我的想法是这样的。但是不行。。出了什么问题？应该怎样弄？
var imgId=0;//
function draw(){
drawImg()
imgId++;
}
function drawImg(){
cxt.clearRect(0,0,500,500)
var img=new Image();
img.src=imgId+'.png';
cxt.drawImage(img,0,0);
}
然后<input type=button value="start" onClick="draw()">
第1个回答 2013-08-23
可以参考JavaScript Image Preloader 。
我写了一个代码，你看一下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " ">
<html xmlns=" ">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>
<body onload=preloader()>
<canvas id="pad" width="100%" height="100%"></canvas>
<script language="JavaScript">
var ctx=document.getElementById('pad').getContext('2d');
var imageObj=new Image();
preloader();
imageObj.onload=function(){
for(var i=0;i<6;i++)
ctx.drawImage(imageObj,0+i*20,0+1*20,80,40);
}
function preloader()
{
// counter
var i = 0;
// create object
//imageObj = new Image();
// set image list
images = new Array();
images[0]="images/0.jpg"
images[1]="images/1.jpg"
images[2]="images/2.jpg"
images[3]="images/3.jpg"
images[4]="images/4.jpg"
images[5]="images/5.jpg"
// start preloading
for(i=0; i<=3; i++)
{
imageObj.src=images[i];
}
}
</script>
</body>
</html>
我写了一个代码，你看一下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " ">
<html xmlns=" ">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>
<body onload=preloader()>
<canvas id="pad" width="100%" height="100%"></canvas>
<script language="JavaScript">
var ctx=document.getElementById('pad').getContext('2d');
var imageObj=new Image();
preloader();
imageObj.onload=function(){
for(var i=0;i<6;i++)
ctx.drawImage(imageObj,0+i*20,0+1*20,80,40);
}
function preloader()
{
// counter
var i = 0;
// create object
//imageObj = new Image();
// set image list
images = new Array();
images[0]="images/0.jpg"
images[1]="images/1.jpg"
images[2]="images/2.jpg"
images[3]="images/3.jpg"
images[4]="images/4.jpg"
images[5]="images/5.jpg"
// start preloading
for(i=0; i<=3; i++)
{
imageObj.src=images[i];
}
}
</script>
</body>
</html>
