我正在使用这个Android应用程序。在这个应用程序中，“StartingActivity.java”自动变为“HomeActivity.java”，其中包含导航抽屉。但在更改活动时，应用程序崩溃。请帮助.. 这是代码
StartingActivity.java
package com.example.abhi.mymanager;
import android.content.Intent;
import android.os.Handler;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class StartingActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_starting);
// for sending it to another activity after a time
Handler handler=new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
Intent i=new Intent(StartingActivity.this,HomeActivity.class);
startActivity(i);
}
}
},5000);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_starting, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
HomeActivity.java
package com.example.abhi.mymanager;
import android.os.Bundle;
import android.os.PersistableBundle;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
/**
* Created by abhi on 29-01-2015.
*/
public class HomeActivity extends ActionBarActivity implements AdapterView.OnItemClickListener {
private DrawerLayout drawerLayout;
private ListView listView;
private String[] options;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home_layout);
drawerLayout=(DrawerLayout)findViewById(R.id.drawer_layout);
listView=(ListView)findViewById(R.id.left_drawer);
listView.setAdapter(new ArrayAdapter<> (this,android.R.layout.simple_list_item_1,options));
listView.setOnItemClickListener(this);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(this,options[position],Toast.LENGTH_LONG).show();
getSupportActionBar().setTitle(options[position]);
}
}
activity_starting.xml
<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" android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".StartingActivity"
android:background="#ffb6a6ff">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="My Manager"
android:id="@+id/textView"
android:layout_marginTop="65dp"
android:textSize="@dimen/abc_action_bar_default_height_material"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:textColor="#ff2312ff" />
</RelativeLayout>
home_layout.xml
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- the main content view-->
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<!-- the navigation drawer-->
<ListView
android:id="@+id/left_drawer"
android:entries="@array/Options"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
android:background="@android:color/holo_purple"
/>
</android.support.v4.widget.DrawerLayout>
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.abhi.mymanager" >
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".StartingActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".HomeActivity"
android:label="@string/app_name"
>
</activity>
</application>
</manifest>
的strings.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">My Manager</string>
<string name="hello_world">Hello world!</string>
<string name="action_settings">Settings</string>
<string-array name="Options">
<item name="MyBoard">My Board</item>
<item name="CreateBoard">Create Board</item>
</string-array>
</resources>
logcat的
02-01 17:23:55.811 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:23:56.171 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.view.ViewGroup.onNestedScrollAccepted, referenced from method android.support.v7.internal.widget.ActionBarOverlayLayout.onNestedScrollAccepted
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 11346: Landroid/view /ViewGroup;.onNestedScrollAccepted (Landroid/view/View;Landroid/view/View;I)V
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6f at 0x0000
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.view.ViewGroup.onStopNestedScroll, referenced from method android.support.v7.internal.widget.ActionBarOverlayLayout.onStopNestedScroll
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 11352: Landroid/view/ViewGroup;.onStopNestedScroll (Landroid/view/View;)V
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6f at 0x0000
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.view.ViewGroup.onWindowSystemUiVisibilityChanged, referenced from method android.support.v7.internal.widget.ActionBarOverlayLayout.onWindowSystemUiVisibilityChanged
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 11354: Landroid/view/ViewGroup;.onWindowSystemUiVisibilityChanged (I)V
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6f at 0x0008
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.support.v7.internal.widget.ActionBarOverlayLayout.stopNestedScroll, referenced from method android.support.v7.internal.widget.ActionBarOverlayLayout.setHideOnContentScrollEnabled
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 9040: Landroid/support/v7/internal/widget/ActionBarOverlayLayout;.stopNestedScroll ()V
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x000e
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.view.ViewGroup.onRtlPropertiesChanged, referenced from method android.support.v7.widget.Toolbar.onRtlPropertiesChanged
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 11349: Landroid/view/ViewGroup;.onRtlPropertiesChanged (I)V
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6f at 0x0007
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getChangingConfigurations, referenced from method android.support.v7.internal.widget.TintTypedArray.getChangingConfigurations
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 365: Landroid/content/res/TypedArray;.getChangingConfigurations ()I
02-01 17:23:56.181 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0002
02-01 17:23:56.191 13075-13075/com.example.abhi.mymanager I/dalvikvm﹕ Could not find method android.content.res.TypedArray.getType, referenced from method android.support.v7.internal.widget.TintTypedArray.getType
02-01 17:23:56.191 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ VFY: unable to resolve virtual method 387: Landroid/content/res/TypedArray;.getType (I)I
02-01 17:23:56.191 13075-13075/com.example.abhi.mymanager D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0002
02-01 17:23:58.851 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:23:59.561 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:23:59.911 13075-13075/com.example.abhi.mymanager I/PGA﹕ New SOCKET connection: .abhi.mymanager (pid 13075, tid 13075)
02-01 17:24:00.081 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:24:01.661 13075-13075/com.example.abhi.mymanager D/AndroidRuntime﹕ Shutting down VM
02-01 17:24:01.661 13075-13075/com.example.abhi.mymanager W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb2c9e180)
02-01 17:24:01.661 13075-13075/com.example.abhi.mymanager D/AndroidRuntime﹕ procName from cmdline: com.example.abhi.mymanager
02-01 17:24:01.661 13075-13075/com.example.abhi.mymanager E/AndroidRuntime﹕ in writeCrashedAppName, pkgName :com.example.abhi.mymanager
02-01 17:24:01.671 13075-13075/com.example.abhi.mymanager D/AndroidRuntime﹕ file written successfully with content: com.example.abhi.mymanager StringBuffer : ;com.example.abhi.mymanager
02-01 17:24:01.681 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:24:02.081 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:24:02.531 13075-13082/com.example.abhi.mymanager I/jdwp﹕ Ignoring second debugger -- accepting and dropping
02-01 17:24:03.021 13075-13075/com.example.abhi.mymanager I/Process﹕ Sending signal. PID: 13075 SIG: 9
02-01 17:24:03.021 13075-13075/com.example.abhi.mymanager E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.abhi.mymanager/com.example.abhi.mymanager.HomeActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
Caused by: java.lang.NullPointerException
at java.util.Arrays$ArrayList.<init>(Arrays.java:38)
at java.util.Arrays.asList(Arrays.java:154)
at android.widget.ArrayAdapter.<init>(ArrayAdapter.java:128)
at com.example.abhi.mymanager.HomeActivity.onCreate(HomeActivity.java:28)
at android.app.Activity.performCreate(Activity.java:4465)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1051)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:825)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:592)
at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
您的options数组未初始化。您无法将null作为数组传递给ArrayAdapter。