61 lines
2.0 KiB
JavaScript
61 lines
2.0 KiB
JavaScript
let watermark = {}
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const idd = '1.234523841642.1234124163';
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var _interval = null;
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let setWatermark = (str) => {
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let id = idd;
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if (document.getElementById(id) !== null) {
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document.body.removeChild(document.getElementById(id))
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}
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// 创建一个画布
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let can = document.createElement('canvas')
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// 设置画布的长宽
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can.width = 300
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can.height = 200
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let cans = can.getContext('2d')
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// 设置旋转角度
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cans.rotate(-20 * Math.PI / 180)
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cans.font = '12px'
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// 设置填充绘画的颜色、渐变或者模式
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cans.fillStyle = 'rgba(200, 200, 200, 0.20)'
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// 设置文本内容的当前对齐方式
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cans.textAlign = 'center'
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// 设置在绘制文本时使用的当前文本基线
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cans.textBaseline = 'Middle'
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// 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）
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cans.fillText(str, can.width / 3, can.height / 2)
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let div = document.createElement('div')
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div.id = id
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div.style.pointerEvents = 'none'
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div.style.top = '20px'
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div.style.left = '0px'
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div.style.position = 'fixed'
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div.style.zIndex = '100000'
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div.style.width = document.documentElement.clientWidth + 'px'
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div.style.height = document.documentElement.clientHeight + 'px'
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div.style.background = 'url(' + can.toDataURL('image/png') + ') left top repeat'
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document.body.appendChild(div)
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return id
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}
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// 该方法只允许调用一次
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// 添加水印的方法
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watermark.set = (str) => {
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let id = setWatermark(str);
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_interval = setInterval(() => {
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if (document.getElementById(id) === null) {
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id = setWatermark(str);
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}
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}, 500);
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window.onresize = () => {
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setWatermark(str);
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};
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}
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// 移除水印的方法
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watermark.remove = () => {
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if (document.getElementById(idd) !== null) {
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var box = document.getElementById(idd);
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box.parentNode.removeChild(box);
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_interval ? clearInterval(_interval) : '';
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}
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}
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export default watermark
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