微信小程序 下载图片保存到相册

wxml

js

监听图片下载进度

downImg:function(e){
         var _this = this
         // 获取图片地址
         var img = e.currentTarget.dataset.src 
         console.log(img)
         // 下载监听进度
         const downloadTask = wx.downloadFile({
           url: img,
           success:function(res){
               console.log(res)
               if(res.statusCode === 200){
                  wx.saveImageToPhotosAlbum({
                      filePath:res.tempFilePath,
                      success:function(res){
                          wx.showToast({
                            title: '保存图片成功',
                          })
                      },
                      fail:function(res){
                        wx.showToast({
                          title: '保存图片失败',
                        })
                      }
                  })
               }
           }
         })
         downloadTask.onProgressUpdate((res)=>{
          console.log('下载进度', res.progress)
          console.log('已经下载的数据长度', res.totalBytesWritten)
          console.log('预期需要下载的数据总长度', res.totalBytesExpectedToWrite)
            if(res.progress === 100){
               this.setData({
                  progress:''
               })
            }else{
               this.setData({
                  progress:res.progress + '%'
               })
            }
         })
      },

参考：https://zhuanlan.zhihu.com/p/237325032

https://zhuanlan.zhihu.com/p/41710340