Function startTracking

frontend/src/App.tsx:807–872

()

  }

  async function startTracking() {
    if (!navigator.geolocation) {
      setMessage("当前浏览器不支持定位，请换用手机系统浏览器测试。");
      setPermissionHint("");
      return;
    }
    setTracking(true);
    setPermissionHint("");
    setMessage("正在请求定位权限...");
    checkLocationPermission().then((hint) => {
      if (hint) setPermissionHint(hint);
    });
    try {
      if ("wakeLock" in navigator) {
        (navigator as any).wakeLock?.request?.("screen").catch(() => null);
      }
    } catch {
      // Wake lock is optional.
    }
    watchRef.current = navigator.geolocation.watchPosition(
      async (position) => {
        const { latitude, longitude, accuracy, speed } = position.coords;
        const result = await api.submitPosition(challengeId, {
          lat: latitude,
          lng: longitude,
          accuracy_m: accuracy,
          speed_mps: speed ?? undefined,
        });
        if (result.map_lat != null && result.map_lng != null) {
          setGpsPosition({
            lat: result.map_lat,
            lng: result.map_lng,
            mode: "gps",
            label: "GPS 当前位置",
          });
        }
        if (result.cell_id) {
          setGpsCellId(result.cell_id);
        }
        if (result.accepted && result.cell_id) {
          setUnlocked((prev) => new Set(prev).add(result.cell_id!));
          setMine((prev) => new Set(prev).add(result.cell_id!));
          if (result.stats) setChallenge((prev) => (prev ? { ...prev, stats: result.stats! } : prev));
          setPermissionHint("");
          setMessage(`定位正常，精度 ${Math.round(accuracy)} 米。`);
        } else {
          const reasonText =
            result.reason === "low_accuracy"
              ? "信号弱，暂不计入"
              : result.reason === "too_fast"
                ? "移动太快，暂不计入"
                : result.reason === "outside_area"
                  ? "你还不在挑战范围内"
                  : "当前位置暂不计入";
          setMessage(reasonText);
        }
      },
      (err) => {