片段上的自定義GridView上的NullPointerException

Question

我已經在片段中制作了自定義gridview

首先我在logcat上顯示錯誤

01-30 19:01:02.266: E/AndroidRuntime(15600): FATAL EXCEPTION: main
01-30 19:01:02.266: E/AndroidRuntime(15600): Process: com.example.achessapp, PID: 15600
01-30 19:01:02.266: E/AndroidRuntime(15600): java.lang.NullPointerException
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.AbsListView.obtainView(AbsListView.java:2426)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.GridView.onMeasure(GridView.java:1044)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:824)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:500)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:926)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:607)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5374)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:340)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2343)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.View.measure(View.java:16980)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2252)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1315)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1513)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1192)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6231)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:816)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.Choreographer.doCallbacks(Choreographer.java:619)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.Choreographer.doFrame(Choreographer.java:588)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:802)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.os.Handler.handleCallback(Handler.java:808)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.os.Handler.dispatchMessage(Handler.java:103)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.os.Looper.loop(Looper.java:193)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at android.app.ActivityThread.main(ActivityThread.java:5395)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at java.lang.reflect.Method.invokeNative(Native Method)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at java.lang.reflect.Method.invoke(Method.java:515)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:837)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:653)
01-30 19:01:02.266: E/AndroidRuntime(15600):    at dalvik.system.NativeStart.main(Native Method)

Java代碼是

class UniteFragment extends Fragment implements OnClickListener {
    View mView;
    Activity mActivity;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        mView = inflater.inflate(R.layout.unite_screen, container, false);


        GridView mGridUnite = (GridView) mView
                .findViewById(R.id.grdGrupOfUnite);

        mGridUnite.setAdapter(new MyBaseAdapter());
        return mView;
    }

    @Override
    public void onAttach(Activity activity) {
        mActivity = activity;
        super.onAttach(activity);
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {

        }
    }

    class MyBaseAdapter extends BaseAdapter {
        LayoutInflater mInflator;

        public MyBaseAdapter() {
            mInflator = mActivity.getLayoutInflater();
        }

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return 3;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder viewHolder;
            if (convertView == null) {
                convertView = mInflator.inflate(R.layout.unite_grup_item, null);
                viewHolder = new ViewHolder();
                viewHolder.ivUser = (CircularImageView) convertView
                        .findViewById(R.id.ivGrupIcon);
                viewHolder.tvCounter = (TextView) convertView
                        .findViewById(R.id.tvRedCounter);
                viewHolder.tvName = (TextView) convertView
                        .findViewById(R.id.tvName);
                convertView.setTag(viewHolder);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }

            viewHolder.ivUser.setImageResource(R.drawable.unite_item);
            viewHolder.tvCounter.setText("" + position);
            viewHolder.tvName.setText("User " + position);
            return null;
        }

        class ViewHolder {
            CircularImageView ivUser;
            TextView tvCounter;
            TextView tvName;
            int position;
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

    }
}

R.layout.unit_screen.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/background" >

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:adjustViewBounds="true"
        android:src="@drawable/unite_bg" />

    <GridView
        android:id="@+id/grdGrupOfUnite"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:numColumns="3" >
    </GridView>

</RelativeLayout>

unite_grup_item.xml是

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >

    <com.example.achessapp.widget.CircularImageView
        android:id="@+id/ivGrupIcon"
        android:layout_width="@dimen/icon_size"
        android:layout_height="@dimen/icon_size"
        android:background="@android:color/white"
        android:src="@drawable/unite_item" />

    <TextView
        android:id="@+id/tvRedCounter"
        android:layout_width="20dp"
        android:layout_height="20dp"
        android:layout_alignParentRight="true"
        android:background="@drawable/red_counter_shape"
        android:text="1" />

    <TextView
        android:id="@+id/tvName"
        android:layout_width="20dp"
        android:layout_height="20dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:text="1"
        android:textColor="@android:color/black" />

</RelativeLayout>

如果有人可以解決此問題，請幫助我找出解決方案

Answer 1

返回為當前行准備的convertView ，而不是getView方法中的null