ListView自定义适配器XML Inflater空指针异常

Question

我试图得到一个自定义适配器使用XML Inflater，虽然我得到一个NullPointerException。

这里是类：

public class ListView_Start_Quran_Adapter2 extends BaseAdapter { 
private String[]   SuraNames; 
private int[]    PageNumber; 
Context      mContext; 
private LayoutInflater mInflater; 

public ListView_Start_Quran_Adapter2(Context context, String[] SuraNames, int[] PageNumber) { 
    mContext  = context; 
    this.SuraNames = SuraNames; 
    this.PageNumber = PageNumber; 
} 

@Override 
public int getCount() { 
    return SuraNames.length; 
} 

@Override 
public Object getItem(int arg0) { 
    return SuraNames[arg0]; 
} 

@Override 
public long getItemId(int arg0) { 
    return PageNumber[arg0]; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    ViewHolder  holder; 

    if(convertView == null) { 
     convertView = mInflater.inflate(R.layout.start_row, parent,false); //line 47 
     holder=new ViewHolder(); 

     holder.tv_SuraName =(TextView)convertView.findViewById(R.id.Start_Name); 
     holder.tv_PageNumber = (TextView)convertView.findViewById(R.id.Start_Numbering); 
     convertView.setTag(holder); 
    } else { 
     holder = (ViewHolder) convertView.getTag(); 
    } 

    holder.tv_SuraName.setText(SuraNames[position]); 
    holder.tv_PageNumber.setText(Integer.toString(PageNumber[position])); 

    return convertView; 
} 

class ViewHolder { 
    TextView  tv_SuraName; 
    TextView  tv_PageNumber; 
} 

}

的logcat：

07-10 20:56:31.643: ERROR/AndroidRuntime(1464): FATAL EXCEPTION: main 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464): java.lang.NullPointerException 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at omar.quran1.ListView_Start_Quran_Adapter2.getView(ListView_Start_Quran_Adapter2.java:47) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.AbsListView.obtainView(AbsListView.java:1560) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.ListView.measureHeightOfChildren(ListView.java:1265) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.ListView.onMeasure(ListView.java:1176) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:386) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:309) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.LinearLayout.measureVertical(LinearLayout.java:386) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.LinearLayout.onMeasure(LinearLayout.java:309) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.widget.FrameLayout.onMeasure(FrameLayout.java:250) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.View.measure(View.java:8366) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewRoot.performTraversals(ViewRoot.java:844) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1865) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.os.Handler.dispatchMessage(Handler.java:99) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.os.Looper.loop(Looper.java:130) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at android.app.ActivityThread.main(ActivityThread.java:3687) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at java.lang.reflect.Method.invokeNative(Native Method) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at java.lang.reflect.Method.invoke(Method.java:507) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600) 
07-10 20:56:31.643: ERROR/AndroidRuntime(1464):  at dalvik.system.NativeStart.main(Native Method) 

start_row.xml：

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:id="@+id/relativeLayout1" android:layout_height="wrap_content"> 
    <TextView 
    android:layout_alignParentLeft="true" 
    android:id="@+id/Start_Numbering"   
    android:textSize="19.5sp"    
    android:layout_width="wrap_content"   
    android:layout_height="wrap_content" 
    android:layout_gravity="center_vertical"/> 
    <TextView 
    android:textStyle="bold" 
    android:layout_alignParentRight="true" 
    android:id="@+id/Start_Name" 
    android:textColor="#808080"  
    android:textSize="21sp"    
    android:layout_width="fill_parent"   
    android:layout_height="wrap_content"/> 

    </RelativeLayout> 

我已经市场行47（的原因的崩溃）。谁能告诉我如何解决这个问题？谢谢。

Answer 1

你没有初始化LayoutInflater对象，这就是为什么你得到NullPouinterException。在构造函数中执行此操作：

mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

Answer 2

而不是假，尝试空，并告诉我它是否工作。如果没有，我还有另一个线索。

我的意思是这样的：

convertView = mInflater.inflate(R.layout.start_row, null); 

基督教是正确的。试试这个：

mInflater = LayoutInflater.from(context);