常用方法

vue element中input限制只能输入正整数

@input="(val)=>{textVal = val.replace(/[^\d]/g, '')}" 

vue input 只允许输入整数、整数和小数（保留小数点后两位）

<el-input size="small" onkeyup="this.value=this.value.match(/\d+\.?\d{0,2}/)" onafterpaste="this.value=this.value.match(/\d+\.?\d{0,2}/)"
             v-model="scope.row.agentPrice" maxlength="9"></el-input>

<!--input只允许输入整数-->
<el-input size="small" onkeyup="this.value=this.value.replace(/\D/g,'')" onafterpaste="this.value=this.value.replace(/\D/g,'')"
             v-model.number="scope.row.quantityNum" maxlength="9"></el-input>

在vue中下载图片 ——文章适用于下载字符流图片

<div  class="link-wrapper" @click="download">下载</div>
download() {
      this.getUrlBase64(‘此处传入图片链接’).then(base64 => {
        let link = document.createElement('a')
        link.href = base64
        link.download = 'qrCode.png'
        link.click()
      })
    },

getUrlBase64(url) {
      return new Promise(resolve => {
        let canvas = document.createElement('canvas')
        let ctx = canvas.getContext('2d')
        let img = new Image()
        img.crossOrigin = 'Anonymous' //允许跨域
        img.src = url
        img.onload = function() {
          canvas.height = 300
          canvas.width = 300
          ctx.drawImage(img, 0, 0, 300, 300)
          let dataURL = canvas.toDataURL('image/png')
          canvas = null
          resolve(dataURL)
        }
      })
    },