如何在 NavigationDrawer 中使用谷歌地图？

Question

我对 Coding 比较陌生，但请多多包涵。我正在尝试将谷歌地图放在导航抽屉中。我认为最好的方法是使用片段，但尽管我进行了各种尝试，但我仍然收到此错误：“错误：(35, 62) 错误：不兼容的类型：MapsActivity 无法转换为片段”。

我有两个活动 1. MainActiyity：哪里有错误。 2. MapsActivity：在Android studio新建项目时选择创建google maps app时默认的Activity。

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
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.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;

import android.support.v4.app.FragmentActivity;


public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {    

NavigationView navigationView = null;
Toolbar toolbar = null;

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

    // Set to start with fragment
    MapsActivity fragment = new MapsActivity();
    android.support.v4.app.FragmentTransaction fragmentTransaction =
            getSupportFragmentManager().beginTransaction();
    fragmentTransaction.replace(R.id.fragment_container, fragment);
    fragmentTransaction.commit();


    toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_building) {
        MapsActivity fragment = new MapsActivity();
        android.support.v4.app.FragmentTransaction fragmentTransaction =
                getSupportFragmentManager().beginTransaction();
        fragmentTransaction.replace(R.id.fragment_container, fragment);
        fragmentTransaction.commit();

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

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

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

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

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

    }

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

另外，fragmentTransaction.replace(R.id.fragment_container, fragment); 中的“fragment”一词 红色下划线。 我试图找到不同的教程和指南，但没有解决我的问题。

Answer 1

您不能对 Activity 执行 FragmentTransaction。

为了在 NavigationDrawer 中使用 Google 地图，请使用扩展 SupportMapFragment 的片段，并添加您的 MapsActivity 类当前具有的所有功能。

用这个开头：

public class MapsFragment extends SupportMapFragment
        implements OnMapReadyCallback {

    GoogleMap mGoogleMap;

    @Override
    public void onResume() {
        super.onResume();

        setUpMapIfNeeded();
    }

    private void setUpMapIfNeeded() {

        if (mGoogleMap == null) {
            getMapAsync(this);
        }
    }

    @Override
    public void onMapReady(GoogleMap googleMap)
    {
        mGoogleMap=googleMap;
        mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
    }

}

然后在 Activity 中，将其更改为使用 Fragment：

// Set to start with fragment
MapsFragment fragment = new MapsFragment();
android.support.v4.app.FragmentTransaction fragmentTransaction =
        getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();