微信小程序开发-长按图片保存

1、wxml中给需要保存的图片增加catchlongpress方法 

<image catchlongpress='saveToPhoto' src="{{customerImage}}" />

2、js文件中方法

 // 长按保存功能--授权部分
  saveToPhoto(e) {
    var that = this
    wx.showActionSheet({
      itemList: ['保存到相册'],
      success(res) {
        let url = that.data.customerImage;
        wx.getSetting({
          success: (res) => {
            if (!res.authSetting['scope.writePhotosAlbum']) {
              wx.authorize({
                scope: 'scope.writePhotosAlbum',
                success: () => {
                  // 同意授权
                  that.saveImgInner(url);
                },
                fail: (res) => {
                  console.log(res);
                  wx.showModal({
                    title: '保存失败',
                    content: '请开启访问手机相册权限',
                    success(res) {
                      wx.openSetting()
                    }
                  })
                }
              })
            } else {
              // 已经授权了
              that.saveImgInner(url);
            }
          },
          fail: (res) => {
            console.log(res);
          }
        })
      },
      fail(res) {
        console.log(res.errMsg)
      }
    })
  },
  // 长按保存功能--保存部分
  saveImgInner(url) {
    wx.getImageInfo({
      src: url,
      success: (res) => {
        let path = res.path;
        wx.saveImageToPhotosAlbum({
          filePath: path,
          success: (res) => {
            console.log(res);
            wx.showToast({
              title: '已保存到相册',
            })
          },
          fail: (res) => {
            console.log(res);
          }
        })
      },
      fail: (res) => {
        console.log(res);
      }
    })
  },