Question

我正在尝试在片段中创建一个带有图片库的应用，但不会在代码中出现错误，但会在下面收到此错误。任何帮助都会很棒，只有初学者。如果您想了解更多细节，请询问。

认为它与第34行有关：GridView gridview =（GridView）getView（）。findViewById（R.id.gridview）;

代码：

 public class Fragment_3 extends Fragment{
  private static View view;
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      if (view != null) {
          ViewGroup parent = (ViewGroup) view.getParent();
          if (parent != null)
              parent.removeView(view);
      }
      try {
          view = inflater.inflate(R.layout.fragment_3, container, false);
      } catch (InflateException e) {
      }

     GridView gridview = (GridView) getView().findViewById(R.id.gridview);
        gridview.setAdapter(new ImageAdapter(this.getActivity()));

        gridview.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                Toast.makeText(Fragment_3.this.getActivity(), "" + position, Toast.LENGTH_SHORT).show();
            }
        });

        return view;
}

  public class ImageAdapter extends BaseAdapter {
        private Context mContext;

        public ImageAdapter(Context c) {
            mContext = c;
        }

        public int getCount() {
            return mThumbIds.length;
        }

        public Object getItem(int position) {
            return null;
        }

        public long getItemId(int position) {
            return 0;
        }

        // create a new ImageView for each item referenced by the Adapter
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView imageView;
            if (convertView == null) {  // if it's not recycled, initialize some attributes
                imageView = new ImageView(mContext);
                imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(8, 8, 8, 8);
            } else {
                imageView = (ImageView) convertView;
            }

            imageView.setImageResource(mThumbIds[position]);
            return imageView;
        }

        // references to our images
        private Integer[] mThumbIds = {
                R.drawable.sample_2, R.drawable.sample_3,
                R.drawable.sample_4, R.drawable.sample_5,
                R.drawable.sample_6, R.drawable.sample_7,
                R.drawable.sample_0, R.drawable.sample_1,
                R.drawable.sample_2, R.drawable.sample_3,
                R.drawable.sample_4, R.drawable.sample_5,
                R.drawable.sample_6, R.drawable.sample_7,
                R.drawable.sample_0, R.drawable.sample_1,
                R.drawable.sample_2, R.drawable.sample_3,
                R.drawable.sample_4, R.drawable.sample_5,
                R.drawable.sample_6, R.drawable.sample_7
        };
    }
 }

错误

 06-24 14:02:27.385: E/AndroidRuntime(3959): FATAL EXCEPTION: main
 06-24 14:02:27.385: E/AndroidRuntime(3959): java.lang.NullPointerException
06-24 14:02:27.385: E/AndroidRuntime(3959):     at com.bottlecapp.ahmetmikko.Fragment_3.onCreateView(Fragment_3.java:34)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1460)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:911)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:429)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.os.Handler.handleCallback(Handler.java:725)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.os.Handler.dispatchMessage(Handler.java:92)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.os.Looper.loop(Looper.java:137)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at android.app.ActivityThread.main(ActivityThread.java:5041)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at java.lang.reflect.Method.invokeNative(Native Method)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at java.lang.reflect.Method.invoke(Method.java:511)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-24 14:02:27.385: E/AndroidRuntime(3959):     at dalvik.system.NativeStart.main(Native Method)

Answer 1

你有没有理由在onCreate上有一个try catch块导致返回View？语法明智，你getView()上不需要GridView，你可以GridView gridview = (GridView) findViewById(R.id.gridview);但是看起来你得到的是NullPointerException。你能告诉我们第34行是什么吗？

碎片错误中的图像库

1 个答案: