치명적인 예외 : 주요 java.lang.NullPointerException이

-1

나는치명적인 예외 : 주요 java.lang.NullPointerException이

내가 사전 응용 프로그램을 시도하고 아주 잘 프로그래밍에 대해 알고하지 않는 안돼서, 나는

01-27 06:27:57.561: E/AndroidRuntime(2439): FATAL EXCEPTION: main 
01-27 06:27:57.561: E/AndroidRuntime(2439): Process: taejung.kim.dic, PID: 2439 
    01-27 06:27:57.561: E/AndroidRuntime(2439): java.lang.RuntimeException: Unable to start activity 
    ComponentInfo{taejung.kim.dic/taejung.kim.dic.DictionaryMainActivity}: java.lang.NullPointerException 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.ActivityThread.access$800(ActivityThread.java:135) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.os.Handler.dispatchMessage(Handler.java:102) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.os.Looper.loop(Looper.java:136) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.ActivityThread.main(ActivityThread.java:5017) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at java.lang.reflect.Method.invokeNative(Native Method) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at java.lang.reflect.Method.invoke(Method.java:515) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at dalvik.system.NativeStart.main(Native Method) 
01-27 06:27:57.561: E/AndroidRuntime(2439): Caused by: java.lang.NullPointerException 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at taejung.kim.dic.DictionaryMainActivity.onCreate(DictionaryMainActivity.java:45) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.Activity.performCreate(Activity.java:5231) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 
01-27 06:27:57.561: E/AndroidRuntime(2439):  ... 11 more

에 붙어 덕분입니다 DictionaryMainActivity.java

package taejung.kim.dic; 

import android.support.v7.app.ActionBarActivity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import java.util.ArrayList; 
import java.util.HashMap; 

import android.app.Activity; 
import android.os.Bundle; 
import android.text.Editable; 
import android.text.TextWatcher; 
import android.widget.ArrayAdapter; 
import android.widget.EditText; 
import android.widget.ListView; 
`enter code here`public class DictionaryMainActivity extends ActionBarActivity { 

private ListView lv; 

    // Listview Adapter 
    ArrayAdapter<String> adapter; 

    // Search EditText 


    // ArrayList for Listview 
    ArrayList<HashMap<String, String>> productList; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_list_main); 

     // Listview Data 
     String products[] = {"Dell Inspiron", "HTC One X", "HTC Wildfire S", "HTC Sense", "HTC Sensation XE", 
           "iPhone 4S", "Samsung Galaxy Note 800", 
           "Samsung Galaxy S3", "MacBook Air", "Mac Mini", "MacBook Pro"}; 



     // Adding items to listview 
     adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, products); 
     lv.setAdapter(adapter); 
    } 

}

activity_list_main.xml

<LinearLayout 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:orientation="vertical" 
    tools:context="taejung.kim.dic.DictionaryMainActivity" > 


    <!-- 모음리스트 --> 

    <HorizontalScrollView 
     android:id="@+id/MoumScroll" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:fillViewport="true" > 

    <LinearLayout 
     android:id="@+id/MoumList" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:orientation="horizontal" > 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅏ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅑ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅓ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅕ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅗ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅛ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅜ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅠ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅡ" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="ㅣ" /> 
    </LinearLayout> 
    </HorizontalScrollView> 


    <!-- 자음리스트 --> 
    <HorizontalScrollView 
     android:id="@+id/JaumScroll" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:fillViewport="true"> 
    <LinearLayout 
     android:id="@+id/JaumList" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:orientation="horizontal" > 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ga" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/na" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/da" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ra" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ma" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ba" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/sa" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/aa" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ja" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/cha" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ka" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ta" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/pa" /> 

     <Button 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_weight="1" 
      android:text="@string/ha" /> 
    </LinearLayout> 
    </HorizontalScrollView> 

    <!--화면이동 --> 

    <LinearLayout 
     android:id="@+id/BtLayout1" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:orientation="horizontal" 
     android:layout_weight="8" > 

     <Button 
      android:id="@+id/BtHelp1" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="도움말" 
      android:layout_weight="1"/> 

     <Button 
      android:id="@+id/BtSearch1" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="검색" 
      android:layout_weight="1"/> 
    </LinearLayout> 

    <ListView 
     android:id="@+id/listview" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" /> 



    </LinearLayout>

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="taejung.kim.dic" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk 
    android:minSdkVersion="14" 
    android:targetSdkVersion="21" /> 

<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name=".DictionaryMainActivity" 

     android:label="@string/app_name" 
     android:windowSoftInputMode="stateHidden"> 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 


</application> 

</manifest>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical" > 

<!-- Single ListItem --> 

<!-- Product Name --> 
<TextView android:id="@+id/product_name" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:padding="10dip" 
    android:textSize="16dip" 
    android:textStyle="bold"/>  

</LinearLayout>

매니페스트 list_item.xml 나는 문제가 주요 활동의 한 OnCreate에 생각하지만, 무슨 문제가 이해가 안 수 있습니다.

출처

2015-01-27 Taejung Kim

오, 죄송합니다. –

lv 변수를 초기화하는 것을 잊었습니다.

lv = (ListView)findViewById(R.id.listview);

setContentView() 후 lv의 메소드를 호출하기 전에 추가합니다.

출처

2015-01-27 12:00:03 laalto

ListView lv는 초기화되지 않습니다. 그래서 당신은이 라인에서 NPE를 얻을 : 당신은 아직 생성 된 객체에 대한 lv.setAdapter(adapter);를 호출하려고 호출 있도록

lv.setAdapter(adapter);

출처

2015-01-27 12:01:04 Jens

당신의 ListView lv; 변수는 초기화되지 않습니다.

출처

2015-01-27 12:05:36

치명적인 예외 : 주요 java.lang.NullPointerException이

답변

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