;
var X1=200,Y1=200;
pic.src = "music.jpg";
pic1.src = "qingwa.jpg";
function drawline()
{
context2D.moveTo(0,100);
context2D.lineTo(35,100);
context2D.lineTo(35,60);
context2D.lineTo(85,60);
context2D.lineTo(85,100);
context2D.lineTo(155,100);
context2D.lineTo(155,60);
context2D.lineTo(205,60);
context2D.lineTo(205,100);
context2D.lineTo(275,100);
context2D.lineTo(275,60);
context2D.lineTo(325,60);
context2D.lineTo(325,100);
context2D.lineTo(395,100);
context2D.lineTo(395,60);
context2D.lineTo(445,60);
context2D.lineTo(445,100);
context2D.lineTo(515,100);
context2D.lineTo(515,60);
context2D.lineTo(565,60);
context2D.lineTo(565,100);
context2D.lineTo(600,100);
context2D.stroke();
}
function doKeyDown(e)
{
switch (e.keyCode)
{
// the up key
case 38:
Y1 = Y1 - 10;
break;
//the down key
case 40:
Y1 = Y1 + 10;
break;
//the left key
case 37:
X1 = X1 - 10;
break;
//the right key
case 39:
X1 = X1 + 10;
break;
}
}
function drawfrogger()
{
context2D.drawImage(pic1,X1,Y1);
}
function draw()
{
context2D.clearRect(0,0,600,600);
context2D.save();
context2D.drawImage(pic,X,Y);
drawfrogger();
drawline();
context2D.restore(); //繪製結束以後,恢復畫筆狀態
if(X>600)
X = 0;
X = X + 100;
}
setInterval(draw, 1000);
</script>
增加了工作的jsfiddle ... –