Question

我正在编写一个小游戏，我想在SD卡上保存分数和音量（启用或禁用）我的两个函数的代码是：

public static void load(FileIO files) {
    BufferedReader in = null;
    try {
        in = new BufferedReader(new InputStreamReader(
                files.readFile(".save")));
        soundEnabled = Boolean.parseBoolean(in.readLine());
        for (int i = 0; i < 5; i++) {
            highscores[i] = Integer.parseInt(in.readLine());
        }
    } catch (IOException e) {
        // :( It's ok we have defaults
    } catch (NumberFormatException e) {
        // :/ It's ok, defaults save our day
    } finally {
        try {
            if (in != null)
                in.close();
        } catch (IOException e) {
        }
    }
}

// -----------------------

public static void save(FileIO files) {
    BufferedWriter out = null;
    try {
        out = new BufferedWriter(new OutputStreamWriter(
                files.writeFile(".save")));
        out.write(Boolean.toString(soundEnabled));
        for (int i = 0; i < 5; i++) {
            out.write(Integer.toString(highscores[i]));
        }

    } catch (IOException e) {
    } finally {
        try {
            if (out != null)
                out.close();
        } catch (IOException e) {
        }
    }
}

程序运行时此代码没问题，但如果我重启设备，则分数会丢失。你知道为什么吗？

谢谢！

ps：FileIO类是：

  public class AndroidFileIO implements FileIO {
    Context context;
    AssetManager assets;
    String externalStoragePath;

    public AndroidFileIO(Context context) {
       this.context = context;
       this.assets = context.getAssets();
       this.externalStoragePath = Environment.getExternalStorageDirectory()
            .getAbsolutePath() + File.separator;
    }

    public InputStream readAsset(String fileName) throws IOException {
       return assets.open(fileName);
    }

    public InputStream readFile(String fileName) throws IOException {
       return new FileInputStream(externalStoragePath + fileName);
    }

    public OutputStream writeFile(String fileName) throws IOException {
       return new FileOutputStream(externalStoragePath + fileName);
    }

    public SharedPreferences getPreferences() {
       return PreferenceManager.getDefaultSharedPreferences(context);
    }
 }

Answer 1

这里有两个问题。首先，out.write不会在每次调用结束时插入换行符，您必须手动执行此操作。所以当你在cal中执行readline来解析你实际消耗文件中所有数据的布尔值时，会发生什么。其次，在离开该函数之前，需要刷新并关闭文件，以确保不在缓冲区中留下任何数据。

这是保存重写应该有效：

public static void save(FileIO files) {
BufferedWriter out = null;
try {
    out = new BufferedWriter(new OutputStreamWriter(
            files.writeFile(".mrnom")));
    out.write(Boolean.toString(soundEnabled));
    out.write("\n");
    for (int i = 0; i < 5; i++) {
        out.write(Integer.toString(highscores[i]));
        out.write("\n");

    }
    out.flush();
    out.close();
} catch (IOException e) {
} finally {
    try {
        if (out != null)
            out.close();
    } catch (IOException e) {

    }
}
}

Answer 2

我是第一次编程但是使用共享的prefs解决了这个问题。这样可以避免在更新应用程序时丢失数据。

在SD卡上保存数据

2 个答案: