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所属分类:Web前端
声明:仅为方便自己所需,也希望能方便他人,如有侵权,联系删除。
1,DataUrl转为File
1 /** 2 * DataUrl转为File 3 * @param {String} dataUrl - dataUrl地址 4 * @param {String} fileName - file文件名 5 */ 6 dataURLtoFile(dataUrl, fileName){ 7 var arr = dataUrl.split(','), mime = arr[0].match(/:(.*?);/)[1], 8 bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n); 9 while(n--){ 10 u8arr[n] = bstr.charCodeAt(n); 11 } 12 return new File([u8arr], fileName, {type:mime}); 13 }
2,url转base64
/** * url转base64 * @param {String} url - url地址 */ urlToBase64(url) { return new Promise ((resolve,reject) => { let image = new Image(); image.onload = function() { let canvas = document.createElement('canvas'); canvas.width = this.naturalWidth; canvas.height = this.naturalHeight; // 将图片插入画布并开始绘制 canvas.getContext('2d').drawImage(image, 0, 0); // result let result = canvas.toDataURL('image/png') resolve(result); }; // CORS 策略,会存在跨域问题https://stackoverflow.com/questions/20424279/canvas-todataurl-securityerror image.setAttribute("crossOrigin",'Anonymous'); image.src = url; // 图片加载失败的错误处理 image.onerror = () => { reject(new Error('转换失败')); }; }); } //使用例子 this.urlToBase64(this.Url).then(res=>{ console.log(res); })
3,生成Uuid
function CreateUuid() { let Time = new Date().getTime(); let uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx' .replace(/[xy]/g, function(res) { let Random = (Time + Math.random() * 16) % 16 | 0; Time = Math.floor(Time / 16); return (res == 'x' ? Random : (Random & 0x3 | 0x8)).toString(16); }); return "pdd"+ uuid; };
4,获取url路径后的参数
// 不传name返回所有值,否则返回对应值 function getUrlParams(name) { var url = window.location.search; if (url.indexOf('?') == 1) { return false; } url = url.substr(1); url = url.split('&'); var name = name || ''; var nameres; // 获取全部参数及其值 for(var i=0;i<url.length;i++) { var info = url[i].split('='); var obj = {}; obj[info[0]] = decodeURI(info[1]); url[i] = obj; } // 如果传入一个参数名称,就匹配其值 if (name) { for(var i=0;i<url.length;i++) { for (const key in url[i]) { if (key == name) { nameres = url[i][key]; } } } } else { nameres = url; } // 返回结果 return nameres; }
5,Canvas生成水印
/** * Canvas生成水印 * @param {dom} element - dom元素 * @param {String} text - 水印文本 */ function watermark(element, text) { var canvas = '' , ctx = '' , data = '' , fontWidth = '12.5' , node = document.querySelector(element) , width = node.clientWidth , height = node.clientHeight; canvas = document.createElement("canvas"); canvas.width = "100"; canvas.height = "100"; ctx = canvas.getContext("2d"); ctx.clearRect(0, 0, 200, 200); fontWidth = document.documentElement.clientWidth * 3 * 12.5 / 4000; ctx.font = fontWidth + "px 黑体"; ctx.rotate(-20 * Math.PI / 180); ctx.fillStyle = "rgba(0,0,0, .2)"; ctx.fillText(text, -20, 80); data = canvas.toDataURL("image/png", 1); node.style.background = 'url(' + data + ') repeat'; }; watermark("#canvas","相约1998");
6,请求本地Json
let Params = 'data/data.json'; var PddAjax2 = new Promise(PddAjax); // 成功 PddAjax2.then(function(res){ console.log(res) }) function PddAjax(resolve , reject){ this.Params = Params; $.ajax({ type:'get', url:Params, success: function(res) { resolve(res); }, error: function(res) { reject(res); } }) }