我目前正在研究一个应用程序,其中包含登录时的朋友列表和用户配置文件。当用户点击朋友列表中的朋友时,我希望他们被引导至该朋友的个人资料页面。为此,我一直试图从列表视图中单击的用户提取特定对象ID,然后将其传递到下一个活动,我使用它来运行所有用户的查询其他属性(名称,电子邮件,家乡等)。我已经想出了如何通过意图传递数据,但我从点击列表项获取用户标识时遇到各种麻烦。我的onItemCLick代码如下。从onListItemClick获取分析对象ID
```
public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
ParseObject item = (ParseObject) l.getAdapter().getItem(position);
String objectID = item.getObjectId().toString();
Intent intent = new Intent(getActivity(), FriendsProfileActivity.class);
intent.putExtra("ID", objectID);
startActivity(intent);
```
我也尝试过这种东西没有用的。
```
public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
ParseObject item = (ParseObject) l.getAdapter().getItem(position);
item.saveInBackground(new SaveCallback() {
@Override
public void done(ParseException e) {
if(e == null) {
String objectID = item.getObjectId();
Log.e(TAG, objectID);
Intent intent = new Intent(getActivity(), FriendsProfileActivity.class);
intent.putExtra("ID", objectID);
startActivity(intent);
}
else {
Log.e(TAG, e.getMessage());
}
}
});
}
```
在这两种情况下,应用程序崩溃,当我点击列表视图中的用户。我怎样才能成功地从用户点击的对象ID,并将其传递?
编辑:这是logcat错误。
Process: com.richluick.ribbit, PID: 2194 java.lang.ClassCastException: java.lang.String cannot be cast to com.parse.ParseObject at com.richluick.ribbit.FriendsFragment.onListItemClick(FriendsFragment.java:83) at android.support.v4.app.ListFragment$2.onItemClick(ListFragment.java:58) at android.widget.AdapterView.performItemClick(AdapterView.java:299) at android.widget.AbsListView.performItemClick(AbsListView.java:1113) at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904) at android.widget.AbsListView$3.run(AbsListView.java:3638) at android.os.Handler.handleCallback(Handler.java:733) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5017) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) at dalvik.system.NativeStart.main(Native Method)
编辑:这是包括查询和列表适配器活动的完整代码。 package com.richluick.ribbit;
import android.app.AlertDialog;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import com.parse.FindCallback;
import com.parse.ParseException;
import com.parse.ParseObject;
import com.parse.ParseQuery;
import com.parse.ParseRelation;
import com.parse.ParseUser;
import com.parse.SaveCallback;
import java.util.List;
public class FriendsFragment extends android.support.v4.app.ListFragment {
public static final String TAG = FriendsFragment.class.getSimpleName();
protected List<ParseUser> mFriends;
protected ParseRelation<ParseUser> mFriendsRelation;
protected ParseUser mCurrentUser;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_friends, container, false);
return rootView;
}
@Override
public void onResume() {
super.onResume();
mCurrentUser = ParseUser.getCurrentUser();
mFriendsRelation = mCurrentUser.getRelation(ParseConstants.KEY_FRIENDS_RELATION);
getActivity().setProgressBarIndeterminateVisibility(true);
ParseQuery<ParseUser> query = mFriendsRelation.getQuery();
query.addAscendingOrder(ParseConstants.KEY_USERNAME);
query.findInBackground(new FindCallback<ParseUser>() {
@Override
public void done(List<ParseUser> friends, ParseException e) {
getActivity().setProgressBarIndeterminateVisibility(false);
if (e == null) {
mFriends = friends;
String[] usernames = new String[mFriends.size()];
int i = 0;
for (ParseUser user : mFriends) {
usernames[i] = user.getUsername();
i++;
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getListView().getContext(),
android.R.layout.simple_list_item_1, usernames);
setListAdapter(adapter);
}
else {
Log.e(TAG, e.getMessage());
AlertDialog.Builder builder = new AlertDialog.Builder(getListView().getContext());
builder.setTitle(R.string.error_title)
.setMessage(e.getMessage())
.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}
}
});
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
final ParseObject item = (ParseObject) l.getAdapter().getItem(position);
item.saveInBackground(new SaveCallback() {
@Override
public void done(ParseException e) {
if(e == null) {
String objectID = item.getObjectId();
Log.e(TAG, objectID);
Intent intent = new Intent(getActivity(), FriendsProfileActivity.class);
intent.putExtra("ID", objectID);
startActivity(intent);
}
else {
Log.e(TAG, e.getMessage());
}
}
});
}
}
请发布您的logcat – MrEngineer13 2014-08-29 18:38:24
后Yout LogCat看到的exeption或错误。 – 2014-08-29 19:21:41
请在活动中发布其余代码 - 即,查询并加载列表视图的代码。这有助于理解你的问题 - logcat错误似乎意味着适配器中的内容是以字符串开始的,而不是ParseObjects – user2163298 2014-08-29 21:50:19