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我正在構建一個涉及Recyclerview的應用程序。我想在點擊每個項目（編輯該項目的內容）時啓動一個對話框，但現在，我只想在每個項目單擊該項目的唯一ID時顯示一個Toast消息。有在stackoverflow的例子，但他們都是不同的方法，我不知道如何實現他們到我的應用程序（我還在學習Recyclerviews）。這是我在處理點擊動作時的嘗試，但它沒有做任何事情：如何處理項目onClick我的Recyclerview
recyclerView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(addTaskActivity, view + " is clicked", Toast.LENGTH_SHORT).show();
}
});
什麼也沒有發生。以下是我的MainActivity.java和CustomCursorAdapter.java文件。
public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {
private static final String TAG = MainActivity.class.getSimpleName();
private static final int LOADER_ID = 0;
private CustomCursorAdapter customCursorAdapter;
RecyclerView recyclerView;
private AddTaskActivity addTaskActivity;
private Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recyclerViewTasks);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
customCursorAdapter = new CustomCursorAdapter(this);
recyclerView.setAdapter(customCursorAdapter);
recyclerView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(addTaskActivity, view + " is clicked", Toast.LENGTH_SHORT).show();
}
});
new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) {
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
return false;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int swipeDir) {
int id = (int) viewHolder.itemView.getTag();
String itemId = Integer.toString(id);
Uri uri = TaskContract.TaskEntry.CONTENT_URI;
uri = uri.buildUpon().appendPath(itemId).build();
getContentResolver().delete(uri, null, null);
getSupportLoaderManager().restartLoader(LOADER_ID, null, MainActivity.this);
}
}).attachToRecyclerView(recyclerView);
FloatingActionButton floatingActionButton = (FloatingActionButton) findViewById(R.id.fab_btn);
floatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent addTaskIntent = new Intent(MainActivity.this, AddTaskActivity.class);
startActivity(addTaskIntent);
}
});
getSupportLoaderManager().initLoader(LOADER_ID, null, this);
}
@Override
protected void onResume() {
super.onResume();
getSupportLoaderManager().restartLoader(LOADER_ID, null, this);
}
@Override
public Loader<Cursor> onCreateLoader(int id, final Bundle loaderArgs) {
return new AsyncTaskLoader<Cursor>(this) {
Cursor cursor = null;
@Override
protected void onStartLoading() {
if (cursor != null) {
deliverResult(cursor);
} else {
forceLoad();
}
}
@Override
public Cursor loadInBackground() {
try {
return getContentResolver().query(TaskContract.TaskEntry.CONTENT_URI,
null,
null,
null,
TaskContract.TaskEntry.COLUMN_PRIORITY);
} catch (Exception e) {
Log.e(TAG, "Failed to load data.");
e.printStackTrace();
return null;
}
}
public void deliverResult(Cursor data) {
cursor = data;
super.deliverResult(data);
}
};
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
customCursorAdapter.swapCursor(data);
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
customCursorAdapter.swapCursor(null);
}
}
這是我的自定義適配器：
public class CustomCursorAdapter extends RecyclerView.Adapter<CustomCursorAdapter.TaskViewHolder>{
private Cursor cursor;
private Context con;
public CustomCursorAdapter(Context context) {
this.con = context;
}
@Override
public TaskViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(con).inflate(R.layout.task_layout, parent, false);
return new TaskViewHolder(view);
}
@Override
public void onBindViewHolder(TaskViewHolder holder, int position) {
int index = cursor.getColumnIndex(TaskContract.TaskEntry._ID);
int descriptionOfIndex = cursor.getColumnIndex(TaskContract.TaskEntry.COLUMN_DESCRIPTION);
int priorityofIndex = cursor.getColumnIndex(TaskContract.TaskEntry.COLUMN_PRIORITY);
cursor.moveToPosition(position);
final int id = cursor.getInt(index);
String description = cursor.getString(descriptionOfIndex);
int priority = cursor.getInt(priorityofIndex);
holder.itemView.setTag(id);
holder.taskDescriptionView.setText(description);
String priorityString = "" + priority;
holder.priorityView.setText(priorityString);
GradientDrawable priorityCircle = (GradientDrawable) holder.priorityView.getBackground();
int priorityColor = getPriorityColor(priority);
priorityCircle.setColor(priorityColor);
}
private int getPriorityColor(int priority) {
int priorityColor = 0;
switch(priority) {
case 1: priorityColor = ContextCompat.getColor(con, R.color.materialRed);
break;
case 2: priorityColor = ContextCompat.getColor(con, R.color.materialOrange);
break;
case 3: priorityColor = ContextCompat.getColor(con, R.color.materialYellow);
break;
default: break;
}
return priorityColor;
}
@Override
public int getItemCount() {
if (cursor == null) {
return 0;
}
return cursor.getCount();
}
public Cursor swapCursor(Cursor c) {
if (cursor == c) {
return null;
}
Cursor temp = cursor;
this.cursor = c;
if (c != null) {
this.notifyDataSetChanged();
}
return temp;
}
public class TaskViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView taskDescriptionView;
TextView priorityView;
public TaskViewHolder(View itemView) {
super(itemView);
taskDescriptionView = (TextView) itemView.findViewById(R.id.taskDescription);
priorityView = (TextView) itemView.findViewById(R.id.priorityTextView);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View view) {
int position = getLayoutPosition();
}
}
}
編輯試過這種實現，但我不能從另一個調用活性的方法：
public class TaskViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView taskDescriptionView;
TextView priorityView;
public TaskViewHolder(View itemView) {
super(itemView);
taskDescriptionView = (TextView) itemView.findViewById(R.id.taskDescription);
priorityView = (TextView) itemView.findViewById(R.id.priorityTextView);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View view) {
int position = getLayoutPosition();
addTaskActivity.onClickAddTask(view);
}
}
代碼這已經一再要求實現它。當你研究如何做時，你看到了什麼？ –
一種簡單的方法是編寫onClick例如'android：onClick =「myOnClick」'在相應視圖的XMl中，然後在調用RecyclerView的活動中使用'public void myOnClick（View view）{....}'編寫方法。 – MikeT
@ cricket_007基本上與我的代碼並沒有緊密結合的實現，因爲我遵循規範和框架代碼進行工作。 –