cannot be cast to android.content.pm.PackageInfo o

问题:

my listview contains all app installed.. when i click over one i want open a new activity but actually i get an error.. This is the code:

 @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long row) {
        PackageInfo packageInfo = (PackageInfo) parent.getItemAtPosition(position);
        AppDataActivity appData = (AppDataActivity) getApplicationContext();
        appData.setPackageInfo(packageInfo);
        Toast.makeText(MainActivity.this, position, Toast.LENGTH_LONG).show();
        Intent appInfo = new Intent(MainActivity.this, ApkInfoActivity.class); startActivity(appInfo);

    }

and this is the log:

10-30 14:37:56.780: E/AndroidRuntime(20993): FATAL EXCEPTION: main
10-30 14:37:56.780: E/AndroidRuntime(20993): java.lang.ClassCastException: android.content.pm.ApplicationInfo cannot be cast to android.content.pm.PackageInfo
10-30 14:37:56.780: E/AndroidRuntime(20993):    at com.dd.application.MainActivity.onItemClick(MainActivity.java:370)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.widget.AdapterView.performItemClick(AdapterView.java:297)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.widget.AbsListView.performItemClick(AbsListView.java:1149)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.widget.AbsListView$PerformClick.run(AbsListView.java:2939)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.widget.AbsListView$2.run(AbsListView.java:3622)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.os.Handler.handleCallback(Handler.java:730)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.os.Handler.dispatchMessage(Handler.java:92)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.os.Looper.loop(Looper.java:137)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at android.app.ActivityThread.main(ActivityThread.java:5323)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at java.lang.reflect.Method.invokeNative(Native Method)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at java.lang.reflect.Method.invoke(Method.java:525)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:743)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:559)
10-30 14:37:56.780: E/AndroidRuntime(20993):    at dalvik.system.NativeStart.main(Native Method)

i have already implements the OnItemClickListener in my MainActivity if necessary.. I can't find the problem but if can help i can using a click using ApplicationInfo in this way:

@Override
    public void onItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

       final ApplicationInfo app = applist.get(position);...
...
...

but if i use PackageInfo i can't do it.. How can i solve?

EDIT with adapter

public class ApplicationAdapter extends ArrayAdapter<ApplicationInfo>  { 
    private List<ApplicationInfo> appsList = null; 
    private Context context; 
    private PackageManager packageManager;
    private List<ApplicationInfo> listOfApp;

    public ApplicationAdapter(Context context, int textViewResourceId, 
            List<ApplicationInfo> appsList) { 
        super(context, textViewResourceId, appsList); 
        this.context = context; 
        this.appsList = appsList;
        this.listOfApp = new ArrayList<ApplicationInfo>(); //Added here
        packageManager = context.getPackageManager();
        listOfApp.addAll(appsList);

    } 

    @Override
    public int getCount() { 
        return ((null != appsList) ? appsList.size() : 0); 
    } 

    @Override
    public ApplicationInfo getItem(int position) { 
        return ((null != appsList) ? appsList.get(position) : null); 
    } 

    @Override
    public long getItemId(int position) { 
        return position; 
    } 

    @Override
    public View getView(int position, View convertView, ViewGroup parent) { 
        View view = convertView; 
        if (null == view) { 
            LayoutInflater layoutInflater = (LayoutInflater) context 
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
            view = layoutInflater.inflate(R.layout.snippet_list_row, null); 
        } 

        ApplicationInfo data = appsList.get(position); 
        if (null != data) { 
            TextView appName = (TextView) view.findViewById(R.id.app_name); 
            TextView packageName = (TextView) view.findViewById(R.id.app_paackage); 
            ImageView iconview = (ImageView) view.findViewById(R.id.app_icon); 

            appName.setText(data.loadLabel(packageManager)); 
            packageName.setText(data.packageName); 
            iconview.setImageDrawable(data.loadIcon(packageManager)); 
        } 
        return view; 
    } 



 // Filter Class
    public void filter(String charText) {
        charText = charText.toLowerCase(Locale.getDefault());
        appsList.clear();
        if (charText.length() == 0) {
            appsList.addAll(listOfApp);
        } 
        else
        {
            for (ApplicationInfo ai : listOfApp) 
            {
                if (ai.loadLabel(packageManager).toString().toLowerCase(Locale.getDefault()).contains(charText)) 
                {
                    appsList.add(ai);
                }
            }
        }
        notifyDataSetChanged();
    }

}

AppData: public class AppDataActivity extends Application {

    PackageInfo packageInfo;

    public PackageInfo getPackageInfo() {
        return packageInfo;
    }

    public void setPackageInfo(PackageInfo packageInfo) {
        this.packageInfo = packageInfo;
    }
}

回答1:

You adapter is filled up with a collections of ApplicationInfo, so the correct cast is to ApplicationInfo.

change

PackageInfo packageInfo = (PackageInfo) parent.getItemAtPosition(position);

with

ApplicationInfo packageInfo = (ApplicationInfo) parent.getItemAtPosition(position);