downloadFile(url) {

      uni.downloadFile({

        url,

        fail: function(res) {

          uni.showModal({

            title: '提示',

            content: '保存失败',

          })

        },

        success: function(res) {

let file = res.tempFilePath;

uni.saveImageToPhotosAlbum({

filePath: file,

success: () => {

uni.hideLoading();

uni.showToast({

title:"图片已保存"

});

},

fail: () => {

uni.hideLoading();

uni.showToast({

title:"图片保存失败"

});

}

});

        },

      });

    },

照此修改即可