wx.downloadFile({
      url: 'https://www.ikaiyin.com/email/cm/Journalism Critical Issues by Stuart Allan (z-lib.org).pdf',
            //url: 'https://www.ikaiyin.com/email/cm/'+e.target.dataset.dir_name,
      success: function (res) {
        console.log(res);
        const filePath = res.tempFilePath
        wx.openDocument({
          filePath: filePath, 
         fileType: 'pdf',
          success: function (res) {
            console.log('打开文档成功')
          },
          fail(res){
            console.log(res);
          }
        })
      }
    })
第二行注释就无法访问了返回404