我的应用程序在启动后会保持崩溃状态。在错误部分中显示NullPointerException。如何解决这个问题？
作为错误建议我的RecipeListFragment.java文件是：
public class RecipeListFragment extends Fragment {
MyDatabase db;
boolean isfav = false;
Context context;
ListView lvrecipe;
ArrayList<RecipePojo> recipelist = new ArrayList<RecipePojo>();
// private MoPubView adView;
LinearLayout ll;
DisplayImageOptions options;
private ProgressDialog progress;
int position;
String recipeid;
int checkcounter = 0;
private Custom_Adapter adapter;
public RecipeListFragment() {
}
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_recipe_list_actvity, container, false);
context = getActivity();
lvrecipe = (ListView) rootView.findViewById(R.id.lvrecipe);
// adView = (MoPubView)rootView. findViewById(R.id.mopub_sample_ad);
new getrecipe().execute();
db = new MyDatabase(getActivity());
// recipelist = DataManager.recipelist;
position = DataManager.selectedposition;
adapter = new Custom_Adapter(getActivity());
adapter.notifyDataSetChanged();
lvrecipe.setAdapter(adapter);
lvrecipe.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
DataManager.selectedposition = position;
Intent i = new Intent(getActivity(), RecipeDescription.class);
i.putExtra("cusinename", DataManager.cusinename);
startActivity(i);
getActivity().finish();
}
});
// adddisplay();
return rootView;
}
@Override
public void onResume() {
super.onResume();
}
public class Custom_Adapter extends BaseAdapter {
private LayoutInflater mInflater;
public Custom_Adapter(Context c) {
mInflater = LayoutInflater.from(c);
}
@Override
public int getCount() {
if (recipelist != null) {
return recipelist.size();
} else {
return 0;
}
}
@Override
public Object getItem(int position) {
if (recipelist != null) {
return recipelist.get(position);
} else {
return 0;
}
}
@Override
public long getItemId(int position) {
if (recipelist != null) {
return position;
} else {
return 0;
}
}
@SuppressWarnings("deprecation")
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.recipelist, null);
holder = new ViewHolder();
holder.txttile = (TextView) convertView.findViewById(R.id.txttile);
holder.imgrecipe = (ImageView) convertView.findViewById(R.id.imgrecipe);
holder.fav_unfav = (ImageView) convertView.findViewById(R.id.fav_unfav);
holder.ratingbar = (RatingBar) convertView.findViewById(R.id.ratingbar);
holder.txtduration = (TextView) convertView.findViewById(R.id.txtduration);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if (recipelist != null) {
recipeid = recipelist.get(position).getRecipeid();
checkcounter = db.checkrecipefav(recipeid);
}
if (checkcounter > 0) {
isfav = true;
} else {
isfav = false;
}
db.close();
if (isfav) {
holder.fav_unfav.setImageResource(R.drawable.favourite);
} else {
holder.fav_unfav.setImageResource(R.drawable.favourites);
}
Typeface face1 = Typeface.createFromAsset(getActivity().getAssets(), "sinkin_sans_300_light.ttf");
Typeface face2 = Typeface.createFromAsset(getActivity().getAssets(), "sinkin_sans_400_regular.ttf");
holder.txttile.setTypeface(face2);
holder.txtduration.setTypeface(face1);
holder.txttile.setText(recipelist.get(position).getRecipename());
try {
String[] prep = recipelist.get(position).getPrep_time().split(" ");
String[] cook = recipelist.get(position).getCooking_time().split(" ");
int totalTime = Integer.parseInt(prep[0]) + Integer.parseInt(cook[0]);
holder.txtduration.setText(""+totalTime+" min");
} catch (NumberFormatException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
String url = DataManager.photourl + "recipe/" + recipelist.get(position).getRecipeid() + ".jpg";
try {
url = URLDecoder.decode(url, "UTF-8");
url = url.replaceAll(" ", "%20");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
if (recipelist.get(position).getVideo_link().equals("none")) {
// holder.imgvideo.setVisibility(View.GONE);
}
String rating = recipelist.get(position).getRatings();
if (rating != null && rating.trim().length() > 0) {
holder.ratingbar.setRating(Float.valueOf(rating));
}
if (holder.imgrecipe != null) {
if (url != null && url.trim().length() > 0) {
//final ProgressBar pbar = holder.pbar;
final ImageView imageView = holder.imgrecipe;
//final RelativeLayout imgRL = holder.imageRL;
ImageLoader.getInstance().displayImage(url, holder.imgrecipe, options, new SimpleImageLoadingListener() {
@Override
public void onLoadingComplete(String imageUri,
View view, Bitmap loadedImage) {
super.onLoadingComplete(imageUri, view, loadedImage);
imageView.setAdjustViewBounds(true);
}
@Override
public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
super.onLoadingFailed(imageUri, view, failReason);
}
@Override
public void onLoadingStarted(String imageUri, View view) {
super.onLoadingStarted(imageUri, view);
}
});
} else {
}
}
return convertView;
}
class ViewHolder {
TextView txttile, txtduration;
ImageView imgrecipe;
ImageView fav_unfav;
RatingBar ratingbar;
}
}
public class getrecipe extends AsyncTask<String, Void, String> {
boolean response = false;
@Override
protected void onPreExecute() {
//progress = ProgressDialog.show(context, "Getting Data...","Please wait....");
progress = new ProgressDialog(getActivity());
progress.setMessage("Please wait....");
progress.show();
}
@Override
protected String doInBackground(String... params) {
response = APIManager.getrecipebycusine(DataManager.CUISINE_ID);
return "";
}
@Override
protected void onPostExecute(String result) {
progress.cancel();
if (response) {
if (DataManager.status.equalsIgnoreCase("1")) {
recipelist = DataManager.recipelist;
adapter.notifyDataSetChanged();
//Intent i = new Intent(getActivity(),RecipeListActvity.class);
//startActivity(i);
} else {
connectionerror();
}
} else {
connectionerror();
}
}
@Override
protected void onProgressUpdate(Void... values) {
}
}
public void alert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity());
alertDialog.setTitle("No Recipe!");
alertDialog.setMessage("No Recipe for this Cusine");
alertDialog.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
}
});
alertDialog.show();
}
private static class AnimateFirstDisplayListener extends SimpleImageLoadingListener {
static final List<String> displayedImages = Collections.synchronizedList(new LinkedList<String>());
@Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
if (loadedImage != null) {
ImageView imageView = (ImageView) view;
boolean firstDisplay = !displayedImages.contains(imageUri);
if (firstDisplay) {
FadeInBitmapDisplayer.animate(imageView, 500);
displayedImages.add(imageUri);
}
}
}
}
public void connectionerror() {
// if (getActivity() == null) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity());
alertDialog.setTitle("Error!");
alertDialog.setMessage("Connection Lost ! Try Again");
alertDialog.setPositiveButton("Retry",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
new getrecipe().execute();
}
});
alertDialog.show();
}
//}}
错误：
Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference
at com.raccoonfinger.dessert.RecipeListFragment$Custom_Adapter.getView(RecipeListFragment.java:207)
at android.widget.AbsListView.obtainView(AbsListView.java:2344)
at android.widget.ListView.makeAndAddView(ListView.java:1864)
at android.widget.ListView.fillDown(ListView.java:698)
at android.widget.ListView.fillFromTop(ListView.java:759)
at android.widget.ListView.layoutChildren(ListView.java:1659)
at android.widget.AbsListView.onLayout(AbsListView.java:2148)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1076)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:1043)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1076)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:494)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
at android.view.View.layout(View.java:15614)
at android.view.ViewGroup.layout(ViewGroup.java:4968)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2102)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1859)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1077)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5884)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5312)
at java.lang.reflect.Method.invoke(Method.java)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)
答案 0 :(得分：0)
您的布局recipelist.xml不包含ID为TextView或txttile的{{1}}。
答案 1 :(得分：0)
我确定你的问题是因为这些
holder.txttile.setTypeface(face2);
holder.txtduration.setTypeface(face1);
您正在空引用上调用setTypeface。你必须找到这个案例持有者是什么null或者txttile OR txtduration OR face1 OR face2。
大多数机会是关于持有者，txttile，txtduration。
答案 2 :(得分：0)
getView()中您需要向方法mInflater.inflate(R.layout.recipelist, null);添加三个参数，就像这个mInflater.inflate(R.layout.recipelist, parent, false);一样。