No se puede configurar OnCheckedChangeListener en una casilla de verificación

Question

Estoy tratando de establecer un OnCheckedChangeListener en un CheckBox pero mi aplicación se cierra en el tiempo de ejecución. También traté de configurar oyentes para mi TextView y todavía obtengo el mismo resultado. ¿Alguien puede ayudar?

import android.app.ListActivity; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.DialogInterface.OnClickListener; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ArrayAdapter; 
import android.widget.CheckBox; 
import android.widget.CompoundButton; 
import android.widget.CompoundButton.OnCheckedChangeListener; 
import android.widget.ImageView; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 

public class ListViewActivity extends ListActivity implements OnCheckedChangeListener { 

TextView label; 
CheckBox checkBox; 

public class MyCustomAdapter extends ArrayAdapter<String> { 


public MyCustomAdapter(Context context, int textViewResourceId, 
String[] objects) { 
super(context, textViewResourceId, objects); 

// TODO Auto-generated constructor stub 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
// TODO Auto-generated method stub 
//return super.getView(position, convertView, parent); 

View row = convertView; 

if(row==null){ 
LayoutInflater inflater=getLayoutInflater(); 
row=inflater.inflate(R.layout.main, parent, false); 

} 


label=(TextView)row.findViewById(R.id.weekofday); 
label.setText(month[position]); 
checkBox=(CheckBox)row.findViewById(R.id.checkBox); 


return row; 
} 
} 

String[] month = { 
"January", "February", "March", "April", 
"May", "June", "July", "August", 
"September", "October", "November", "December" 
}; 

/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
// setContentView(R.layout.main); 
/*setListAdapter(new ArrayAdapter<String>(this, 
    R.layout.row, R.id.weekofday, DayOfWeek));*/ 


    setListAdapter(new MyCustomAdapter(ListViewActivity.this, R.layout.main, month)); 

    checkBox.setOnCheckedChangeListener(this); //my application exits here!!!! 

} 





@Override 
public void onCheckedChanged(CompoundButton arg0, boolean arg1) { 
// TODO Auto-generated method stub 
//Toast.makeText(getApplicationContext(), "box checked", Toast.LENGTH_LONG); 

} 


} 

Answer 1

No se puede establecer el oyente para su CheckBox del ListView como que (probablemente arrojará un NullPointerException), en lugar de establecer el oyente en el método getView() (también se tendrá que mantener el estado CheckBox para que no termines con el estado de filas extrañas). Abajo es un ejemplo:

public class ListViewActivity extends ListActivity { 

    public class MyCustomAdapter extends ArrayAdapter<String> { 

     private ArrayList<Boolean> status = new ArrayList<Boolean>(); 

     public MyCustomAdapter(Context context, int textViewResourceId, 
       String[] objects) { 
      super(context, textViewResourceId, objects); 
      for (int i = 0; i < objects.length; i++) { 
       status.add(false); 
      } 
     } 

     @Override 
     public View getView(final int position, View convertView, 
       ViewGroup parent) { 
      View row = convertView; 
      if (row == null) { 
       LayoutInflater inflater = getLayoutInflater(); 
       row = inflater.inflate(R.layout.adapters_listviewactivity_row, 
         parent, false); 
      } 

      TextView label = (TextView) row.findViewById(R.id.weekofday); 
      label.setText(month[position]); 
      CheckBox checkBox = (CheckBox) row.findViewById(R.id.checkBox); 
      checkBox.setOnCheckedChangeListener(new OnCheckedChangeListener() { 

       @Override 
       public void onCheckedChanged(CompoundButton buttonView, 
         boolean isChecked) { 
        Toast.makeText(getApplicationContext(), "" + position, 
          Toast.LENGTH_SHORT).show(); 
        if (isChecked) { 
         status.set(position, true); 
        } else { 
         status.set(position, false); 
        } 
       } 
      }); 
      checkBox.setChecked(status.get(position)); 
      return row; 
     } 
    } 

    String[] month = { "January", "February", "March", "April", "May", "June", 
      "July", "August", "September", "October", "November", "December" }; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setListAdapter(new MyCustomAdapter(ListViewActivity.this, 
       R.layout.main, month)); 
    } 

} 

Para el TextView que tendrá que hacer lo mismo.

Answer 2

Implementar CheckBox Listener para su clase de esta manera, especialmente si usted tiene más de un CheckBox de tratar, que puede manejar en bloques de casos de conmutación y hace su código más limpio:

public class MyClass extends AppCompatActivity implements 
    CompoundButton.OnCheckedChangeListener,{ 

     CheckBox myCheckBox; 
    } 

En su método onCreate() poner esto:

myCheckBox = (CheckBox)findViewById(R.Id.myCheckBoxName_in_XML_layout); 
    mmyCheckBox.setOnCheckedChangeListener(this); 

Listern para su vista de eventos como esta casilla:

@Override 
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 

    switch (buttonView.getId()){ 
     case R.id.myCheckBoxName_in_XML_layout: 

      if(isChecked == true) { 
       Toast.makeText(this, "Checked", Toast.LENGTH_SHORT).show(); 
      } else{ 
        Toast.makeText(this, "Unchecked", Toast.LENGTH_SHORT).show(); 
        } 

      break; 
     } 

     } 

Answer 3

public class MainActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener { 
List<String> mList = new ArrayList<>(); 
CheckBox android, java, python, php, unity3D; 
Button submitButton; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    android = (CheckBox) findViewById(R.id.androidCheckBox); 
    android.setOnCheckedChangeListener(this); 
    java = (CheckBox) findViewById(R.id.javaCheckBox); 
    java.setOnCheckedChangeListener(this); 
    python = (CheckBox) findViewById(R.id.pythonCheckBox); 
    python.setOnCheckedChangeListener(this); 
    php = (CheckBox) findViewById(R.id.phpCheckBox); 
    php.setOnCheckedChangeListener(this); 
    unity3D = (CheckBox) findViewById(R.id.unityCheckBox); 
    unity3D.setOnCheckedChangeListener(this); 

    submitButton = (Button) findViewById(R.id.submitButton); 
    submitButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Log.e("ArrayList Values*******",mList.toString()); 
     } 
    }); 

} 

@Override 
public void onCheckedChanged(CompoundButton compoundButton, boolean b) { 
    switch (compoundButton.getId()) { 
     case R.id.androidCheckBox: 
      if (android.isChecked()) { 
       mList.add(String.valueOf(android.getText())); 
       Log.e("Android*******",mList.toString()); 
      } 
      else { 
        mList.remove(android.getText()); 
      } 
      break; 

     case R.id.javaCheckBox: 
      if (java.isChecked()) { 
       mList.add(String.valueOf(java.getText())); 
       Log.e("Java*******",mList.toString()); 
      } 
      else { 
       mList.remove(java.getText()); 
      } 
      break; 

     case R.id.phpCheckBox: 
      if (php.isChecked()) { 
       mList.add(String.valueOf(php.getText())); 
       Log.e("PHP*******",mList.toString()); 
      } 
      else { 
       mList.remove(php.getText()); 
      } 
      break; 

     case R.id.pythonCheckBox: 
      if (python.isChecked()){ 
       mList.add(String.valueOf(python.getText())); 
       Log.e("Python*******",mList.toString()); 
      } 
      else { 
       mList.remove(python.getText()); 
      } 
      break; 

     case R.id.unityCheckBox: 
      if (unity3D.isChecked()){ 
       mList.add(String.valueOf(unity3D.getText())); 
       Log.e("Unity*******",mList.toString()); 
      } 
      else { 
       mList.remove(unity3D.getText()); 
      } 
      break; 
     } 
    } 
}