我遇到了setSupportActionBar的问题 我使用extend activity和setSupportActionBar的活动需要AppCompatActivity，
但是当我将活动扩展到appcompatactivity时，我的应用程序很快停止了：
此处代码和日志
MainList.java
package com.felix.tgp;
/**
* Created by Felix on 4/15/2016.
*/
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
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.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.JsonArrayRequest;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class MainList extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
// Log tag
private static final String TAG = MainList.class.getSimpleName();
// Movies json url
private static final String url = "http://....";
private ProgressDialog pDialog;
private List<Movie> movieList = new ArrayList<Movie>();
private ListView listView;
private CustomListAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
listView = (ListView) findViewById(R.id.list);
adapter = new CustomListAdapter(this, movieList);
listView.setAdapter(adapter);
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 = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
/*
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapter, View v, int position) {
ItemClicked item = adapter.getItemAtPosition(position);
Intent intent = new Intent(MainList.this, destinationActivity.class);
//based on item add info to intent
startActivity(intent);
}
});*/
pDialog = new ProgressDialog(this);
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
// Creating volley request obj
JsonArrayRequest movieReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Movie movie = new Movie();
movie.setTitle(obj.getString("name"));
movie.setThumbnailUrl(obj.getString("images1"));
//movie.setDescribe(obj.getString("describe"));
//movie.setRating(((Number) obj.get("rating"))
// .doubleValue());
movie.setYear(obj.getInt("id"));
movie.setTipe(obj.getString("tipe"));
/*// Genre is json array
JSONArray genreArry = obj.getJSONArray("genre");
ArrayList<String> genre = new ArrayList<String>();
for (int j = 0; j < genreArry.length(); j++) {
genre.add((String) genreArry.get(j));
}
movie.setGenre(genre);*/
// adding movie to movies array
movieList.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(movieReq);
}
@Override
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
@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 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 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
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_calculator) {
// Handle the camera action
Intent calculator = new Intent(MainList.this, Calculator.class);
startActivity(calculator);
} else if (id == R.id.nav_chest) {
Intent List = new Intent(MainList.this, MainList.class);
startActivity(List);
} else if (id == R.id.nav_back) {
} else if (id == R.id.nav_shoulder) {
} else if (id == R.id.nav_arm) {
} else if (id == R.id.nav_abdominal) {
} else if (id == R.id.nav_leg) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
}
Activity_list.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainList" >
<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="@color/list_divider"
android:dividerHeight="1dp"
android:listSelector="@drawable/list_row_selector" />
</RelativeLayout>
listrow.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/list_row_selector"
android:padding="8dp" >
<!-- Thumbnail Image -->
<com.android.volley.toolbox.NetworkImageView
android:id="@+id/thumbnail"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_alignParentLeft="true"
android:layout_marginRight="8dp" />
<!-- Movie Title -->
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/thumbnail"
android:layout_toRightOf="@+id/thumbnail"
android:textSize="@dimen/title"
android:textStyle="bold" />
<!-- Rating -->
<TextView
android:id="@+id/describe"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/title"
android:layout_marginTop="1dip"
android:layout_toRightOf="@+id/thumbnail"
android:textSize="@dimen/rating" />
<!-- Genre -->
<TextView
android:id="@+id/tipe"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/describe"
android:layout_marginTop="5dp"
android:layout_toRightOf="@+id/thumbnail"
android:textColor="@color/genre"
android:textSize="@dimen/genre" />
<!-- Release Year -->
<TextView
android:id="@+id/releaseYear"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:textColor="@color/year"
android:textSize="@dimen/year" />
</RelativeLayout>
style.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">#FF39A3EB</item>
<item name="colorPrimaryDark">#FF185896</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
<style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
<style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
</resources>
的Manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.felix.tgp" >
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_icon"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme"
android:name="com.felix.tgp.AppController">
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Calculator"
android:label="Body Mass Index Calculator"
android:theme="@style/AppTheme.NoActionBar"
android:screenOrientation="portrait">
</activity>
<activity
android:name="com.felix.tgp.MainList"
android:label="Chest Workout"
android:theme="@style/AppTheme.NoActionBar"
android:screenOrientation="portrait">
</activity>
</application>
</manifest>
日志
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: FATAL EXCEPTION: main
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: Process: com.felix.tgp, PID: 32173
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.felix.tgp/com.felix.tgp.MainList}: java.lang.NullPointerException
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.os.Looper.loop(Looper.java:136)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5017)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:515)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: Caused by: java.lang.NullPointerException
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:100)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:93)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.support.v7.internal.app.ToolbarActionBar.<init>(ToolbarActionBar.java:78)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:206)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:99)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at com.felix.tgp.MainList.onCreate(MainList.java:51)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:5231)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.access$800(ActivityThread.java:135)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.os.Looper.loop(Looper.java:136)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5017)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:515)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
04-20 13:46:31.174 32173-32173/com.felix.tgp E/AndroidRuntime: at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
您尚未在Toolbar布局xml文件中定义Activity窗口小部件。你必须添加这样的东西才能摆脱NullPointerException。
<android.support.design.widget.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="@dimen/app_bar_height"
android:background="@color/transparent"
android:theme="@style/AppTheme.AppBarOverlay"
app:elevation="0dp">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="55dp"
android:layout_marginTop="@dimen/app_bar_height"
android:background="@color/transparent"
app:popupTheme="@style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
但这不会是你问题的结束。我看到您的代码正在寻找drawer layouts以及xml中未定义的其他内容 ......您也必须解决这个问题。