Question

嘿，伙计们如何在我的项目中使用共享偏好。我在主动和第二次活动中有一个浮动按钮，当我点击浮动按钮时，指南针将被禁用，然后当我进入第二个活动时，指南针被启用而被禁用。如何解决这个问题？

这是我的代码基本活动

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);



    FloatingActionButton compass1 = (FloatingActionButton)findViewById(R.id.comp);
    compass1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if(findViewById(R.id.relativeLayout1).getVisibility()==View.VISIBLE){
                findViewById(R.id.relativeLayout1).setVisibility(View.GONE);
                Toast.makeText(getApplicationContext(),"Compass Has Been Disabled",Toast.LENGTH_SHORT).show();
            }

            else{

                findViewById(R.id.relativeLayout1).setVisibility(View.VISIBLE);
                Toast.makeText(getApplicationContext(),"Compass Has Been Enabled",Toast.LENGTH_SHORT).show();
            }
        }

    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);



}

@覆盖 public boolean onNavigationItemSelected（MenuItem item）{

    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_first) {
        Intent myIntent = new Intent(this,MainActivity.class);
        myIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(myIntent);
        finish();
    } else if (id == R.id.nav_second) {
        Intent myIntent = new Intent(this,SecondFloor.class);
        myIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(myIntent);
        finish();



    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

Answer 1

你不需要SharedPreferences。只需传递具有指南针可见性状态的Intent extra。

从类别字段isCompassVisible

中的compass1单击侦听器中保存状态

为SecondFloor创建意图时：

Intent myIntent = new Intent(this,SecondFloor.class);
myIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
myIntent.putExtra("isCompassVisible", isCompassVisible);
startActivity(myIntent);

在SecondFloor活动onCreate（或您需要的任何地方）：

if(getIntent().hasExtra("isComapssVisible")
    comapssView.setVisibility(getIntent().getBooleanExtra("isCompassVisible", true) ? View.VISIBLE : View.GONE);

Answer 2

1.您可以使用“共享”偏好设置将值设置为：

SharedPreferences sharedPreferences = getSharedPreferences(Values.SHARED_PREF_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("isShowing", true/false);
editor.apply();

并将其作为：

SharedPreferences prefs = ((Activity)context).getSharedPreferences("TAG", Context.MODE_PRIVATE);
Boolean shown = prefs.getBoolean("isShowing",true);

但你最好在意图中传递布尔值。

只需将其传递给：

Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
Bundle bundle = new Bundle();
bundle.putBoolean("isShowing",true/false);
intent.putExtras(bundle);
startActivity(intent);

得到它：

Boolean b = getIntent().getBooleanExtra("isShowing",false);

或者，您也可以在活动或utils文件夹中使用公共静态布尔变量，您可以从任一活动访问该文件夹。

如何在活动之间传递View可见性状态

2 个答案: