base64img() {
      uni.chooseImage({
        count: 6, //默认9
        sizeType: ["original", "compressed"], //可以指定是原图还是压缩图，默认二者都有
        sourceType: ["album"], //从相册选择
        success: function (res) {
          console.log(res.tempFilePaths);
          //#ifdef APP-PLUS
          plus.io.resolveLocalFileSystemURL(
            res.tempFilePaths[0],
            function (entry) {
              entry.file(function (file) {
                var fileReader = new plus.io.FileReader();
                fileReader.readAsDataURL(file);
                fileReader.onloadend = function (evt) {
                  console.log(evt);
                };
              });
            }
          );
          //#endif
        },
      });
    },