I want to clear the caches when my app updated in PlayStore in Android?

Question

我有一些数据存储在偏好中。如果在PlayStore中发现任何更新。我需要监听更新操作并且必须清除myapp的缓存。

Answer 1

To know if your app has been updated :

Store the current version code in shared preferences, and then use the below function in the main activity.

public static AppStart checkAppStart(Context context, SharedPreferences sharedPreferences) {
    PackageInfo pInfo;
    AppStart appStart = AppStart.NORMAL;
    try {
        pInfo = context.getPackageManager().getPackageInfo(
                context.getPackageName(), PackageManager.COMPONENT_ENABLED_STATE_DEFAULT);
        int lastVersionCode = sharedPreferences.getInt(
                Constants.LAST_APP_VERSION, -1);

        int currentVersionCode = pInfo.versionCode;
        appStart = checkAppStart(currentVersionCode, lastVersionCode);

        // Update version in preferences
        sharedPreferences.edit()
                .putInt(Constants.LAST_APP_VERSION, currentVersionCode).commit(); // must use commit here or app may not update prefs in time and app will loop into walkthrough
    } catch (PackageManager.NameNotFoundException e) {
        Log.w(LOG_TAG,
                "Unable to determine current app version from package manager. Defensively assuming normal app start.");
    }
    return appStart;
}

private static AppStart checkAppStart(int currentVersionCode, int lastVersionCode) {
    if (lastVersionCode == -1) {
        return AppStart.FIRST_TIME;
    } else if (lastVersionCode < currentVersionCode) {
        return AppStart.FIRST_TIME_VERSION;
    } else if (lastVersionCode > currentVersionCode) {
        Log.w(LOG_TAG, "Current version code (" + currentVersionCode
                + ") is less then the one recognized on last startup ("
                + lastVersionCode
                + "). Defensively assuming normal app start.");
        return AppStart.NORMAL;
    } else {
        return AppStart.NORMAL;
    }
}

AppStart is just an enum here:

public enum AppStart {
    FIRST_TIME,
    FIRST_TIME_VERSION,
    NORMAL
}

After that, to clear the cache : https://stackoverflow.com/a/23908638/1594776