base64上传七云获取key

上传到七云牛 base64 转化为 key(原生的ajax)

putb64 = async () => {
  /*picUrl用来存储返回来的url*/
  let picBase = base64图片;
  /*把头部的data:image/png;base64,去掉。（注意：base64后面的逗号也去掉）*/
  picBase = picBase.substring(23);

  /*通过base64编码字符流计算文件流大小函数*/
  function fileSize(str) {
    let fileSize,
      indexOf = str.indexOf("=");
    if (indexOf > 0) {
      str = str.substring(0, indexOf); //把末尾的’=‘号去掉
    }
    fileSize = parseInt(str.length - (str.length / 8) * 2);
    return fileSize;
  }

  //https://upload-z2.qiniu.com/putb64/ 只适用于七牛云华南空间
  const url = `https://upload-z2.qiniup.com/putb64/${fileSize(picBase)}`;
  const xhr = new XMLHttpRequest();
  xhr.onreadystatechange = function () {
    if (xhr.readyState === 4 && xhr.status === 200) {
      let keyText = xhr.responseText;
      console.log(keyText);
    }
  };
  xhr.open("POST", url, true);
  xhr.setRequestHeader("Content-Type", "application/octet-stream");
  xhr.setRequestHeader("Authorization", `UpToken ${this.state.uptoken}`);
  xhr.send(picBase);
};