SharedPreferences不增加整数值-Android

Question

I am wanting to store an int in SharedPreferences . The int represents which level the user is on in my game. Before the game starts, this code is executed:

    int level;

    // Restore preferences
    SharedPreferences settings = getSharedPreferences("level_SP", 0);
    level = settings.getInt("currentLevel", 0);
    if(level == 0) {
        level++;
    }
    String str = Integer.toString(level);
    title.setText(str); 

The text that is outputted from title.setText(str); is 1 .

For testing purposes, no matter how the user does in the game he passes the level. After the game is over, this code is executed.

public void levels() {

    // do calculations here to see if user passed level.


    // Restore preferences
    SharedPreferences settings = getSharedPreferences("level_SP", 0);
    int level = settings.getInt("currentLevel", 0);
    int newLevel = level++;

    // We need an Editor object to make preference changes.
    SharedPreferences.Editor editor = settings.edit();
    editor.putInt("currentLevel", newLevel);

    // Commit the edits!
    editor.commit();
}

Then when the user starts the game again, they should be at level 2. In the code pasted at the top of this post, this line of code: title.setText(str); should output 2 , but it still is saying 1 . That tells me that the int I stored in SharedPreferences is not incrementing.

My question is, am I "getting" the SharedPreferences correctly? If yes, am I "editting" the SharedPreferences correctly? If not on either one, what am I doing wrong?

EDIT

Thought: Do the 0 that are scattered throughout my above code mean anything? Should they be something else?

Answer 1

Use

editor.putInt("currentLevel", newLevel);

instead.

When you get the new level you're writing it to a different preference than when you read.

Answer 2

It looks like you want to change this

editor.putInt("newLevel", newLevel);

to

editor.putInt("currentLevel", newLevel);

You are creating a new SharedPreference instead of editing the exisiting so the currentLevel never changes from 1

Answer 3

This line is the problem:

int newLevel = level++;

you are using the post-increment operator, which means that this is the same as:

int newLevel = level;
level = level + 1;

try

int newLevel = level + 1;