我想使用保存的首選項獲取選定的單選按鈕，但活動未打開？

Question

這是代碼

public RadioButton selectedSex;
public int selectedRadioButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);
    setContentView(R.layout.activity_personal_data);

    progressDialog = new ProgressDialog(this);

    // 0=FULL_NAME
    // 1 =BIRTHDAY
    //2=ADDRESS_LINE
    // 3=CITY
    //4=STATE
    // 5=PINCODE
    // 6=PHONE
    mUserPersonalInfo[0] = findViewById(R.id.user_name);
    mUserPersonalInfo[1]=findViewById(R.id.user_birth_date);
    mUserPersonalInfo[2]=findViewById(R.id.user_address_line);
    mUserPersonalInfo[3]=findViewById(R.id.user_city);
    mUserPersonalInfo[4]=findViewById(R.id.user_state);
    mUserPersonalInfo[5] = findViewById(R.id.userPhoneNumber);
    mUserPersonalInfo[6] = findViewById(R.id.user_pincode);
    mAuth = FirebaseAuth.getInstance();
    mSex=findViewById(R.id.user_sex);
    mNext = findViewById(R.id.personal_details_next_button);
    sharedpreferences = getSharedPreferences("personalPref", Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedpreferences.edit();

    selectedRadioButton  = mSex.getCheckedRadioButtonId();
    selectedSex  = findViewById(selectedRadioButton);

    mUserPersonalInfo[1].setText( sharedpreferences.getString("userDOB", null));
    mUserPersonalInfo[0].setText(sharedpreferences.getString("userName", null));
    mUserPersonalInfo[2].setText(sharedpreferences.getString("userAddressline", null));
    mUserPersonalInfo[3].setText(sharedpreferences.getString("userCity", null));
    mUserPersonalInfo[4].setText( sharedpreferences.getString("userState", null));
    mUserPersonalInfo[5].setText( sharedpreferences.getString("userPhone", null));
    mUserPersonalInfo[6].setText(sharedpreferences.getString("userPincode", null));
    selectedSex.setSelected( sharedpreferences.getBoolean("userSex", false));
  //  mNext.setProgress(0);

   // FirebaseDatabase.getInstance().setPersistenceEnabled(true);
    mNext.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        //    mNext.setProgress(1);

            final String Birthday = mUserPersonalInfo[1].getText().toString();
            UserName = mUserPersonalInfo[0].getText().toString();
            final String Addressline = mUserPersonalInfo[2].getText().toString();
            final String City = mUserPersonalInfo[3].getText().toString();
            final String State = mUserPersonalInfo[4].getText().toString();
           PhoneNumber = mUserPersonalInfo[5].getText().toString();
            final String Pincode = mUserPersonalInfo[6].getText().toString();


   editor.putString("userName", UserName);
            editor.putString("userPhone", PhoneNumber);
            editor.putString("userDOB", Birthday);
            editor.putBoolean("userSex", selectedSex.isChecked());
            editor.putString("userAddressline", Addressline);
            editor.putString("userCity", City);
            editor.putString("userPincode", Pincode);
            editor.putString("userState", State);

            editor.apply();

進程：com.teepe.teepe，PID：18864 java.lang.RuntimeException：無法啟動活動 ComponentInfo{com.teepe.teepe/com.teepe.teepe.KYC.personalData}：java.lang.NullPointerException：嘗試調用虛擬在 android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 處 android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) 處的空對象引用上的方法“void android.widget.RadioButton.setSelected(boolean)” android.app.ActivityThread.-wrap12(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os。 Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6077) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$ MethodAndArgsCaller.run(ZygoteInit.java:866) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) 由：java.lang.NullPointerException: Attempt to i 在 com.teepe.teepe.KYC.personalData.onCreate(personalData.java:92) at android.app.Activity.performCreate(Activity) 處的空對象引用上調用虛擬方法“void android.widget.RadioButton.setSelected(boolean)” .java:6662)

Answer 1

似乎mSex.getCheckedRadioButtonId()沒有返回正確的 Id。

因此findViewById(selectedRadioButton)無法找到視圖。 因此，在setSelected方法調用中出現 NullPointerException。

Answer 2

在這找不到視圖

RadioButton selectedSex = findViewById(selectedRadioButton);

必須像：

RadioButton selectedSex = findViewById(R.id.selectedRadioButton);