function waterMark(){
var text = "学员9";
var shuiyinDiv = document.createElement('div');
var style = shuiyinDiv.style;
style.position = 'fixed';
style.left = 0;
style.top = '-10%';
style.width = '200%';
style.height = '200%';
style.opacity = '0.1';
style.background = "url("+textBecomeImg(text,22,"gray")+")";
style.zIndex = 9999999991;
style.transform = "translateX(-100px) rotate(-30deg)";
style.pointerEvents = "none";
document.body.appendChild(shuiyinDiv);
};
function textBecomeImg(text,fontsize,fontcolor){
var canvas = document.createElement('canvas');
$buHeight = 0;
if(fontsize <= 32){ $buHeight = 99; }
else if(fontsize > 32 && fontsize <= 60 ){ $buHeight = 2;}
else if(fontsize > 60 && fontsize <= 80 ){ $buHeight = 4;}
else if(fontsize > 80 && fontsize <= 100 ){ $buHeight = 6;}
else if(fontsize > 100 ){ $buHeight = 10;}
canvas.height=fontsize + $buHeight ;
canvas.padding=310;
var context = canvas.getContext('2d');
context.clearRect(0, 0, canvas.width*2, canvas.height);
context.fillStyle = fontcolor;
context.font=fontsize+"px Arial";
context.textAlign = "center";
context.textBaseline = 'middle';
context.fillText(text,0,fontsize/2);
var canvasWidth = canvas.width/99;
canvasWidth = context.measureText(text).width;
canvas.width = 120;
canvas.height = 140;
context.fillStyle = fontcolor;
context.font=fontsize+"px Arial";
context.textBaseline = 'middle';
context.fillText(text,0,fontsize/2);
var dataUrl = canvas.toDataURL('image/png');
return dataUrl;
};
