HarmonyOS 使用防截图API报错

示例参考：

onPageShow(): void {
  // noScreen()
  try {
    let isPrivacyMode: boolean = true;
    //let windowClass: window.Window = window.findWindow("test");
    let windowClass: window.Window | undefined = undefined;
    try {
      window.getLastWindow(getContext(), (err: BusinessError, data) => {
        const errCode: number = err.code;
        if (errCode) {
          console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(err));
          return;
        }
        windowClass = data;
        let promise = windowClass.setWindowPrivacyMode(isPrivacyMode); // 设置防截屏录屏
        promise.then(() => {
          console.info('Succeeded in setting the window to privacy mode.');
        }).catch((err: BusinessError) => {
          console.error(`ErrorCode: ${err.code}, Message: ${err.message}`);
        })
        console.info('Succeeded in obtaining the top window. Data: ' + JSON.stringify(data));
      });
    } catch (exception) {
      console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(exception));
    }
  } catch (e) {
    console.log(JSON.stringify(e))
  }
}

需要注意windowClass.setWindowPrivacyMode(isPrivacyMode)方法需要添加权限：

{
  "name" : "ohos.permission.PRIVACY_WINDOW"
}