This question already has an answer here:
- Explanation of “ClassCastException” in Java 11 answers
Here is my problem. Below is my class (Events.java) below it is the error. I continue to run my code on my phone but continue to get that error. I don't know what exactly the problem is and I don't know how to fix it. I tried everything I looked up but kept getting errors. Please help I'm a noob obviously.
package com.androidapp.restart;
import android.app.Fragment;
import android.app.LoaderManager;
import android.app.ProgressDialog;
import android.content.ContentUris;
import android.content.CursorLoader;
import android.content.Intent;
import android.content.Loader;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import com.getbase.floatingactionbutton.FloatingActionButton;
/**
* Created by aa215995 on 3/2/2018.
*/
public class Events extends Fragment implements LoaderManager.LoaderCallbacks<Cursor> {
private FloatingActionButton mAddEventButton;
private Toolbar mToolbar;
EventCursorAdapter mCursorAdapter;
EventDbHelper eventDbHelper = new EventDbHelper(getActivity());
ListView eventListView;
ProgressDialog prgDialog;
private static final int VEHICLE_LOADER = 0;
@Nullable
@Override
public ListView onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
eventListView = (ListView) inflater.inflate(R.layout.nav_events, container, false);
mToolbar = (Toolbar) getView().findViewById(R.id.toolbar);
((AppCompatActivity)getActivity()).setSupportActionBar(mToolbar);
mToolbar.setTitle("Events");
eventListView = (ListView) getView().findViewById(R.id.list);
View emptyView = getView().findViewById(R.id.empty_view);
eventListView.setEmptyView(emptyView);
mCursorAdapter = new EventCursorAdapter(getActivity(), null);
eventListView.setAdapter(mCursorAdapter);
eventListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
Intent intent = new Intent(view.getContext(), AddEvent.class);
Uri currentVehicleUri = ContentUris.withAppendedId(EventContract.EventEntry.CONTENT_URI, id);
// Set the URI on the data field of the intent
intent.setData(currentVehicleUri);
startActivity(intent);
}
});
mAddEventButton = (FloatingActionButton) getView().findViewById(R.id.fab);
mAddEventButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), AddEvent.class);
startActivity(intent);
}
});
getLoaderManager().initLoader(VEHICLE_LOADER, null, this);
return eventListView;
}
@Override
public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
String[] projection = {
EventContract.EventEntry._ID,
EventContract.EventEntry.KEY_TITLE,
EventContract.EventEntry.KEY_DATE,
EventContract.EventEntry.KEY_TIME,
EventContract.EventEntry.KEY_REPEAT,
EventContract.EventEntry.KEY_REPEAT_NO,
EventContract.EventEntry.KEY_REPEAT_TYPE,
EventContract.EventEntry.KEY_ACTIVE
};
return new CursorLoader(getActivity(), // Parent activity context
EventContract.EventEntry.CONTENT_URI, // Provider content URI to query
projection, // Columns to include in the resulting Cursor
null, // No selection clause
null, // No selection arguments
null); // Default sort order
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
mCursorAdapter.swapCursor(cursor);
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
mCursorAdapter.swapCursor(null);
}
}
This is the error
05-24 14:02:00.885 15627-15627/com.androidapp.restart E/AndroidRuntime:
FATAL EXCEPTION: main
Process: com.androidapp.restart, PID: 15627
java.lang.ClassCastException: android.widget.LinearLayout cannot be cast
to android.widget.ListView
at com.androidapp.restart.Events.onCreateView(Events.java:47)
at com.androidapp.restart.Events.onCreateView(Events.java:31)
at android.app.Fragment.performCreateView(Fragment.java:2508)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1279)
at android.app.FragmentManagerImpl.addAddedFragments(FragmentManager.java:2407)
at android.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2186)
at android.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2142)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2043)
at android.app.FragmentManagerImpl$1.run(FragmentManager.java:719)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
This is the xml file (events.xml)
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.androidapp.restart.Events">
<ListView
android:id="@+id/list"
android:layout_below="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<RelativeLayout
android:id="@+id/empty_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true">
<TextView
android:id="@+id/no_event_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:padding="16dp"
android:gravity="center"
android:text="@string/no_cardetails"/>
</RelativeLayout>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_margin="16dp"
android:src="@drawable/ic_add_black_24dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent" />
EDITED
Now I have change the xml to a Relative Layout, same issues, but here is another issue I found:
at android.app.Fragment.performCreateView(Fragment.java:2508)
Here is the section of the Fragment.java:
if (mFragmentManager != null) {
writer.print(prefix); writer.print("mFragmentManager=");
writer.println(mFragmentManager);
}
This is an issue:
eventListView = (ListView) inflater.inflate(R.layout.nav_events, container, false);
You try to inflate listview but inflater returns you a LinearLayout a parent of all views. You need inflate the LinearLayout instead of listview and this is causes to cast exception.
You are trying to cast a layout on a listview
add this @id into your LinearLayout and inflate it in your Activity
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@id/layout";
tools:context="com.delaroystudiuos.alarmreminder.MainActivity">
and then call it like this
LinearLayout ll = (LinearLayout) inflater.inflate(R.layout.layout, container, false);;
If you are trying to access your existing ListView item in the XML:
<ListView
android:id="@+id/list"
android:layout_below="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
You will need to instead use:
View view = inflater.inflate(R.layout.nav_events, container, false);
eventListView = view.findViewById(R.id.list);
来源：https://stackoverflow.com/questions/50516897/im-having-problems-with-running-the-code-on-my-device