我的代码可以通过drawables的名称获取图片，但由于某种原因，它无法更新。
package com.infonuascape.osrshelper.fragments;
import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.drawable.Drawable;
import android.media.Image;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.support.annotation.Nullable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.toolbox.ImageLoader;
import com.infonuascape.osrshelper.R;
import com.infonuascape.osrshelper.activities.MainActivity;
import com.infonuascape.osrshelper.models.Account;
import org.json.JSONException;
import org.json.JSONObject;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
public class BankViewFragment extends OSRSFragment {
private static final String TAG = "BankViewFragment";
private static Account account;
private ListView lv;
private ImageView iv;
Handler handler;
ArrayList<HashMap<String, String>> ItemList;
public static BankViewFragment newInstance(final Account account) {
BankViewFragment fragment = new BankViewFragment();
Bundle b = new Bundle();
fragment.setArguments(b);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.bank_view, null);
ItemList = new ArrayList<>();
new GetItems().execute();
lv = (ListView) view.findViewById(R.id.list);
handler = new Handler(Looper.getMainLooper());
SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
String nikas = sharedPref.getString("bankname", "null");
return view;
}
public static int getResId(String resourceName, Class<?> c) {
try {
Field idField = c.getDeclaredField(resourceName);
return idField.getInt(idField);
} catch (Exception e) {
throw new RuntimeException("No resource ID found for: "
+ resourceName + " / " + c, e);
}
}
private class GetItems extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... arg0) {
HttpHandler sh = new HttpHandler();
SharedPreferences sharedpreferences = getContext().getSharedPreferences("minescape", Context.MODE_PRIVATE);
String nikas = sharedpreferences.getString("bankname", "null");
String url = "https://api.minesca.pe/game/classic/stats?username=" + nikas;
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "NIKAS: " + nikas);
Log.e(TAG, "ACCOUNT: " + account);
Log.e(TAG, "Response from url: " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
JSONObject items = jsonObj.getJSONObject("bank");
Iterator keys = items.keys();
while(keys.hasNext()) {
String dynamicKey = (String)keys.next();
JSONObject line = items.getJSONObject(dynamicKey);
String item = line.getString("item");
//Integer image = getResId(item, Drawable.class);
final Integer image = getResources().getIdentifier(item, "drawable", getActivity().getPackageName());
String amount = line.getString("amount");
Log.e(TAG, "DAIKTAS: " + item);
Log.e(TAG, "KIEKIS: " + amount);
HashMap<String, String> contact = new HashMap<>();
String itembank = item.replaceAll("i_", "");
String itembanks = itembank.replaceAll("_", " ");
contact.put("name", itembanks);
contact.put("email", amount);
LayoutInflater inflater = LayoutInflater.from(getContext());
View view = inflater.inflate(R.layout.bank_view, null);
lv = (ListView) view.findViewById(R.id.list);
// iv = (ImageView) view.findViewById(R.id.logo);
final ImageView ims = (ImageView) lv.findViewById(R.id.logo);
handler.post(new Runnable() {
public void run() {
if(image != null) {
Log.e(TAG, "kas cia jam netinka?: " + image);
if(image == 0) {
ims.setImageResource(R.drawable.i_noted);
Log.e(TAG, "kas cia jam netinka?: " + image);
} else {
Log.e(TAG, "kas cia jam netinka?: " + image);
ims.setImageResource(image);
}
} else {
Log.e(TAG, "null?: " + image);
}
}
});
ItemList.add(contact);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
new Runnable() {
@Override
public void run() {
Toast.makeText(getContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG).show();
}
};
}
} else {
Log.e(TAG, "Couldn't get json from server.");
new Runnable() {
@Override
public void run() {
Toast.makeText(getContext(),
"Couldn't get json from server!",
Toast.LENGTH_LONG).show();
}
};
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
ListAdapter adapter = new SimpleAdapter(getContext(), ItemList,
R.layout.list_item, new String[]{ "email","name"},
new int[]{R.id.email, R.id.name});
lv.setAdapter(adapter);
}
}
}
错误：
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.infonuascape.osrshelper, PID: 31024
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageResource(int)' on a null object reference
at com.infonuascape.osrshelper.fragments.BankViewFragment$GetItems$1.run(BankViewFragment.java:128)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5637)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:959)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:754)
问题在于，有很多项目，而且大部分都有资源，但有些人不愿意，我想跳过那些没有的人，但主要是问题是，在尝试查看银行时，应用程序崩溃了。
答案 0 :(得分：1)
您无法在非UI线程中更改View
因此，为了解决您的问题，只需访问UI线程中的UI相关内容，例如在onPostExecute()
答案 1 :(得分：0)
不要这样做：除了UI线程之外，不应该在另一个线程中触及视图。
@Override
protected void onPostExecute(Void result) {
-->>>>> DONOT DO THIS --->>>>>lv.setAdapter(adapter);
}