將返回的流數據轉換爲url

// 將返回的流數據轉換爲url
getObjectURL(file) {
      let url = null;
      if (window.createObjectURL != undefined) { // basic
          url = window.createObjectURL(file);
      } else if (window.webkitURL != undefined) { // webkit or chrome
          try {
            url = window.webkitURL.createObjectURL(file);            
          } catch (error) {
            
          }
      } else if (window.URL != undefined) { // mozilla(firefox)
        try {
          url = window.URL.createObjectURL(file);
        } catch (error) {
          
        }
      }
      return url;
    }