在 MainActivity 中，我有一个响应长按的 ContextMenu 和一个响应常规点击的常规 OnItemClickListener。
在实际上类似于 MainActivity 的 TaskActivity 上，我也有一个响应长按的 ContextMenu，但是当尝试设置 OnItemClickListener 时， ListView 中的项目不响应(它们确实响应长按).
我错过了什么？我尝试了各种方法，例如将可点击状态更改为 false 等等 - 它们都不起作用。这是有道理的，因为我在 MainActivity XML 中没有它们，但它确实在那里工作。
主要 Activity 代码:
公共(public)类 MainActivity 扩展 AppCompatActivity {
final Context context = this;
public static final int SIGN_IN = 1;
public static String currentTaskListId;
public static String currentUserId;
private TaskListAdapter mTaskListAdapter;
//TextView that is displayed when the list is empty//
private TextView mEmptyStateTextView;
//The loading indicator //
private View loadingIndicator;
// Firebase instance variables
private FirebaseAuth mFirebaseAuth;
private FirebaseAuth.AuthStateListener mAuthStateListener;
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mTaskListDatabaseReference;
private ChildEventListener mChildEventListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set the content of the activity to use the activity_main.xml layout file - the task lists
setContentView(R.layout.activity_main);
// Initialize Firebase components
mFirebaseAuth = FirebaseAuth.getInstance();
mFirebaseDatabase = FirebaseDatabase.getInstance();
//Initialize firebase authentication
mAuthStateListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
// user is signed in
currentUserId=user.getUid();
onSignedInInitialize(user.getUid());
} else {
// user is signed out
onSignedOutCleanup();
startActivityForResult(
AuthUI.getInstance()
.createSignInIntentBuilder()
.setIsSmartLockEnabled(false)
.setAvailableProviders(Arrays.asList(
new AuthUI.IdpConfig.EmailBuilder().build(),
new AuthUI.IdpConfig.GoogleBuilder().build()))
.setTosAndPrivacyPolicyUrls("https://superapp.example.com/terms-of-service.html",
"https://superapp.example.com/privacy-policy.html")
.build(),
SIGN_IN);
}
}
};
//Initialize task list Array, ListView and Adapter.
final ArrayList<TaskList> taskLists = new ArrayList<TaskList>();
// Create an {@link TaskListAdapter}, whose data source is a list of {@link TaskList}s.
mTaskListAdapter = new TaskListAdapter(this, taskLists);
// Locate the {@link ListView} object in the view hierarchy of the {@link Activity}.
ListView listView = (ListView) findViewById(R.id.task_list_view);
//Set the empty view
mEmptyStateTextView = (TextView) findViewById(R.id.empty_view);
listView.setEmptyView(mEmptyStateTextView);
//Initialize the loading indicator
loadingIndicator = findViewById(R.id.loading_indicator);
loadingIndicator.setVisibility(View.INVISIBLE);
// Make the {@link ListView} use the {@link TaskListAdapter} defined above, so that the
// {@link ListView} will display list items for each {@link TaskList} in the list.
listView.setAdapter(mTaskListAdapter);
//Set and create the FAB and it's action listener
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Get add_list.xml view
LayoutInflater li = LayoutInflater.from(context);
View addTaskListView = li.inflate(R.layout.add_list, null);
//Create the prompt to enable the user to create a new task list
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
context);
// Set add_list.xml as the layout for alertdialog builder
alertDialogBuilder.setView(addTaskListView);
//Set the user input box
final EditText userInput = (EditText) addTaskListView
.findViewById(R.id.edit_list_name);
// Set dialog message
alertDialogBuilder
.setCancelable(false)
.setPositiveButton("Create",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
// Get list title from user and create a new task list
//Also fetch the FireBase ID and connect it to the new task list.
String mTaskListId = mTaskListDatabaseReference.push().getKey();
TaskList taskList = new TaskList(userInput.getText().toString(),mTaskListId);
mTaskListDatabaseReference.child(mTaskListId).setValue(taskList);
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int id) {
dialog.cancel();
}
});
// Create the dialog
AlertDialog alertDialog = alertDialogBuilder.create();
// Show the dialog
alertDialog.show();
}
});
// Set an item click listener on the ListView, which creates an intent to open
//the relevant task list and show the tasks inside.
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
// Find the current task list that was clicked on
TaskList currentTaskList = mTaskListAdapter.getItem(position);
//get the current task list's ID
currentTaskListId=currentTaskList.getId();
// Create a new intent to view the tasks in the chosen list
Intent taskIntent = new Intent(MainActivity.this, TaskActivity.class);
// Send the intent to launch a new activity
startActivity(taskIntent);
}
});
listView.setLongClickable(true);
registerForContextMenu(listView);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == SIGN_IN) {
if (resultCode == RESULT_OK) {
// Sign-in succeeded, set up the UI
Toast.makeText(this, "Signed in!", Toast.LENGTH_SHORT).show();
} else if (resultCode == RESULT_CANCELED) {
// Sign in was canceled by the user, finish the activity
Toast.makeText(this, "Sign in canceled", Toast.LENGTH_SHORT).show();
finish();
}
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.mini_menu,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.sign_out:
AuthUI.getInstance().signOut(this);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
protected void onResume() {
super.onResume();
mFirebaseAuth.addAuthStateListener(mAuthStateListener);
}
@Override
protected void onPause() {
super.onPause();
if (mAuthStateListener != null) {
mFirebaseAuth.removeAuthStateListener(mAuthStateListener);
}
mTaskListAdapter.clear();
detachDatabaseReadListener();
}
private void onSignedInInitialize(final String userId) {
//Get reference for the task list for the logged in user and attach the database listener
mTaskListDatabaseReference=mFirebaseDatabase.getReference().child("users").child(userId);
loadingIndicator.setVisibility(View.VISIBLE);
attachDatabaseReadListener();
mEmptyStateTextView.setText("No task lists, add a new one!");
loadingIndicator.setVisibility(View.GONE);
}
private void onSignedOutCleanup() {
mTaskListAdapter.clear();
detachDatabaseReadListener();
}
private void attachDatabaseReadListener() {
if (mChildEventListener == null) {
mChildEventListener = new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
TaskList taskList = dataSnapshot.getValue(TaskList.class);
mTaskListAdapter.add(taskList);
}
public void onChildChanged(DataSnapshot dataSnapshot, String s) {}
public void onChildRemoved(DataSnapshot dataSnapshot) {}
public void onChildMoved(DataSnapshot dataSnapshot, String s) {}
public void onCancelled(DatabaseError databaseError) {}
};
}
mTaskListDatabaseReference.addChildEventListener(mChildEventListener);
}
private void detachDatabaseReadListener() {
if (mChildEventListener != null) {
mTaskListDatabaseReference.removeEventListener(mChildEventListener);
mChildEventListener = null;
}
}
public static String getCurrentTaskListId() {
return currentTaskListId;
}
public static String getCurrentUserId() {
return currentUserId;
}
/**
* MENU
*/
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo){
if (v.getId() == R.id.task_list_view){
AdapterView.AdapterContextMenuInfo info =(AdapterView.AdapterContextMenuInfo)menuInfo;
menu.add(0,0,0,"Delete");
}
}
@Override
public boolean onContextItemSelected(MenuItem menuItem){
AdapterView.AdapterContextMenuInfo info=(AdapterView.AdapterContextMenuInfo)menuItem.getMenuInfo();
TaskList taskListClicked=mTaskListAdapter.getItem(info.position);
Log.d("check","" +taskListClicked.getTitle());
switch (menuItem.getItemId()) {
case 0:
mTaskListDatabaseReference.child(taskListClicked.getId()).removeValue();
mTaskListAdapter.remove(taskListClicked);
Toast.makeText(this, "Task List deleted!", Toast.LENGTH_LONG).show();
break;
default:
break;
}
return true;
}
任务 Activity 代码:
public class TaskActivity extends AppCompatActivity {
final Context context = this;
private TaskAdapter mTaskAdapter;
private int taskCount;
// TextView that is displayed when the list is empty //
private TextView mEmptyStateTextView;
//The loading indicator //
private View loadingIndicator;
//Edit text and button for creating new tasks quickly
private EditText mTaskEditText;
private Button mTaskCreateButton;
// Firebase instance variables
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mTaskDatabaseReference;
private DatabaseReference mTaskNumDatabaseReference;
private ChildEventListener mChildEventListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set the content of the activity to use the activity_main.xml layout file - the task lists
setContentView(R.layout.task_activity);
//Set up to allow Up navigation to parent activity
this.getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// Initialize Firebase components
mFirebaseDatabase = FirebaseDatabase.getInstance();
// Initialize references to views
mTaskEditText = (EditText) findViewById(R.id.task_edit_text);
mTaskCreateButton = (Button) findViewById(R.id.create_task_button);
// Enable Send button when there's text to send
mTaskEditText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
if (charSequence.toString().trim().length() > 0) {
mTaskCreateButton.setEnabled(true);
} else {
mTaskCreateButton.setEnabled(false);
}
}
@Override
public void afterTextChanged(Editable editable) {
}
});
// Create button creates a new task and clears the EditText
mTaskCreateButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Get task title from user and create a new task
//Also fetch the FireBase ID and connect it to the new task.
//And finally get the task's creation date
String creationDate ="Created: " + new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(new Date());
String taskId = mTaskDatabaseReference.push().getKey();
Task task = new Task(mTaskEditText.getText().toString(),false,taskId,creationDate);
mTaskDatabaseReference.child(taskId).setValue(task);
//add that task to the list's task count
mTaskNumDatabaseReference.child("taskNum").setValue(taskCount+1);
// Clear input box
mTaskEditText.setText("");
}
});
//Initialize task Array, ListView and Adapter.
final ArrayList<Task> tasks = new ArrayList<Task>();
// Create an {@link TaskAdapter}, whose data source is a list of {@link Task}s.
mTaskAdapter = new TaskAdapter(this, tasks);
// Locate the {@link ListView} object in the view hierarchy of the {@link Activity}.
ListView listView = (ListView) findViewById(R.id.task_list_view);
//Set the empty view
mEmptyStateTextView = (TextView) findViewById(R.id.empty_view);
listView.setEmptyView(mEmptyStateTextView);
//Initialize the loading indicator
loadingIndicator = findViewById(R.id.loading_indicator);
loadingIndicator.setVisibility(View.INVISIBLE);
// Make the {@link ListView} use the {@link TaskAdapter} defined above, so that the
// {@link ListView} will display list items for each {@link Task} in the list.
listView.setAdapter(mTaskAdapter);
//Set a regular click - opening the TaskInfoFragment
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
// Find the current task list that was clicked on
Log.d("clicked here bro","clicikcckckc");
Task currentTask = mTaskAdapter.getItem(position);
//Open the TaskInfoFragment for this task
TaskInfoFragment taskInfo = new TaskInfoFragment();
taskInfo.setCurrentTask(currentTask);
android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.frag_container, taskInfo);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
});
//Set context menu for ListView
listView.setLongClickable(true);
registerForContextMenu(listView);
//Get reference for the task list for the logged in user and attach the database listener
mTaskDatabaseReference=mFirebaseDatabase.getReference().child("users")
.child(MainActivity.getCurrentUserId())
.child(MainActivity.getCurrentTaskListId()).child("tasks");
mTaskNumDatabaseReference=mFirebaseDatabase.getReference().child("users")
.child(MainActivity.getCurrentUserId())
.child(MainActivity.getCurrentTaskListId());
//add listener to get the current task count in this specific task list
mTaskNumDatabaseReference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
TaskList taskList = dataSnapshot.getValue(TaskList.class);
taskCount=taskList.getTaskNum();
Log.d("post count: ", "" + taskCount);
}
@Override
public void onCancelled(DatabaseError databaseError) {
System.out.println("The read failed: " + databaseError.getCode());
}
});
}
@Override
protected void onResume() {
super.onResume();
loadingIndicator.setVisibility(View.VISIBLE);
attachDatabaseReadListener();
mEmptyStateTextView.setText("No tasks, add a new one!");
loadingIndicator.setVisibility(View.GONE);
}
@Override
protected void onPause() {
super.onPause();
mTaskAdapter.clear();
detachDatabaseReadListener();
}
private void attachDatabaseReadListener() {
if (mChildEventListener == null) {
mChildEventListener = new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Task task = dataSnapshot.getValue(Task.class);
mTaskAdapter.add(task);
}
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
//Task task = dataSnapshot.getValue(Task.class);
//mTaskAdapter.add(task);
}
public void onChildRemoved(DataSnapshot dataSnapshot) {
mTaskNumDatabaseReference.child("taskNum").setValue(taskCount-1);
}
public void onChildMoved(DataSnapshot dataSnapshot, String s) {}
public void onCancelled(DatabaseError databaseError) {}
};
}
mTaskDatabaseReference.addChildEventListener(mChildEventListener);
}
private void detachDatabaseReadListener() {
if (mChildEventListener != null) {
mTaskDatabaseReference.removeEventListener(mChildEventListener);
mChildEventListener = null;
}
}
/**
* MENU
*/
@Override
public void onCreateContextMenu(ContextMenu menu,View v, ContextMenu.ContextMenuInfo menuInfo){
if (v.getId() == R.id.task_list_view){
AdapterView.AdapterContextMenuInfo info =(AdapterView.AdapterContextMenuInfo)menuInfo;
menu.add(0,0,0,"Delete");
menu.add(0,1,1,"info");
}
}
@Override
public boolean onContextItemSelected(MenuItem menuItem){
AdapterView.AdapterContextMenuInfo info=(AdapterView.AdapterContextMenuInfo)menuItem.getMenuInfo();
Task taskClicked=mTaskAdapter.getItem(info.position);
Log.d("check","" +taskClicked.getTitle());
switch (menuItem.getItemId()) {
case 0:
mTaskDatabaseReference.child(taskClicked.getId()).removeValue();
mTaskAdapter.remove(taskClicked);
Toast.makeText(this, "Task deleted!", Toast.LENGTH_LONG).show();
break;
case 1:
//Open the TaskInfoFragment for this task
TaskInfoFragment taskInfo = new TaskInfoFragment();
taskInfo.setCurrentTask(taskClicked);
android.support.v4.app.FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.frag_container, taskInfo);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
break;
default:
break;
}
return true;
}
//set up the back button - to navigate to the parent activity
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
//Check if the call came from the TaskInfoFragment or the activity
Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.frag_container);
if(currentFragment!=null && currentFragment.isVisible()){
this.onBackPressed();
}
else{
NavUtils.navigateUpFromSameTask(this);
}
return true;
}
return super.onOptionsItemSelected(item);
}
TaskAdapter - TaskActivity 适配器
package com.example.guyerez.todotiger;
import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.TextView;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import java.util.ArrayList;
import java.util.Locale;
/**
* {@link TaskAdapter} is an {@link ArrayAdapter} that can provide the layout for each task item
* based on a data source, which is a list of {@link Task} objects.
*/
public class TaskAdapter extends ArrayAdapter<Task> {
//Define FireBase instance variables
private DatabaseReference mTaskDatabaseReference;
private FirebaseDatabase mFirebaseDatabase;
/**
* Create a new {@link TaskAdapter} object.
*
* @param context is the current context (i.e. Activity) that the adapter is being created in.
* @param tasks is the list of {@link Task}s to be displayed.
*/
public TaskAdapter(Context context, ArrayList<Task> tasks) {
super(context, 0, tasks);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Check if an existing view is being reused, otherwise inflate the view
View listItemView = convertView;
if (listItemView == null) {
listItemView = LayoutInflater.from(getContext()).inflate(
R.layout.task_item, parent, false);
}
// Get the {@link Task} object located at this position in the list
final Task currentTask = getItem(position);
// Locate the TextView in the task_item.xml layout with the ID task_title.
final TextView titleTextView = (TextView) listItemView.findViewById(R.id.task_title);
// Get the task's title from the currentTask object and set it in the text view
titleTextView.setText(currentTask.getTitle());
//If the task is completed - title Strikethrough
titleTextView.setBackgroundResource(strikeCompleted(currentTask.getCompleted()));
//Initialize the check box and check it if the task was completed.
CheckBox checkBox = (CheckBox) listItemView.findViewById(R.id.check_box);
checkBox.setOnCheckedChangeListener(null);
checkBox.setChecked(currentTask.getCompleted());
//Initialize the creation date TextView in the task_item.xml layout with the ID creation_date
TextView creationDateTextView = (TextView) listItemView.findViewById(R.id.creation_date);
//Get the task's creation date from the currentTask object and set it in the text view
creationDateTextView.setText(currentTask.getCreationDate());
// Initialize Firebase DB
mFirebaseDatabase = FirebaseDatabase.getInstance();
//Get the task DB reference to edit task completion status
// Find the CheckBox in the task_item.xml layout with the ID check_box.
checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
mTaskDatabaseReference=mFirebaseDatabase.getReference()
.child("users").child(MainActivity.getCurrentUserId())
.child(MainActivity.getCurrentTaskListId()).child("tasks").child(currentTask.getId());
if (isChecked) {
titleTextView.setBackgroundResource(R.drawable.strike_through);
mTaskDatabaseReference.child("completed").setValue(true);
} else {
titleTextView.setBackgroundResource(0);
mTaskDatabaseReference.child("completed").setValue(false);
}
}
}
);
// Return the whole list item layout (containing 1 text view and 1 checkbox) so that it can be shown in the ListView.
return listItemView;
}
private int strikeCompleted(boolean completed){
if (completed){
return R.drawable.strike_through;
}
else{
return 0;
}
}
最佳答案
在为包含 CheckBox 的 ListView 行尝试了几种推荐的解决方法(如 here )但没有成功之后，我想建议一种不同的方法:
使用另一个透明的 View，它覆盖整行，CheckBox 周围的一小块区域除外。让这个 View 有一个 OnClickListener 触发 TaskInfoFragment 的打开。
理想情况下，我们会使用一个接口(interface)，这样 TaskAdapter 就可以将点击的 Task 传递给 TaskActivity，后者又会显示 fragment 。
几个小时后......(@Guy，你的提示“尝试删除所有与复选框相关的代码和 xml，并且常规点击问题仍然存在”让我一个接一个地交换组件，直到我将它缩小到行xml) 我找到了 TaskActivity 中 ListView 的 OnItemClickListener 不触发的原因。 Task 列表的根 ConstraintLayout 有一个 TaskList 列表的根没有的属性:android:longClickable="真”
删除此属性会使 ListView 正常运行。
关于android - Listview OnItemClickListener 在 MainActivity 上工作但不在类似的 TaskActivity 上工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52431329/