pagewatermark_canvas.js
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if (window.location.search.indexOf("?") == 0 && window.location.search.indexOf("=") > 1
&& window.location.search.indexOf("watermark_txt") != -1) {
var markUrl = new Object();
markUrl.watermark_txt=getQueryString("watermark_txt");
watermark(markUrl);
}else{
if(typeof(mark) != "undefined"){
watermark(mark);
}
}
function getQueryString(key){
var reg = new RegExp("(^|&)"+key+"=([^&]*)(&|$)");
var result = window.location.search.substr(1).match(reg);
return result?decodeURIComponent(result[2]):null;
}
function watermark(settings,$obj) {
var length = settings.watermark_txt.length;
var can = document.createElement('canvas');
var body = document.body;
body.appendChild(can);
can.width=360; //画布的宽
can.height=300;//画布的高度
can.style.display='none';
var cans = can.getContext('2d');
cans.rotate(-40 * Math.PI / 180); //画布里面文字的旋转角度
cans.font = "22px 黑体"; //画布里面文字的字体
cans.fillStyle = "#f2f2f2";//画布里面文字的颜色
//cans.fillRect(0, 0, can.width, can.height);
cans.translate(-150, 80);
cans.fillText(settings.watermark_txt,can.width -length * 11 ,can.height/2 + 10); //画布里面文字的间距比例
if($obj){
$obj.style.backgroundImage="url("+can.toDataURL("image/png")+")";
}else{
body.style.backgroundImage="url("+can.toDataURL("image/png")+")"; //把画布插入到body中
}
}