HarmonyOS 某页面上某按钮通过api将应用切后台再次唤醒后保持原页面

可以考虑使用最小化窗口而不是关闭应用，示例：

let windowClass: window.Window | undefined = undefined;
try {
  window.getLastWindow(getContext(this), (err: BusinessError, data) => {
    const errCode: number = err.code;
    if (errCode) {
      console.error(`Failed to obtain the top window. Cause code: ${err.code}, message: ${err.message}`);
      return;
    }
    windowClass = data;
    console.info('Succeeded in obtaining the top window. Data: ' + JSON.stringify(data));
    windowClass?.minimize((err: BusinessError) => {
      const errCode: number = err.code;
      if (errCode) {
        console.error(`Failed to minimize the window. Cause code: ${err.code}, message: ${err.message}`);
        return;
      }
      console.info('Succeeded in minimizing the window.');
    });
  });
} catch (exception) {
  console.error(`Failed to obtain the top window. Cause code: ${exception.code}, message: ${exception.message}`);
}