vue项目页面添加水印
使用方法:在根组件中全局引入,watermark.set(“用户名”)
页面显示效果如下:
方法如下:
let watermark = {};
let setWatermark = (str) => {
let id = "1.23452384164.123412416";
if (document.getElementById(id) !== null) {
document.body.removeChild(document.getElementById(id));
}
//创建一个画布
let can = document.createElement("canvas");
//设置画布的长宽
can.width = 400;
can.height = 300;
let cans = can.getContext("2d");
//旋转角度
cans.rotate((-15 * Math.PI) / 180);
cans.font = "18px Vedana";
//设置填充绘画的颜色、渐变或者模式
cans.fillStyle = "rgba(200, 200, 200, 0.60)";
//设置文本内容的当前对齐方式
cans.textAlign = "center";
//设置在绘制文本时使用的当前文本基线
cans.textBaseline = "hanging";
//在画布上绘制填色的文本(输出的文本,开始绘制文本的X坐标位置,开始绘制文本的Y坐标位置)
cans.fillText(str, can.width / 8, can.height / 6);
cans.fillText("内部信息,禁止外传", can.width / 4, can.height / 2);
let div = document.createElement("div");
div.id = id;
div.style.pointerEvents = "none";
div.style.top = "30px";
div.style.left = "0px";
div.style.position = "fixed";
div.style.zIndex = "100000";
div.style.width = document.documentElement.clientWidth + "px";
div.style.height = document.documentElement.clientHeight + "px";
div.style.background = "url(" + can.toDataURL("image/png") + ") left top repeat";
document.body.appendChild(div);
return id;
};
// 该方法只允许调用一次
watermark.set = (str) => {
let id = setWatermark(str);
setInterval(() => {
if (document.getElementById(id) === null) {
id = setWatermark(str);
}
}, 500);
window.onresize = () => {
setWatermark(str);
};
};
export default watermark;