java - fragment 与传承

Question

我正在尝试使用我正在创建的不同 fragment 来更改主要 Activity 的框架 View 。

我的onNavigationItemSelected:

import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.media.Image;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.util.Base64;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.TextView;

public boolean onNavigationItemSelected(MenuItem item) {
    Fragment fragment;
    FragmentManager fragmentManager = getFragmentManager();

    int id = item.getItemId();

    if (id == R.id.nav_camara) {
        // Handle the camera action
    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {
         fragment  = new FragmentOne();

    } else if (id == R.id.nav_manage) {
         fragment = new FragmentTwo();
    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

我的 fragment 是:

package com.example.tombushmits.pilot;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.tombushmits.pilot.R;

public class FragmentOne extends Fragment {

    public FragmentOne(){}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup         container,
                             Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment1, container, false);
    }
}


package com.example.tombushmits.pilot;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.tombushmits.pilot.R;

public class FragmentTwo extends Fragment {

public FragmentTwo(){}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment2, container, false);
}
}

但我收到错误:

Error:(116, 26) error: incompatible types required: Fragment found:
FragmentOne

Answer 1

您的FragmentOne扩展了android.support.v4.app.Fragment。在 MainActivity 中，您使用 getFragmentManager()，它与 android.app.Fragment 类一起使用。您应该让 FragmentOne 继承 android.app.Fragment，或者在 MainActivity 中使用 getSupportFragmentManager()。