Android内部存储错误

Question

I am really new to android and writing a simple game for android.
In the game, like in most games you have score, now, I want the score to be saved in Internal Storage, and for some reason, I manage to save the score, but not load it back.
here is the code:

final TextView best = (TextView) findViewById(R.id.best);

public int read = -1;
public StringBuffer buffer = new StringBuffer();
public String scoreTxt = buffer.substring(0, buffer.indexOf(" ") + 1);
public int score = 0;
// Save
try {
    fileOutputStream = openFileOutput("record.txt", Context.MODE_PRIVATE);
    fileOutputStream.write(scoreString.getBytes());
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}finally {
    if (fileOutputStream != null) {
        try {
            fileOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
Toast.makeText(MainActivity.this, "Save() works fine", Toast.LENGTH_SHORT).show();

// load
try {
    FileInputStream fileInputStream = openFileInput("record.txt");
    while ((read = fileInputStream.read())!= -1){
        buffer.append((char)read);
    }
} catch (FileNotFoundException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
}
best.setText("Best: " + scoreTxt);
Toast.makeText(MainActivity.this, "load() is good too " +    scoreTxt, Toast.LENGTH_SHORT).show();

when I run the app, there is no crash or anything special in the logcat, but when ever I use scoreTxt the output is nothing, just " ".
can somebody help me solve this problem? Thanks

Answer 1

您永远不会在代码中为scoreTxt分配值。

Answer 2

You need to parse buffer after it has being populated.Now when scoreTxt is initialized buffer is null

You need to replace this

 best.setText("Best: " + scoreTxt);

with

scoreTxt = buffer.substring(0, buffer.indexOf(" ") + 1);
best.setText("Best: " + scoreTxt);

Answer 3

In addition I wouldn't store game score into a file because score changes frequently and you want to avoid disk access a lot. Store it in SharedPreferences and from time to time flush it to a file on a background thread.