如果应用程序重新打开共享preferences不节能布尔 [英] if application re-open SharedPreferences not saving boolean

问题描述

我在我的项目，称为以下code menu.class

  F1 =（按钮）findViewById（R.id.f1）;
f1.setOnClickListener（新View.OnClickListener（）{
    @覆盖
    公共无效的onClick（视图v）{
        // TODO自动生成方法存根
        意向意图=新的Intent（）;
        intent.setClassName（com.example.aplication，com.example.application.levelone）;
        startActivityForResult（意向，0）;
    }
}）;
}公共无效的onActivityResult（INT申请code，INT结果code，意图意图）{
    super.onActivityResult（要求code，结果code，意向）;    F2 =（按钮）findViewById（R.id.f2）;
    f2lock =（ImageView的）findViewById（R.id.f2lock）;    开关（结果code）{
        案例11：f2.setVisibility（View.VISIBLE）;
                 f2lock.setVisibility（View.GONE）;
    }
    共享preferences preferences = getShared preferences（preferences，MODE_PRIVATE）;
    布尔levelTwoUnlocked = preferences.getBoolean（F2，真正的）;    如果（levelTwoUnlocked）{
        f2.setVisibility（View.VISIBLE）;
        f2lock.setVisibility（View.GONE）;
    }
    其他{
        f2.setVisibility（View.GONE）;
        f2lock.setVisibility（View.VISIBLE）;
    }    f2.setOnClickListener（新View.OnClickListener（）{
        @覆盖
        公共无效的onClick（视图v）{
            意向意图=新的Intent（）;
            intent.setClassName（com.example.application，com.example.application.leveltwo）;
            startActivityForResult（意向，0）;
        }
    }）;
}
 

在code是工作的罚款。 F2 按钮设置可见和 f2lock 无形。
但是，当我重​​新打开应用程序的 F2 按钮回到可见。
难道我的preferences code不能完成？

更新时间：

我改变了preferences code这样的

 共享preferences preferences = getShared preferences（preferences，MODE_PRIVATE）;
    共享preferences.Editor ED = preferences.edit（）;
    布尔levelTwoUnlocked = preferences.getBoolean（F2，真正的）;
    ed.commit（）;
 

当我重新打开应用程序仍然有同样的问题。

解决方案

您检索 F2 的价值，但它并不像你保存任何地方。

  preferences.getBoolean（F2，真正的）;
 

这将返回 F2 或真正如果 f2的最后一次保存的值不存在（即你从来没有在你的共享preference实例保存它） - 它不会创建或保存在共享preferences实例的值你。

要保存的价值，你需要创建一个共享preferences编辑器，设置的值（或值）要保存并提交：

 共享preferences.Editor编辑器= preferences.edit（）;
editor.putBoolean（F2，levelTwoUnlocked）;
editor.commit（）;
 

现在您下次阅读 F2 值时，就会产生什么价值，你上次提交。

I have the following code in my project called menu.class

f1 =(Button)findViewById(R.id.f1);      
f1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v){
        // TODO Auto-generated method stub
        Intent intent = new Intent ();
        intent.setClassName ("com.example.aplication", "com.example.application.levelone");
        startActivityForResult (intent, 0);              
    }             
}); 
}

public void onActivityResult (int requestCode, int resultCode, Intent intent) {
    super.onActivityResult (requestCode, resultCode, intent);

    f2=(Button)findViewById(R.id.f2);      
    f2lock=(ImageView)findViewById(R.id.f2lock);

    switch (resultCode) {
        case 11: f2.setVisibility(View.VISIBLE);
                 f2lock.setVisibility(View.GONE);               
    }                                  
    SharedPreferences preferences = getSharedPreferences("preferences", MODE_PRIVATE);
    boolean levelTwoUnlocked = preferences.getBoolean("f2", true);

    if(levelTwoUnlocked){
        f2.setVisibility(View.VISIBLE);
        f2lock.setVisibility(View.GONE);
    }
    else {
        f2.setVisibility(View.GONE);
        f2lock.setVisibility(View.VISIBLE);
    } 

    f2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v){
            Intent intent = new Intent ();
            intent.setClassName ("com.example.application", "com.example.application.leveltwo");
            startActivityForResult (intent, 0);              
        }             
    });     
}

The code is working fine. f2 button is set visible and f2lock invisible. But when I re-open the application the f2 button back to visible. Did my Preferences code not complete?

UPDATED

i had changed the preferences code like this

    SharedPreferences preferences = getSharedPreferences("preferences", MODE_PRIVATE);
    SharedPreferences.Editor ed = preferences.edit();
    boolean levelTwoUnlocked = preferences.getBoolean("f2", true);
    ed.commit();                

and when i re-open the application it still had the same problems

解决方案

You are retrieving the value of f2, but it doesn't look like you're saving it anywhere.

preferences.getBoolean("f2", true);

This will return the last saved value of f2 or true if f2 doesn't exist (i.e. you've never saved it in your SharedPreference instance) - it won't create or save any value in the SharedPreferences instance for you.

To save the value, you need to create a SharedPreferences editor, set the value (or values) you want to save and commit it:

SharedPreferences.Editor editor = preferences.edit();
editor.putBoolean("f2", levelTwoUnlocked);
editor.commit();

Now the next time you read the f2 value, it will have whatever value you last committed.

这篇关于如果应用程序重新打开共享preferences不节能布尔的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！