SpinnerにJSON ArrayListを設定する

どのようにオブジェクトをprojectListのArrayListからSpinnerに配置するのですか？私はそれだけでクラッシュした私のコードを実行するとここに私のコードSpinnerにJSON ArrayListを設定する

public class MainPage extends AppCompatActivity implements AsyncResponse { 
private ArrayList<ProjectNames> projectsList; 
private Spinner spinner1; 
final String LOG = "MainPage"; 


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

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
        .setAction("Action", null).show(); 
     } 
    }); 
    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 


    PostResponseAsyncTask taskRead = new PostResponseAsyncTask(MainPage.this, this); 
    taskRead.execute("http://10.0.2.2/Client/ProjectRead.php"); 


} 

@Override 
public void processFinish(String s) { 
    projectsList = new JsonConverter<ProjectNames>().toArrayList(s, ProjectNames.class); 
    //Log.d(LOG, "processFinish: " + s); 
    BindDictionary<ProjectNames> dict = new BindDictionary<ProjectNames>(); 

    dict.addStringField(R.id.tvProjectName, new StringExtractor<ProjectNames>() { 

     @Override 
     public String getStringValue(ProjectNames projects, int position) { 
      return projects.projectname; 
     } 
    }); 

    FunDapter<ProjectNames> adaptor = new FunDapter<>(MainPage.this, projectsList, R.layout.support_simple_spinner_dropdown_item, dict); 
    spinner1 = (Spinner) findViewById(R.id.spFirstChoice); 
    spinner1.setAdapter(adaptor); 
}

} `

です。注：ProjectNameクラスのオブジェクトを格納するために使用するtvProjectNamesを作成したカスタムXMLファイルを作成しました。 ProjectName.class：

package com.example.anthony.project2016; 

import com.google.gson.annotations.SerializedName; 

public class ProjectNames { 

@SerializedName("id") 
public int id; 
@SerializedName("projectname") 
public String projectname; 
}

私はprocessFinishで取得することです：

processFinish: [{"id":"1","projectname":"project1"},{"id":"2","projectname":"project2"},{"id":"3","projectname":"project3"},{"id":"4","projectname":"project4"},{"id":"5","projectname":""},{"id":"6","projectname":"Project5"}]`

これは、アプリがクラッシュした後にエラーです：

04-01 22:55:31.478 2350-2350/com.example.anthony.project2016 E/AndroidRuntime: FATAL EXCEPTION: main 
                      Process: com.example.anthony.project2016, PID: 2350 
                      java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setVisibility(int)' on a null object reference 
                       at com.amigold.fundapter.FunDapterUtils.handleStringFields(FunDapterUtils.java:231) 
                       at com.amigold.fundapter.FunDapterUtils.showData(FunDapterUtils.java:84) 
                       at com.amigold.fundapter.FunDapter.showData(FunDapter.java:123) 
                       at com.amigold.fundapter.FunDapter.getView(FunDapter.java:107) 
                       at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:194) 
                       at android.widget.Spinner.onMeasure(Spinner.java:580) 
                       at android.support.v7.widget.AppCompatSpinner.onMeasure(AppCompatSpinner.java:410) 
                       at android.view.View.measure(View.java:18788) 
                       at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:715) 
                       at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:607) 
                       at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1238) 
                       at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:672) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                       at android.support.v7.internal.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:124) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465) 
                       at android.widget.LinearLayout.measureVertical(LinearLayout.java:748) 
                       at android.widget.LinearLayout.onMeasure(LinearLayout.java:630) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465) 
                       at android.widget.LinearLayout.measureVertical(LinearLayout.java:748) 
                       at android.widget.LinearLayout.onMeasure(LinearLayout.java:630) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                       at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2643) 
                       at android.view.View.measure(View.java:18788) 
                       at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2100) 
                       at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1216) 
                       at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1452) 
                       at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107) 
                       at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013) 
                       at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858) 
                       at android.view.Choreographer.doCallbacks(Choreographer.java:670) 
                       at android.view.Choreographer.doFrame(Choreographer.java:606) 
                       at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844) 
                       at android.os.Handler.handleCallback(Handler.java:739) 
                       at android.os.Handler.dispatchMessage(Handler.java:95) 
                       at android.os.Looper.loop(Looper.java:148) 
                       at android.app.ActivityThread.main(ActivityThread.java:5417) 
                       at java.lang.reflect.Method.invoke(Native Method) 
                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

FunDaptor.java：

/** 
* A generic adapter that takes a BindDictionary and data and shows them. Does 
* basic validation for you for all fields and also handles the ViewHolder 
* pattern. 
* 
* @param <T> 
* @author Ami G 
*/ 
public class FunDapter<T> extends BaseAdapter implements Filterable { 

protected ArrayList<T> mDataItems; 
protected ArrayList<T> mOrigDataItems; 
protected final Context mContext; 
private final int mLayoutResource; 
private final BindDictionary<T> mBindDictionary; 
private int oddColorRes; 
private int evenColorRes; 
private FunDapterFilter<T> funDapterFilter; 
private Filter mFilter; 

/** 
* A generic adapter that takes a BindDictionary and data and shows them. 
* Does basic validation for you for all fields and also handles the 
* ViewHolder pattern. 
* 
* @param context 
* @param dataItems  - An arraylist of model items 
* @param layoutResource - resource ID of a layout to inflate for each item. (Example: 
*      R.layout.list_item) 
* @param dictionary  - The dictionary that will match between fields and data. 
*/ 
public FunDapter(Context context, ArrayList<T> dataItems, int layoutResource, 
       BindDictionary<T> dictionary) { 
    this.mContext = context; 
    this.mDataItems = dataItems; 
    this.mOrigDataItems = dataItems; 
    this.mLayoutResource = layoutResource; 
    this.mBindDictionary = dictionary; 
} 

/** 
* Replace the current dataset with a new one and refresh the views. This 
* will call notifyDataSetChanged() for you. 
* 
* @param dataItems 
*/ 
public void updateData(ArrayList<T> dataItems) { 
    this.mDataItems = dataItems; 
    this.mOrigDataItems = dataItems; 
    notifyDataSetChanged(); 
} 

@Override 
public int getCount() { 
    if (mDataItems == null || mBindDictionary == null) return 0; 

    return mDataItems.size(); 
} 

@Override 
public T getItem(int position) { 
    return mDataItems.get(position); 
} 

@Override 
public long getItemId(int position) { 
    return position; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 

    // Inflate a new view or use a recycled view. 
    View v = convertView; 
    GenericViewHolder holder; 
    if (null == v) { 
     LayoutInflater vi = 
       (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     v = vi.inflate(mLayoutResource, null); 
     holder = new GenericViewHolder(); 
     holder.root = v; 

     // init the sub views and put them in a holder instance 
     FunDapterUtils.initViews(v, holder, mBindDictionary); 

     v.setTag(holder); 
    } else { 
     holder = (GenericViewHolder) v.getTag(); 
    } 

    // Show the data 
    final T item = getItem(position); 
    showData(item, holder, position); 

    return v; 
} 

private void showData(T item, GenericViewHolder holder, int position) { 

    // handles alternating background colors if selected 
    if (oddColorRes > 0 && evenColorRes > 0) { 
     if (position % 2 == 0) { 
      holder.root.setBackgroundColor(mContext.getResources().getColor(evenColorRes)); 
     } else { 
      holder.root.setBackgroundColor(mContext.getResources().getColor(oddColorRes)); 
     } 
    } 

    FunDapterUtils.showData(item, holder, position, mBindDictionary); 
} 

public FunDapter<T> setAlternatingBackground(int oddColorRes, int evenColorRes) { 

    if (oddColorRes <= 0 || evenColorRes <= 0) { 
     throw new IllegalArgumentException("Color parameters are illegal"); 
    } 

    this.oddColorRes = oddColorRes; 
    this.evenColorRes = evenColorRes; 

    return this; 
} 

@Override 
public Filter getFilter() { 
    return mFilter; 
} 

/** 
* Use this method to enable filtering in the adapter. 
* 
* @param filter - a filter implementation for your adapter. 
*/ 
public void initFilter(FunDapterFilter<T> filter) { 

    if (filter == null) 
     throw new IllegalArgumentException("Cannot pass a null filter to FunDapter"); 

    this.funDapterFilter = filter; 

    mFilter = new Filter() { 

     @Override 
     protected void publishResults(CharSequence constraint, FilterResults results) { 

      @SuppressWarnings("unchecked") ArrayList<T> list = (ArrayList<T>) results.values; 

      if (results.count == 0) { 
       resetData(); 
      } else { 
       mDataItems = list; 
      } 

      notifyDataSetChanged(); 
     } 

     @Override 
     protected FilterResults performFiltering(CharSequence constraint) { 

      FilterResults results = new FilterResults(); 
      if (constraint == null || constraint.length() == 0) { 

       // No constraint - no point in filtering. 
       results.values = mOrigDataItems; 
       results.count = mOrigDataItems.size(); 
      } else { 
       // Perform the filtering operation 

       ArrayList<T> filter = 
         funDapterFilter.filter(constraint.toString(), mOrigDataItems); 

       results.count = filter.size(); 
       results.values = filter; 

      } 

      return results; 
     } 
    }; 
} 

public void resetData() { 
    mDataItems = mOrigDataItems; 
}

}

助けていただけたら助かります。おかげ

出典

2016-04-01 Anthony Galpo

クラッシュログを貼り付けてください。 –

@ShadabAnsari私はそれを入れました。 –

貼り付けFunDapterコード。 –

@Override 
public void processFinish(String s) { 
    projectsList = new JsonConverter<ProjectNames>().toArrayList(s, ProjectNames.class); 
    Log.d(LOG, "processFinish: " + s); 
    BindDictionary<ProjectNames> dict = new BindDictionary<ProjectNames>(); 

    dict.addStringField(R.id.tvProjectName, new StringExtractor<ProjectNames>() { 

     @Override 
     public String getStringValue(ProjectNames projects, int position) { 
      return projects.projectname; 
     } 
    }); 

    FunDapter<ProjectNames> adaptor = new FunDapter<>(MainPage.this, projectsList, R.layout.spinner, dict); 
    spinner1 = (Spinner) findViewById(R.id.spFirstChoice); 
    spinner1.setAdapter(adaptor); 
}

}で間違ったidを持っているので、それはおそらくです。私はsupport_simple_spinner_dropdown_itemではなくxmlファイルスピナーを呼び出しました。返信してくれてありがとう！

出典

2016-04-02 01:09:59

LogcatはFunDaptorUtilsに向けて私を指摘：

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setVisibility(int)' on a null object reference 
    at com.amigold.fundapter.FunDapterUtils.handleStringFields(FunDapterUtils.java:231)

FunDaptorUtils内部では、ライブラリが故障し、論理持って見ることができます。

// fill data 
if (!TextUtils.isEmpty(stringValue) && view != null) { 
    view.setText(stringValue); 
    view.setVisibility(View.VISIBLE); 
} else { 
    view.setVisibility(field.visibilityIfNull); 
}

これは間違っているのため、ときにアクセスするview == nullelseブロック試行view.setVisibility()しかし、私たちはすでにviewがnullであることを知っていますので、NullPointerException ...
コードを切り替え：

if (view != null) { 
    if (!TextUtils.isEmpty(stringValue)) { 
      view.setText(stringValue); 
      view.setVisibility(View.VISIBLE); 
    } else { 
      view.setVisibility(field.visibilityIfNull); 
    } 
}

しかし本当問題がある：なぜこのTextView nullはありますか？あなたは私が間違ったxmlファイルを置く

support_simple_spinner_dropdown_item.xml

出典

2016-04-02 00:24:15 Sam

SpinnerにJSON ArrayListを設定する

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