Question

我在gridview中显示数据。但它给了我nullpointerexception。当我不通过

显示数据时

oid.setText(sdata.getOid()); then it is giving me values and not any exception.

但是当我想在textview中显示数据时。它给了我nullpointer异常。

这是代码： -

griddata gdata = new griddata(search.this,R.layout.griditem,r);
gridview.setAdapter(gdata);

public class griddata extends ArrayAdapter<searchdata>
{
Context context;
private ArrayList<searchdata> items;

public griddata(Context context, int textViewResourceId, ArrayList<searchdata> items) {
    super(context, textViewResourceId, items);
    this.items = items;
}

 @Override
 public int getCount() 
  {
 //return numbers of element u want on the grid
  return items.size();
 }

 @Override
 public View getView(int position, View convertView, ViewGroup parent) 
  {
   View v;
   if (convertView == null) {
       LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
       v = new View(context);
       v = vi.inflate(R.layout.griditem, null);
   } else
   {
       v = convertView;
   }

   searchdata sdata = items.get(position);
   System.out.println("The data is "+sdata.getOid());
   if(sdata != null)
   {

    TextView oid = (TextView) findViewById(R.id.oid);
    oid.setText(sdata.getOid()); 
/*    TextView odate = (TextView) findViewById(R.id.odate); 
    TextView osdate = (TextView) findViewById(R.id.osdate); 
    TextView semail = (TextView) findViewById(R.id.semail); 
    TextView ssaddress = (TextView) findViewById(R.id.ssaddress); 
    TextView shipzip = (TextView) findViewById(R.id.shipzip); 
    TextView scost = (TextView) findViewById(R.id.scost); 
    TextView noofi = (TextView) findViewById(R.id.noofi); 
    TextView noofc = (TextView) findViewById(R.id.noofc); 
    TextView handfee = (TextView) findViewById(R.id.handfee); 

    oid.setText(sdata.getOid()); 
    /*odate.setText(sdata.getOdate());
    osdate.setText(sdata.getOsdate());
    semail.setText(sdata.getSemail());
    ssaddress.setText(sdata.getSsaddress());
    shipzip.setText(sdata.getSzip());
    scost.setText(sdata.getScost());
    noofi.setText(sdata.getNoofi());
    noofc.setText(sdata.getNoofc());
    handfee.setText(sdata.getHannlgfee());*/

   }

   return v;}

@Override
 public searchdata getItem(int arg0) {

  return items.get(arg0);
 }

@Override
public long getItemId(int arg0) {
 // TODO Auto-generated method stub
 return arg0;} }

和我的getitem.xml： -

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:fillViewport="true">
     <LinearLayout
        android:id="@+id/header"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:paddingBottom="5dip"
        android:paddingTop="5dip" 
        android:orientation="horizontal">

                <TextView
        android:id="@+id/oid"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"


        android:layout_marginLeft="17dp"
        android:text="TextView" />

                <TextView
        android:id="@+id/odate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"


        android:layout_marginLeft="17dp"
        android:text="TextView" />

                  <TextView
        android:id="@+id/osdate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                   <TextView
        android:id="@+id/semail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                   <TextView
        android:id="@+id/ssaddress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                      <TextView
        android:id="@+id/shipzip"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                      <TextView
        android:id="@+id/scost"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                    <TextView
        android:id="@+id/noofi"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                     <TextView
        android:id="@+id/noofc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

                     <TextView
        android:id="@+id/handfee"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:layout_marginLeft="17dp"
        android:text="TextView" />

    </LinearLayout>

05-15 15:58:48.646: E/AndroidRuntime(2500): java.lang.NullPointerException
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewConfiguration.get(ViewConfiguration.java:332)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.View.<init>(View.java:3236)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at com.example.ship2impress.search$griddata.getView(search.java:297)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.AbsListView.obtainView(AbsListView.java:2271)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.GridView.onMeasure(GridView.java:1030)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.View.measure(View.java:15172)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:617)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:399)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.View.measure(View.java:15172)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4816)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.View.measure(View.java:15172)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.View.measure(View.java:15172)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4816)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2148)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.View.measure(View.java:15172)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1850)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1102)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1275)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1000)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4214)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.Choreographer.doCallbacks(Choreographer.java:555)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.Choreographer.doFrame(Choreographer.java:525)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.os.Handler.handleCallback(Handler.java:615)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.os.Handler.dispatchMessage(Handler.java:92)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.os.Looper.loop(Looper.java:137)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at android.app.ActivityThread.main(ActivityThread.java:4745)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at java.lang.reflect.Method.invokeNative(Native Method)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at java.lang.reflect.Method.invoke(Method.java:511)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
05-15 15:58:48.646: E/AndroidRuntime(2500):     at dalvik.system.NativeStart.main(Native Method)

我认为问题可能出在getitem.xml中。请帮帮我。谢谢你的时间安排。

Answer 1

使用以下更改

public griddata(Context context, int textViewResourceId, ArrayList<searchdata> items) {
super(context, textViewResourceId, items);
this.items = items;
this.context = context ;

}

在获取视图中

if (convertView == null) {
 convertView = LayoutInflater.from(conetxt).inflate(R.layout.griditem, null);
  }

和

       TextView oid = (TextView) convertView.findViewById(R.id.oid);

Answer 2

更改此

TextView oid = (TextView) findViewById(R.id.oid);
oid.setText(sdata.getOid());

到这个

TextView oid = (TextView) v.findViewById(R.id.oid);
oid.setText(sdata.getOid());

GridView正在提供NullPointerException

2 个答案: