incompatible types: HomeFragment cannot be convert

问题:

I'm getting an error in this part of code:

private void displayView(int position) {
    // update the main content by replacing fragments
    Fragment fragment = null;
    switch (position) {
        case 0:
            fragment = new HomeFragment();
            break;
        case 1:
            fragment =new FindPeopleFragment();
            break;
        case 2:
            fragment = new PhotosFragment();
            break;
        case 3:
            fragment = new CommunityFragment();
            break;
        case 4:
            fragment = new PagesFragment();
            break;
        case 5:
            fragment = new WhatsHotFragment();
            break;

        default:
            break;
    }

    if (fragment != null) {
        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.frame_container, fragment).commit();

        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        mDrawerList.setSelection(position);
        setTitle(navMenuTitles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
    } else {
        // error in creating fragment
        Log.e("MainActivity", "Error in creating fragment");
    }
}

I get

error: incompatible types: HomeFragment cannot be converted to Fragment

this is the imports:

package liorsiag.lgbt;
import android.app.FragmentManager;
import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.widget.DrawerLayout;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import java.util.ArrayList;

and this is the class title:

public class MainActivity extends FragmentActivity {
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

No matter what I've tried I still get this error

I've tried a lot of navigation drawer tutorials, but none of them seem to work.

回答1:

This seems to be an import problem.

When using getFragmentMangager(), make sure that your Fragment classes extend android.app.Fragment class.

If by any chance you are using android.support.v4.app.Fragment (see your imports), then you need to use getSupportFragmentManager() instead

Hope it helps

回答2:

Try changing

import android.app.Fragment;

to

import android.support.v4.app.Fragment;

Use classes from that support lib for all other imports too. Also getSupportFragmentManager() as mentioned in the other answer.

回答3:

In your HomeFragment class

replace:

import android.app.Fragment;

with:

import android.support.v4.app.Fragment;

回答4:

In my case i have changed line-1 with line-2

Line-1: import android.app.Fragment;

Line-2: import android.support.v4.app.Fragment;

Its working

回答5:

use getSupportFragmentManager() Instead of getFragmentManager()

getSupportFragmentManager()
    .beginTransaction()
    .replace(in.jama.app.R.id.container, new Fragment())
    .commit();

回答6:

you just have to import android.support.v4.app.Fragment; in the all the FragmentClass();. that's it.

回答7:

import android.app.Fragment; works with getFragmentManager() method but before you have to remove the import android.support.v4.app.Fragment;

回答8:

In Android Studio 2.3 getSupportFragmentManager works with android.support.v4.app but android studio 3.1 you have to use getFragmentManager enter image description here

回答9:

If you are using support library, you should ensure to import both Fragment and FragmentManager from the support library. You will also need to ensure to load the support fragment manager.

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
//other imports here...

public class SomeActivity extends AppCompatActivity {

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

        FragmentManager fm = getSupportFragmentManager();
        Fragment fragment = fm.findFragmentById(R.id.fragment_container);

        if(fragment == null) {
            fragment = new SomeFragment();
            fm.beginTransaction().add(R.id.fragment_container, fragment).commit();
        }

    }
}