Question

我正在尝试保存Switch的状态。我已经检查了stackoverflow上的其他答案，但仍然没有想出来。

我的主要活动是切换按钮（tgbutton）和开关（simpleSwitch1）。切换按钮的首选项有效但开关没有。不确定我是否正确保存了切换按钮的首选项，但对于大多数其他论坛/答案，他们已经这样做了。

请指教，

public class MainActivity extends AppCompatActivity {

Switch simpleSwitch1;
boolean switchState2 = false;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    // initiate view's
    simpleSwitch1 = (Switch) findViewById(R.id.simpleSwitch1);

    SharedPreferences sharedPrefs = getSharedPreferences("com.example.xyle", MODE_PRIVATE);
    simpleSwitch1.setChecked(sharedPrefs.getBoolean("NameOfThingToSave",false));

    switchState2 = sharedPrefs.getBoolean("NameOfThingToSave", false);

    final ToggleButton tgbutton;
    tgbutton = (ToggleButton) findViewById(R.id.toggle);

    SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    tgbutton.setChecked(sharedPreferences.getBoolean("toggleButton", false));  //default is false

    tgbutton.setOnClickListener(new ToggleButton.OnClickListener() {
        public void onClick(View v) {
            SharedPreferences sharedPreferences = PreferenceManager
                    .getDefaultSharedPreferences(getApplicationContext());
            SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putBoolean("toggleButton", tgbutton.isChecked());
            editor.commit();
        }
    });

    simpleSwitch1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked){
                SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
                editor.putBoolean("NameOfThingToSave", true);
                editor.commit();
                Toast.makeText(MainActivity.this, "This is on " + switchState2, Toast.LENGTH_SHORT).show();
            } else {
                SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
                editor.putBoolean("NameOfThingToSave", false);
                editor.commit();
                Toast.makeText(MainActivity.this, "This is off " + switchState2, Toast.LENGTH_SHORT).show();
            }
        }
    });

}

}

Answer 1

每次存储/检索不必要的值时，您都会声明新的SharedPreferences。只需使用一个SharedPreferences并使用不同的键跟踪不同的值。您应该将您的值存储在onStop()中，因为这更有意义。请尝试以下代码：

public class MainActivity extends AppCompatActivity {

Switch simpleSwitch1;
boolean switchState2 = false;
SharedPreferences sharedPrefs;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    // initiate view's
    simpleSwitch1 = (Switch) findViewById(R.id.simpleSwitch1);

    sharedPrefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

    if(sharedPrefs.contains("NameOfThingToSave")){
       simpleSwitch1.setChecked(sharedPrefs.getBoolean("NameOfThingToSave",false));
       switchState2 = sharedPrefs.getBoolean("NameOfThingToSave", false);
    }

    final ToggleButton tgbutton;
    tgbutton = (ToggleButton) findViewById(R.id.toggle);

    if(sharedPrefs.contains("toggleVutton")){
        tgbutton.setChecked(sharedPrefs.getBoolean("toggleButton", false));  //default is false
    }

    tgbutton.setOnClickListener(new ToggleButton.OnClickListener() {
        public void onClick(View v) {

        }
    });

    simpleSwitch1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

        }
    });

}

     @Override
     public void onStop() {
          // Store toggle state
          sharedPrefs.edit().putBoolean("toggleButton", tgbutton.isChecked()).commit();

         // Store switch state
         if (simpleSwitch1.isChecked){
                sharedPrefs.edit().putBoolean("NameOfThingToSave", true).commit();
                Toast.makeText(MainActivity.this, "This is on " + switchState2, Toast.LENGTH_SHORT).show();
            } else {
                sharedPrefs.edit().putBoolean("NameOfThingToSave", false).commit();
                Toast.makeText(MainActivity.this, "This is off " + switchState2, Toast.LENGTH_SHORT).show();
            }
       }
  }

希望这有帮助。

Answer 2

问题是，您使用different首选项（"com.example.xyle"和"com.example.xyz"）来存储并获得boolean值。
switchState2的值在您的代码中的任何位置都没有改变，这就是为什么在Toast消息中它始终显示相同的结果。

试试这个：

public class MainActivity extends AppCompatActivity {

Switch simpleSwitch1;
boolean switchState2 = false;

SharedPreferences sharedPrefs;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // initiate view's
    simpleSwitch1 = (Switch) findViewById(R.id.simpleSwitch1);

    sharedPrefs = getSharedPreferences("com.example.xyz", MODE_PRIVATE);
    simpleSwitch1.setChecked(sharedPrefs.getBoolean("NameOfThingToSave",false));

    switchState2 = sharedPrefs.getBoolean("NameOfThingToSave", false);

    final ToggleButton tgbutton = (ToggleButton) findViewById(R.id.toggle);
    tgbutton.setChecked(sharedPrefs.getBoolean("toggleButton", false));  //default is false

    tgbutton.setOnClickListener(new ToggleButton.OnClickListener() {
        public void onClick(View v) {
            SharedPreferences.Editor editor = sharedPrefs.edit();
            editor.putBoolean("toggleButton", tgbutton.isChecked());
            editor.commit();
        }
    });

    simpleSwitch1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked){
                SharedPreferences.Editor editor = sharedPrefs.edit();
                editor.putBoolean("NameOfThingToSave", true);
                editor.commit();

                switchState2 = true;
                Toast.makeText(MainActivity.this, "This is on " + switchState2, Toast.LENGTH_SHORT).show();
            } else {
                SharedPreferences.Editor editor = getSharedPreferences("com.example.xyz", MODE_PRIVATE).edit();
                editor.putBoolean("NameOfThingToSave", false);
                editor.commit();

                switchState2 = false;
                Toast.makeText(MainActivity.this, "This is off " + switchState2, Toast.LENGTH_SHORT).show();
            }
        }
    });

}

使用首选项保存切换状态，不保存布尔值

2 个答案: