57 lines
1.6 KiB
JavaScript
57 lines
1.6 KiB
JavaScript
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 = 120;
|
||
can.height = 120;
|
||
|
||
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, 0.40)';
|
||
//设置文本内容的当前对齐方式
|
||
cans.textAlign = 'left';
|
||
//设置在绘制文本时使用的当前文本基线
|
||
cans.textBaseline = 'Middle';
|
||
//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 / 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;
|