function drawLine(x1,y1,x2,y2,color,size){
var i;
var r=Math.floor(Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1)));
var theta=Math.atan((x2-x1)/(y2-y1));
if(((y2-y1)<0&&(x2-x1)>0)||((y2-y1)<0&&(x2-x1)<0)){theta=Math.PI+theta;}
var dx=Math.sin(theta);//alert(dx)
var dy=Math.cos(theta);
for(i=0;i<r;i++){
drawDot(x1+i*dx,y1+i*dy,color,size);
}
}
function drawDot(x,y,color,size){
var drawString="<table border='0' cellspacing=0 cellpadding=0><tr><td style='position: absolute; left: "+(x)+
"; top: "+(y)+";background-color: "+color+"' width="+size+" height="+size+"></td></tr></table>";
//document.getElementById('resultGraph').innerHTML=drawString;
document.write(drawString);
}
drawLine(20,20,300,20,"#0000cc",2);
document.write(drawString)就能画出线,document.getElementById('resultGraph').innerHTML=drawString只能画出一个点('resultGraph'是一个div)。
请达人指教,这是为嘛呢?