Implementieren Spinner Inside Fragmnet

Question

Zunächst einmal, ich bin neu in Android-Programmierung, so dass es mir wirklich leid tut, wenn dies einige noob Fehler ist. Ich habe die gleiche Datei als eine Aktivität implementiert und es hat funktioniert. Aber wenn ich es in ein Fragment stecke, tut es das nicht. Ich konnte nicht ein anständiges Tutorial über Fragmente bekommen, also was ich implementiert habe kommt hauptsächlich aus Theorie und Beispielprojekten. Das Fehlerprotokoll sagt, "java.lang.NullPointerException: Versuch, virtuelle Methode" android.view.View android aufzurufen. view.View.findViewById (int) 'für eine Nullobjektreferenz'.

Ich überprüfte stackoverflow für das gleiche und fand die Antworten wo immer über falsche IDs. Aber in meinem Fall ist das ID korrekt, glaube ich. Es wäre schön, wenn mir jemand dabei helfen könnte. Oh und auch, wenn Sie könnten, bitte sagen Sie mir, ob ich den Code in den entsprechenden Funktionen geschrieben habe. Nur um zu verdeutlichen, ist die Funktion public void equalClicked (View v) der Berechnungsteil, der stattfinden soll, wenn die Schaltfläche angeklickt wurde. Ich arbeite jetzt seit fast 2 Tagen daran. -_-

Hier ist meine PhotosFragment.java Datei:

import android.content.Context; 
import android.net.Uri; 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.EditText; 
import android.widget.RadioButton; 
import android.widget.RadioGroup; 
import android.widget.Spinner; 
import android.widget.TextView; 

public class PhotosFragment extends Fragment { 
// TODO: Rename parameter arguments, choose names that match 
// the fragment initialization parameters 
EditText age,weight,height; 
TextView answer,answer2,answer3; 
String selected,a,b,c; 
RadioGroup gr; 
RadioButton r; 
double ans1,ans2,ans3; 

// TODO: Rename and change types of parameters 

private OnFragmentInteractionListener mListener; 

public PhotosFragment() { 
    // Required empty public constructor 
} 

// TODO: Rename and change types and number of parameters 
public static PhotosFragment newInstance() { 
    PhotosFragment fragment = new PhotosFragment(); 
    return fragment; 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    // Inflate the layout for this fragment 
    Spinner myspinner=(Spinner) getView().findViewById(R.id.fragment_photos_spinner); 
    ArrayAdapter<String> myAdapter =new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1,getResources().getStringArray(R.array.act)); 
    myAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); 
    myspinner.setAdapter(myAdapter); 
    age= (EditText) getView().findViewById (R.id.fragment_photos_age); 
    weight= (EditText) getView().findViewById (R.id.fragment_photos_weight); 
    height= (EditText) getView().findViewById (R.id.fragment_photos_height); 
    answer= (TextView) getView().findViewById (R.id.fragment_photos_answer); 
    answer2= (TextView) getView().findViewById (R.id.fragment_photos_answer2); 
    answer3= (TextView) getView().findViewById (R.id.fragment_photos_answer3); 
    gr=(RadioGroup) getView().findViewById(R.id.fragment_photos_rgroup); 
    myspinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener(){ 
     @Override 
     public void onItemSelected (AdapterView<?> parent,View view,int position,long id){ 
      selected=(String)parent.getItemAtPosition(position); 
     } 
     @Override 
     public void onNothingSelected (AdapterView<?> parent){ 

     } 
    }); 
    return inflater.inflate(R.layout.fragment_photos, container, false); 
} 

// TODO: Rename method, update argument and hook method into UI event 
public void onButtonPressed(Uri uri) { 
    if (mListener != null) { 
     mListener.onFragmentInteraction(uri); 
    } 
} 

@Override 
public void onAttach(Context context) { 
    super.onAttach(context); 
} 

@Override 
public void onDetach() { 
    super.onDetach(); 
    mListener = null; 
} 

public interface OnFragmentInteractionListener { 
    // TODO: Update argument type and name 
    void onFragmentInteraction(Uri uri); 
} 

public void equalClicked(View v){ 
    double input1= Double.parseDouble(age.getText().toString()); 
    double input2= Double.parseDouble(weight.getText().toString()); 
    double input3= Double.parseDouble(height.getText().toString()); 
    int rid=gr.getCheckedRadioButtonId(); 
    r=(RadioButton) getView().findViewById(rid); 
    String s=r.getText().toString(); 
    if(s.contentEquals("Male")) { 
     ans1=((10 * input2) + (6.25 * input3) - (5 * input1) + 5); 
    } 
    else 
    { 
     ans1=((10 * input2) + (6.25 * input3) - (5 * input1) - 161); 
    } 
    if(selected.contentEquals("Little to No exercise")){ 
     ans1=ans1 * 1.2; 
     ans2=ans1 + 1000; 
     ans3=ans1 - 1000; 
     a=Double.toString(ans1); 
     b=Double.toString(ans2); 
     c=Double.toString(ans3); 
     answer.setText(a + "cal"); 
     answer2.setText(b + "cal to increase 1 kg in a week"); 
     answer3.setText(c + "cal to decrease 1 kg in a week"); 

    } 
    else if(selected.contentEquals("Light exercise (1–3 days per week)")){ 
     ans1=ans1 * 1.375; 
     ans2=ans1 + 1000; 
     ans3=ans1 - 1000; 
     a=Double.toString(ans1); 
     b=Double.toString(ans2); 
     c=Double.toString(ans3); 
     answer.setText(a + "cal"); 
     answer2.setText(b + "cal to increase 1 kg in a week"); 
     answer3.setText(c + "cal to decrease 1 kg in a week"); 
    } 
    else if(selected.contentEquals("Moderate exercise (3–5 days per week)")){ 
     ans1=ans1 * 1.55; 
     ans2=ans1 + 1000; 
     ans3=ans1 - 1000; 
     a=Double.toString(ans1); 
     b=Double.toString(ans2); 
     c=Double.toString(ans3); 
     answer.setText(a + "cal"); 
     answer2.setText(b + "cal to increase 1 kg in a week"); 
     answer3.setText(c + "cal to decrease 1 kg in a week"); 
    } 
    else if(selected.contentEquals("Heavy exercise (6–7 days per week)")){ 
     ans1=ans1 * 1.725; 
     ans2=ans1 + 1000; 
     ans3=ans1 - 1000; 
     a=Double.toString(ans1); 
     b=Double.toString(ans2); 
     c=Double.toString(ans3); 
     answer.setText(a + "cal"); 
     answer2.setText(b + "cal to increase 1 kg in a week"); 
     answer3.setText(c + "cal to decrease 1 kg in a week"); 
    } 
    else{ 
     ans1=ans1 * 1.9; 
     ans2=ans1 + 1000; 
     ans3=ans1 - 1000; 
     a=Double.toString(ans1); 
     b=Double.toString(ans2); 
     c=Double.toString(ans3); 
     answer.setText(a + "cal"); 
     answer2.setText(b + "cal to increase 1 kg in a week"); 
     answer3.setText(c + "cal to decrease 1 kg in a week"); 
    } 

} 
} 

Hier ist es entsprechende XML-Datei:

<ImageView 
    android:layout_width="100dp" 
    android:layout_height="100dp" 
    android:layout_gravity="center" 
    android:alpha="0.3" 
    android:src="@drawable/ic_photo_library_black_24dp" /> 


<ScrollView 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
        xmlns:tools="http://schemas.android.com/tools" 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:paddingBottom="@dimen/activity_vertical_margin" 
        android:paddingLeft="@dimen/activity_horizontal_margin" 
        android:paddingRight="@dimen/activity_horizontal_margin" 
        android:paddingTop="@dimen/activity_vertical_margin" 
        android:orientation="vertical" 
        tools:context=".PhotosFragment"> 

     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@string/lbl_age" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 
     <EditText 
      android:id="@+id/fragment_photos_age" 
      android:inputType="number" 
      android:layout_width="178dp" 
      android:layout_height="wrap_content" /> 
     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@string/lbl_gender" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 
     <RadioGroup 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:id="@+id/fragment_photos_rgroup" 
      android:orientation="horizontal"> 
      <RadioButton 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:text="@string/lbl_female" 
       android:id="@+id/fragment_photos_female" 
       android:layout_gravity="center_horizontal" /> 

      <RadioButton 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:text="@string/lbl_male" 
       android:id="@+id/fragment_photos_male" /> 

     </RadioGroup> 

     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@string/lbl_weight" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 

     <EditText 
      android:id="@+id/fragment_photos_weight" 
      android:inputType="number" 
      android:layout_width="171dp" 
      android:layout_height="wrap_content" /> 

     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@string/lbl_height" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 

     <EditText 
      android:id="@+id/fragment_photos_height" 
      android:inputType="number" 
      android:layout_width="176dp" 
      android:layout_height="wrap_content" /> 
     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@string/lbl_daily_activity" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 

     <Spinner 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:id="@+id/fragment_photos_spinner" 
      android:layout_gravity="center_horizontal" /> 

     <Button 
      android:text="@string/btn_calculate" 
      android:onClick="equalClicked" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" /> 
     <TextView 
      android:id="@+id/fragment_photos_answer" 
      android:layout_width="400dp" 
      android:layout_height="wrap_content" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 
     <TextView 
      android:id="@+id/fragment_photos_answer2" 
      android:layout_width="300dp" 
      android:layout_height="wrap_content" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 
     <TextView 
      android:id="@+id/fragment_photos_answer3" 
      android:layout_width="300dp" 
      android:layout_height="wrap_content" 
      android:textAppearance="?android:attr/textAppearanceLarge"/> 

    </LinearLayout> 
</ScrollView> 

Hier ist ein Protokoll meiner Fehler:

Hier ist die Saiten .xml-Datei:

<!-- Calorie --> 
<string name="title_calorie">Calorie</string> 
<string name="lbl_age">Age</string> 
<string name="lbl_gender">Gender</string> 
<string name="lbl_female">Female</string> 
<string name="lbl_male">Male</string> 
<string name="lbl_weight">Weight (in kg)</string> 
<string name="lbl_height">Height (in cm)</string> 
<string name="lbl_daily_activity">Daily Activity</string> 
<string name="btn_calculate">Calculate</string> 
<string-array name="act"> 
    <item>Little to No exercise</item> 
    <item>Light exercise (1–3 days per week)</item> 
    <item>Moderate exercise (3–5 days per week)</item> 
    <item>Heavy exercise (6–7 days per week)</item> 
    <item>Very Heavy exercise (twice per day, extra heavy workouts)</item> 
</string-array> 

Answer 1

Sie müssen die View in Fragments aufblasen, bevor Sie nach IDs darauf suchen können. z.B.

@Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
    View v = inflater.inflate(R.layout.yourLayoutId, container, false); 
    Spinner myspinner=(Spinner) v.findViewById(R.id.fragment_photos_spinner); 

    return v; 
}