canvas之drawImage

deawImage三种调用方式

context.deawImage(image,dx,dy,dw,dh)

context.deawImage(image,dx,dy)

context.drawImage(image,sx,sy,sw,sh,dx,dy,dw,dh)

<input type="range">滑动杆

var canvas=document.getElementById("canvas")

var context=canvas.getContext("2d")

var image=new Image()

window.onload=function(){

    image.onload=function(){

        context.deawImage(image,0,0,canvas.width,canvas.height)

    }

}