當通過實現可過濾的java類的意圖傳遞數據時顯示錯誤

Question

這是我的完整的java類代碼。 它顯示空指針異常。我還添加了logcat屏幕截圖。我試圖解決這個問題，但沒辦法。請儘可能幫助我。

public class AppAdapter extends RecyclerView.Adapter<AppAdapter.AppViewHolder> implements Filterable { 

// Load Settings 
private AppPreferences appPreferences; 


// AppAdapter variables 
private List<AppInfo> appList; 
private List<AppInfo> appListSearch; 
private Context context; 


public AppAdapter(List<AppInfo> appList, Context context) { 
    this.appList = appList; 
    this.context = context; 
    this.appPreferences = SystemInfoManager.getAppPreferences(); 

} 

@Override 
public int getItemCount() { 
    return appList.size(); 

} 

public void clear() { 
    appList.clear(); 
    notifyDataSetChanged(); 
} 

@Override 
public void onBindViewHolder(AppViewHolder appViewHolder, int i) { 
    AppInfo appInfo = appList.get(i); 
    appViewHolder.vName.setText(appInfo.getName()); 
    appViewHolder.vApk.setText(appInfo.getAPK()); 
    appViewHolder.vIcon.setImageDrawable(appInfo.getIcon()); 

    setButtonEvents(appViewHolder, appInfo); 

} 


private void setButtonEvents(AppViewHolder appViewHolder, final AppInfo appInfo) { 
    ButtonFlat appAbout = appViewHolder.vAbout; 
    ButtonFlat appShare = appViewHolder.vShare; 
    final ImageView appIcon = appViewHolder.vIcon; 
    final CardView cardView = appViewHolder.vCard; 

    appAbout.setBackgroundColor(Color.BLUE); 
    appShare.setBackgroundColor(Color.BLUE); 

    appAbout.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 

      Activity activity = (Activity) context; 

      Intent intent = new Intent(context, AppActivity.class); 
      intent.putExtra("app_name", appInfo.getName()); 
      intent.putExtra("app_apk", appInfo.getAPK()); 
      intent.putExtra("app_version", appInfo.getVersion()); 
      intent.putExtra("app_source", appInfo.getSource()); 
      intent.putExtra("app_data", appInfo.getData()); 
      Bitmap bitmap = ((BitmapDrawable) appInfo.getIcon()).getBitmap(); 
      intent.putExtra("app_icon", bitmap); 
      intent.putExtra("app_isSystem", appInfo.isSystem()); 

      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { 
       String transitionName = context.getResources().getString(R.string.transition_app_icon); 

       ActivityOptions transitionActivityOptions = ActivityOptions.makeSceneTransitionAnimation(activity, appIcon, transitionName); 
       context.startActivity(intent, transitionActivityOptions.toBundle()); 
      } else { 
       context.startActivity(intent); 
       activity.overridePendingTransition(R.anim.slide_in_right, R.anim.fade_back); 
      } 
     } 
    }); 


    appShare.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      UtilsApp.copyFile(appInfo); 
      Intent shareIntent = UtilsApp.getShareIntent(UtilsApp.getOutputFilename(appInfo)); 
      context.startActivity(Intent.createChooser(shareIntent, 
        String.format(context.getResources().getString(R.string.send_to), appInfo.getName()))); 
     } 
    }); 


    cardView.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 

      Activity activity = (Activity) context; 


      Intent intent = new Intent(context, AppActivity.class); 
      intent.putExtra("app_name", appInfo.getName()); 
      intent.putExtra("app_apk", appInfo.getAPK()); 
      intent.putExtra("app_version", appInfo.getVersion()); 
      intent.putExtra("app_source", appInfo.getSource()); 
      intent.putExtra("app_data", appInfo.getData()); 
      Bitmap bitmap = ((BitmapDrawable) appInfo.getIcon()).getBitmap(); 
      intent.putExtra("app_icon", bitmap); 
      intent.putExtra("app_isSystem", appInfo.isSystem()); 

      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { 
       String transitionName = context.getResources().getString(R.string.transition_app_icon); 

       ActivityOptions transitionActivityOptions = ActivityOptions.makeSceneTransitionAnimation(activity, appIcon, transitionName); 
       context.startActivity(intent, transitionActivityOptions.toBundle()); 
      } else { 
       context.startActivity(intent); 
       activity.overridePendingTransition(R.anim.slide_in_right, R.anim.fade_back); 
      } 
     } 
    }); 


} 

public Filter getFilter() { 
    return new Filter() { 
     @Override 
     protected FilterResults performFiltering(CharSequence charSequence) { 
      final FilterResults oReturn = new FilterResults(); 
      final List<AppInfo> results = new ArrayList<>(); 
      if (appListSearch == null) { 
       appListSearch = appList; 
      } 
      if (charSequence != null) { 
       if (appListSearch != null && appListSearch.size() > 0) { 
        for (final AppInfo appInfo : appListSearch) { 
         if (appInfo.getName().toLowerCase().contains(charSequence.toString())) { 
          results.add(appInfo); 
         } 
        } 
       } 
       oReturn.values = results; 
       oReturn.count = results.size(); 
      } 
      return oReturn; 
     } 

     @Override 
     protected void publishResults(CharSequence charSequence, FilterResults filterResults) { 
      if (filterResults.count > 0) { 
       InstalledAppsFragment.setResultsMessage(false); 
      } else { 
       InstalledAppsFragment.setResultsMessage(true); 
      } 
      appList = (ArrayList<AppInfo>) filterResults.values; 
      notifyDataSetChanged(); 
     } 
    }; 
} 


@Override 
public AppViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) { 
    View appAdapterView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.app_layout, viewGroup, false); 
    return new AppViewHolder(appAdapterView); 
} 

public static class AppViewHolder extends RecyclerView.ViewHolder { 
    protected TextView vName; 
    protected TextView vApk; 
    protected ImageView vIcon; 
    protected ButtonFlat vAbout; 
    protected ButtonFlat vShare; 
    protected CardView vCard; 

    public AppViewHolder(View v) { 
     super(v); 
     vName = (TextView) v.findViewById(R.id.txtName); 
     vApk = (TextView) v.findViewById(R.id.txtApk); 
     vIcon = (ImageView) v.findViewById(R.id.imgIcon); 
     vAbout = (ButtonFlat) v.findViewById(R.id.btnExtract); 
     vShare = (ButtonFlat) v.findViewById(R.id.btnShare); 
     vCard = (CardView) v.findViewById(R.id.app_card); 

    } 
} 

}

這裏是logcat的消息：

https://i.stack.imgur.com/vVOr7.jpg

如果可能的話，請給我一些解決方案。 我已經使用context.getBaseContext（），但它也給錯誤。

Answer 1

，而不是分析上下文活動使用getActiviy（）

Intent intent = new Intent(getActivity(), AppActivity.class); 

Answer 2

嘗試改變這一行 相反

Intent intent = new Intent(context, AppActivity.class); 

到

Intent intent = new Intent(YourActivityName.this, AppActivity.class);