uniapp app 端打开pdf文件方式

uni.downloadFile({
              url: '文件地址',
              success: function (res) {
                var filePath = res.tempFilePath;
                uni.openDocument({
                  filePath: filePath,
                  showMenu: true,
                  success: function (res) {
                    console.log('打开文档成功');
                  }
                });
              }
            });