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android - EditText 和 TextView 中的 Null

问题描述

当我想将数据从列表传递到任何文本视图或编辑视图到片段时，我遇到了这个问题：尝试在空对象引用上调用虚拟方法 'void android.widget.EditText.setText(java.lang.CharSequence)' 我是使用 Butterknife，这是在 onCreateView 中启动的。怎么了？

片段中的方法：

@Override
public void itemData(int position, List<Task> tasks) {

    Task task = tasks.get(position);
    taskID = task.getId();
    String taskTexT = task.getDate();
    titleEdit.setText(task.getText());

    Log.d(TAG, "EDIT FRAGMENT " + position + task + taskTexT);

}

片段中的黄油刀：

@BindView(R.id.time_edit) TextView timeEdit;
@BindView(R.id.date_edit) TextView dateEdit;
@BindView(R.id.title_edit) EditText titleEdit;
@BindView(R.id.save_edit_button) Button saveEditButton;

和 XML 文件：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/edit_fragment">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="300dp"
    android:background="@color/colorPrimaryDark">

    <EditText
        android:id="@+id/title_edit"
        android:layout_width="330dp"
        android:layout_height="60dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="35dp"
        android:backgroundTint="#FFF"
        android:textColor="#FFF" />

    <TextView
        android:id="@+id/date_edit"
        android:layout_width="130dp"
        android:layout_height="40dp"
        android:layout_alignTop="@+id/and"
        android:layout_toStartOf="@+id/and"
        android:clickable="true"
        android:focusable="true"
        android:gravity="center"
        android:hint="Select date"
        android:textColor="#FFF"
        android:textColorHint="#FFF"
        android:textSize="18sp" />

    <View
        android:id="@+id/line"
        android:layout_width="320dp"
        android:layout_height="1dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="119dp"
        android:background="#FFF" />

    <TextView
        android:id="@+id/time_edit"
        android:layout_width="132dp"
        android:layout_height="40dp"
        android:layout_above="@+id/line"
        android:layout_toEndOf="@+id/and"
        android:clickable="true"
        android:focusable="true"
        android:gravity="center"
        android:hint="Select time"
        android:textAlignment="center"
        android:textColor="#FFF"
        android:textColorHint="#FFF"
        android:textSize="18sp" />

    <TextView
        android:id="@+id/and"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:layout_above="@+id/line"
        android:layout_centerHorizontal="true"
        android:gravity="center"
        android:text="and"
        android:textColor="#FFF"
        android:textSize="18sp" />

    <Button
        android:id="@+id/save_edit_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="36dp"
        android:text="EDIT"/>


</RelativeLayout>

编辑片段：

public class EditFragment extends Fragment implements IRecyclerItemData {

private static final String TAG = "EditFragment";

@BindView(R.id.time_edit) TextView timeEdit;
@BindView(R.id.date_edit) TextView dateEdit;
@BindView(R.id.title_edit) EditText titleEdit;
@BindView(R.id.save_edit_button) Button saveEditButton;

private DatePickerDialog.OnDateSetListener mDateEditListener;
private TimePickerDialog.OnTimeSetListener mTimeEditListener;

List<Task> tasks;
String taskID;
RealmHelper realmHelper;
Realm realm;


@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.edit_fragment, container, false);

    ButterKnife.bind(this, view);
    ((MainActivity) getActivity()).hideFloatingActionButton();


    Realm.init(getActivity());
    RealmConfiguration configuration = new RealmConfiguration
            .Builder()
            .deleteRealmIfMigrationNeeded()
            .build();
    realm = Realm.getInstance(configuration);

    realmHelper = new RealmHelper(realm);
    tasks = new ArrayList<>();
    tasks = realmHelper.getAllTasks();

    mDateEditListener = new DatePickerDialog.OnDateSetListener() {
        @Override
        public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
            month = month + 1;
            Log.d(TAG, "onDataEditSet: dd/mm/yyyy: " + year + "/" + month + "/" + dayOfMonth);
            String date = dayOfMonth + "/" + month + "/" + year;
            dateEdit.setText(date);
        }
    };

    mTimeEditListener = new TimePickerDialog.OnTimeSetListener() {
        @Override
        public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
            Log.d(TAG, "onTimeEditSet: hh/mm: " + hourOfDay + "/" + minute);
            String time = hourOfDay + ":" + minute;
            timeEdit.setText(time);

        }
    };

    return view;
}


@OnClick(R.id.date_edit)
public void onEditDateClick() {
    Calendar calendar = Calendar.getInstance();
    int year = calendar.get(Calendar.YEAR);
    int month = calendar.get(Calendar.MONTH);
    int day = calendar.get(Calendar.DAY_OF_MONTH);

    DatePickerDialog dialog = new DatePickerDialog(getActivity(), android.R.style.Theme_Holo_Light_Dialog_MinWidth, mDateEditListener,
            year, month, day);
    dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
    dialog.show();
}


@SuppressLint("ResourceType")
@OnClick(R.id.time_edit)
public void onEditTimeClick() {
    Calendar calendar = Calendar.getInstance();
    int hourOfDay = calendar.get(Calendar.HOUR_OF_DAY);
    int minute = calendar.get(Calendar.MINUTE);

    TimePickerDialog dialog = new TimePickerDialog(getActivity(), android.R.style.Theme_Holo_Light_Dialog_MinWidth, mTimeEditListener,
            hourOfDay, minute, DateFormat.is24HourFormat(getActivity()));
    dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
    dialog.show();
}


@OnClick(R.id.save_edit_button)
public  void onEditSaveClick() {

}


@Override
public void itemData(int position, List<Task> tasks) {

    Task task = tasks.get(position);
    taskID = task.getId();
    String taskTexT = task.getDate();
    titleEdit.setText(task.getText());

    Log.d(TAG, "EDIT FRAGMENT " + position + task + taskTexT);

}

}

这是我调用 itemData 的 RV Adapter 的一部分：

 @Override
public void onBindViewHolder(@NonNull final TaskViewHolder holder, @SuppressLint("RecyclerView") final int position) {
   final Task task = tasks.get(position);
   holder.textItem.setText(task.getText());
   holder.dateItem.setText(task.getDate());
   holder.timeItem.setText(task.getTime());
   holder.deleteButton.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View v) {
           int position = holder.getAdapterPosition();
           callback.onDeleteClick(position);
           notifyItemRemoved(holder.getAdapterPosition());
           Log.d(TAG, "DELETE_CLICK " + holder.getAdapterPosition());
       }

   });

   holder.editButton.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View v) {
           int position = holder.getAdapterPosition();
           callback.onEditClick(position);
           callback2.itemData(position, tasks);


       }
   });

}

主要活动：

public class MainActivity extends AppCompatActivity implements IRecyclerItemClickListener {

@Nullable
@BindView(R.id.floating_button) FloatingActionButton floatingButton;

RecyclerView recyclerView;
MainAdapter mainAdapter;
EditFragment editFragment = new EditFragment();

Realm realm;
RealmHelper realmHelper;
List<Task> tasks;
String taskID;

private static final String TAG = "MainActivity";


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ButterKnife.bind(this);

    recyclerView = findViewById(R.id.recycler_view);
    RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
    recyclerView.setLayoutManager(layoutManager);

    Realm.init(this);
    RealmConfiguration configuration = new RealmConfiguration
            .Builder()
            .deleteRealmIfMigrationNeeded()
            .build();
    realm = Realm.getInstance(configuration);

    realmHelper = new RealmHelper(realm);
    tasks = new ArrayList<>();
    tasks = realmHelper.getAllTasks();

    mainAdapter = new MainAdapter(tasks, this, new IRecyclerItemData() {
        @Override
        public void itemData(int position, List<Task> tasks) {
            editFragment.itemData(position, tasks);
        }
    });
    recyclerView.setAdapter(mainAdapter);
    recyclerView.setHasFixedSize(true);

}


@Optional
@OnClick(R.id.floating_button)
public void onClick() {
    android.app.Fragment fragment = new TaskFragment();

    FragmentTransaction transaction = getFragmentManager().beginTransaction();
    transaction.replace(R.id.main_activity, fragment);
    transaction.addToBackStack(null);
    transaction.commit();
}


public void showFloatingActionButton() {
    floatingButton.show();
}


public void hideFloatingActionButton() {
    floatingButton.hide();
}


@Override
public void onBackPressed() {
    super.onBackPressed();
    showFloatingActionButton();
    recyclerView.removeAllViews();
}


@Override
protected void onDestroy() {
    realm.close();
    super.onDestroy();
}


@Override
public void onDeleteClick(int position) {
        Task task = tasks.get(position);
        taskID = task.getId();
        if (taskID != null) {
            realmHelper.deleteTask(taskID);
            Log.d(TAG, "ON DELETE CLICK " + taskID);

            Toast.makeText(getApplicationContext(), "Task removed", Toast.LENGTH_LONG).show();
        }
}


@Override
public void onEditClick(int position) {
    Fragment fragment = new EditFragment();

    FragmentTransaction transaction = getFragmentManager().beginTransaction();
    transaction.replace(R.id.main_activity, fragment);
    transaction.addToBackStack(null);
    transaction.commit();
}

}

标签： androidbutterknife

解决方案

确保您正在调用ButterKnife.bind(this, view)进行初始化。

@BindView(R.id.time_edit)
TextView timeEdit;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.your_layout, container, false);
        ButterKnife.bind(this, view);
        return view;
    }

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