編輯SharedPreferences

Question

我很新到Java/Android開發，我想簡單地擁有用戶檢查「男孩」或「女孩」單選按鈕，並將它寫入SharedPreferences如此我可以在其他活動中使用它。每當我嘗試打開這個活動，但我的應用程序只是崩潰。

public class NewBabyProfile extends Activity { 

String GENDER = "Baby1Gender"; 

// SharedPreferences initializations 
SharedPreferences babyOneGender = getSharedPreferences(getString(R.string.baby_one_profile), Context.MODE_PRIVATE); 
SharedPreferences.Editor editor = babyOneGender.edit(); 

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

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.new_baby_profile, menu); 
    return true; 
} 

public void onRadioButtonClicked(View genderSelection){ 
    boolean checked = ((RadioButton) genderSelection).isChecked(); 

    switch(genderSelection.getId()) { 
     case R.id.gender_boy: 
      if (checked) 
       editor.putString("gender","boy").commit(); 
      break; 

     case R.id.gender_girl: 
      if (checked) 
       editor.putString("gender","girl").commit(); 
      break; 

    } 
} 

} 

Answer 1

不能直接初始化類中的以下兩種。

SharedPreferences babyOneGender = getSharedPreferences(getString(R.string.baby_one_profile), Context.MODE_PRIVATE); 
SharedPreferences.Editor editor = babyOneGender.edit(); 

你的SharedPreferences初始化應該像的onCreate方法內發生的（）或的onResume（） 遷入的onCreate（捆綁）和你的應用程序，這將不會再崩潰。另外，請檢查您的logcat，找出自己的問題:)

最終代碼： -

public class NewBabyProfile extends Activity { 

String GENDER = "Baby1Gender"; 

//Global declaration. 
SharedPreferences babyOneGender; 
SharedPreferences.Editor editor; 


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

    //Initializations inside onCreate() so no error. 

    babyOneGender = getSharedPreferences(getString(R.string.baby_one_profile), Context.MODE_PRIVATE); 
    editor = babyOneGender.edit(); 


} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.new_baby_profile, menu); 
    return true; 
} 

public void onRadioButtonClicked(View genderSelection){ 
    boolean checked = ((RadioButton) genderSelection).isChecked(); 

    switch(genderSelection.getId()) { 
     case R.id.gender_boy: 
      if (checked) 
       editor.putString("gender","boy").commit(); 
      break; 

     case R.id.gender_girl: 
      if (checked) 
       editor.putString("gender","girl").commit(); 
      break; 

    } 
} 

} 

Answer 2

試試這個

SharedPreferences babyOneGender = getApplication().getSharedPreferences(getString(R.string.baby_one_profile), Context.MODE_PRIVATE); 

Answer 3

babyOneGender &編輯的舉動初始化的onCreate：

SharedPreferences babyOneGender; 
    SharedPreferences.Editor editor; 

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

     babyOneGender = getSharedPreferences(getString(R.string.baby_one_profile), Context.MODE_PRIVATE); 
     editor = babyOneGender.edit();