<!-- index.ttml -->
<view class="card-area">
  <image mode="widthFix" src="{{filePath}}" style="width: 300px"></image>
  <button type="primary" bindtap="saveImageToPhotosAlbum">保存</button>
</view>

// index.js
Page({
  data: {
    filePath: "https://s3.pstatp.com/toutiao/static/img/logo.201f80d.png",
  },
  saveImageToPhotosAlbum() {
    tt.downloadFile({
      url: this.data.filePath,
      header: {
        "content-type": "application/json",
      },
      success: (res) => {
        let filePath = res.tempFilePath;
        tt.saveImageToPhotosAlbum({
          filePath, // 暂不支持网络图片/本地图片地址，需与tt.downloadFile一起使用
          success: (res) => {
            tt.showToast({ title: "成功保存到本地相册" });
          },
          fail: (err) => {
            let errType = err.errMsg.includes(
              "saveImageToPhotosAlbum:fail cancel"
            )
              ? "取消保存"
              : "保存失败";
            tt.showModal({
              title: errType,
              content: err.errMsg,
              showCancel: false,
            });
          },
        });
      },
      fail: (err) => {
        tt.showModal({
          title: "下载出错",
          content: err.errMsg,
          showCancel: false,
        });
      },
    });
  },
});