如何使用自定义适配器中的复选框

问题描述：

我正在使用复选框，它在我的自定义Adapter.I中使用活动中的接口在另一个ListView中发送复选框文本我面临的问题是当我将该项添加到复选框并检查复选框的应用程序得到停止工作..但是当我重新打开应用程序，并尝试再次检查其workfine.when我尝试添加一个新项目复选框相同的问题发生时，反之亦然如何使用自定义适配器中的复选框

Logcat错误：

java.lang.NullPointerException: Attempt to invoke interface method 'void com.advoco.notepad.ListAdapter$onItemChecked.onItemClick(int)' on a null object reference 
                    at com.advoco.notepad.ListAdapter$1.onCheckedChanged(ListAdapter.java:51) 
                    at android.widget.CompoundButton.setChecked(CompoundButton.java:156) 
                    at android.widget.CompoundButton.toggle(CompoundButton.java:115) 
                    at android.widget.CompoundButton.performClick(CompoundButton.java:120) 
                    at android.view.View$PerformClick.run(View.java:22429) 
                    at android.os.Handler.handleCallback(Handler.java:751) 
                    at android.os.Handler.dispatchMessage(Handler.java:95) 
                    at android.os.Looper.loop(Looper.java:154) 
                    at android.app.ActivityThread.main(ActivityThread.java:6119) 
                    at java.lang.reflect.Method.invoke(Native Method) 
                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 


public class ListAdapter extends ArrayAdapter<NoteDone> { 
Context context; 
LayoutInflater inflater; 
List<NoteDone> noteDones; 
private onItemChecked onClick; 
public ListAdapter(Context context,int resource,List<NoteDone> noteDones) { 
    super(context, resource,noteDones); 
    this.context = context; 
    this.noteDones = noteDones; 
    inflater = LayoutInflater.from(context); 
} 
private class ViewHolder { 
    TextView notDone; 
    CheckBox checkBox; 
} 
public interface onItemChecked{ 
    void onItemClick(int position); 
} 
public View getView(final int position, View view, ViewGroup parent) { 
    final ListAdapter.ViewHolder holder; 
    final NoteDone model = noteDones.get(position); 
    if (view == null) { 
     holder = new ListAdapter.ViewHolder(); 
     view = inflater.inflate(R.layout.notdone, null); 
     holder.checkBox = (CheckBox) view.findViewById(R.id.checkBox); 
     view.setTag(holder); 
    } else { 
     holder = (ListAdapter.ViewHolder) view.getTag(); 
    } 
    holder.checkBox.setText(model.getTask()); 
    holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 
     @Override 
     public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 
      onClick.onItemClick(position); 
     } 
    }); 
    return view; 
} 
public void setOnClick(onItemChecked onClick) 
{ 
    this.onClick=onClick; 
} 
}

我的活动类：

public class ToDo extends AppCompatActivity implements 
ListAdapter.onItemChecked{ 
DBhelper dBhelper; 
ListView lstTask,listView; 
List<NoteDone> taskList,tasklist2; 
ListAdapter listAdapter; 
ListAdapter2 listAdapter2; 
SQLiteDatabase sqLiteDatabase; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.todo); 
    lstTask = (ListView)findViewById(R.id.nd); 
    listView = (ListView)findViewById(R.id.done); 
    LoadTask(); 
    LoadTask2(); 
    listAdapter.setOnClick(this); 
    /*lstTask.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      String name = taskList.get(position).getTask(); 
      dBhelper.insertNewTask2(name); 
      dBhelper.deleteTask(name); 
      LoadTask(); 
      LoadTask2(); 
     } 
    });*/ 
} 
public void LoadTask() { 
    dBhelper = new DBhelper(getApplicationContext()); 
    sqLiteDatabase = dBhelper.getReadableDatabase(); 
    taskList = dBhelper.getTaskList(sqLiteDatabase); 
    if (taskList != null) { 
     listAdapter = new ListAdapter(getApplicationContext(), R.layout.notdone, taskList); 
     lstTask.setAdapter(listAdapter); 
    } 
} 
public void LoadTask2() { 
    dBhelper = new DBhelper(getApplicationContext()); 
    sqLiteDatabase = dBhelper.getReadableDatabase(); 
    tasklist2 = dBhelper.getTaskList2(sqLiteDatabase); 
    if (tasklist2 != null) { 
     listAdapter2 = new ListAdapter2(getApplicationContext(), R.layout.done, tasklist2); 
     listView.setAdapter(listAdapter2); 
    } 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    MenuInflater inflater = getMenuInflater(); 
    inflater.inflate(R.menu.todo_menu, menu); 
    return super.onCreateOptionsMenu(menu); 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    switch (item.getItemId()){ 
     case R.id.action_add_task: 
      final EditText taskEditText = new EditText(this); 
      AlertDialog dialog = new AlertDialog.Builder(this) 
        .setTitle("Add New Task") 
        .setMessage("What do you want to do next?") 
        .setView(taskEditText) 
        .setPositiveButton("Add", new DialogInterface.OnClickListener() { 
         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          String task = String.valueOf(taskEditText.getText()); 
          dBhelper.insertNewTask(task); 
          LoadTask(); 
         } 
        }) 
        .setNegativeButton("Cancel",null) 
        .create(); 
      dialog.show(); 
      return true; 
    } 
    return super.onOptionsItemSelected(item); 
} 

@Override 
public void onItemClick(int position) { 
    String name = taskList.get(position).getTask(); 
    dBhelper.insertNewTask2(name); 
    dBhelper.deleteTask(name); 
    LoadTask(); 
    LoadTask2(); 
} 
}

显示活动类 – DEADMC

更新了我的问题 –

答

listAdapter.setOnClick(this);

此行应列入LoadTask（）方法。删除 listAdapter.setOnClick（this）;来自onCreate（）。在LoadTask（）上添加这个。

lstTask.setAdapter(listAdapter); 
listAdapter.setOnClick(this);

工作就像一个魅力:)谢谢 –

感谢队友。很高兴它完美地工作，并且接受它。 –

答

问题与您的炎症视图。更改以下

inflater.inflate(R.layout.notdone, null);

要

inflater.inflate(R.layout.notdone, parent, false);

希望这将设置适配器后解决问题

没有没有工作。 –

如何使用自定义适配器中的复选框

相关推荐