一、问题:
<!DOCTYPE html> <html> <body> <canvas id="myCanvas" width="500" height="500" style="border:1px solid #c3c3c3;"> Your browser does not support the canvas element. </canvas> <script type="text/javascript" > var c=document.getElementById("myCanvas"); var cxt=c.getContext("2d"); var img=new Image(); img.src="1.jpg"; cxt.drawImage(img,0,0,500,500); </script> </body> </html>
二、解决:
在11行处加onload事件
<!DOCTYPE html> <html> <body> <canvas id="myCanvas" width="500" height="500" style="border:1px solid #c3c3c3;"> Your browser does not support the canvas element. </canvas> <script type="text/javascript" > var c=document.getElementById("myCanvas"); var cxt=c.getContext("2d"); var img=new Image(); img.src="1.jpg"; img.onload=function(){ cxt.drawImage(img,0,0,500,500); } </script> </body> </html>
三、原因(考虑中):
drawImage的时候图片没有加载完