我正在创建一个使用Hashtag的应用。到目前为止,我使用AutoLinkTextClick!并且一切正常,除非有人点击已识别的主题标签时应用程序崩溃并出现错误:
java.lang.NullPointerException:尝试调用虚方法 ' java.lang.String android.content.Context.getPackageName()'在null 对象参考
所以我几乎已经阅读了StackOverflow关于可能导致它的原因并且人们建议使用getContext()
或getActvity()
,但这两者都不起作用,因为我试图从一个适配器,而不是来自扩展活动或片段的类,所以我非常感谢你们的帮助。
非常感谢您在这件事上的时间和帮助。下面是我正在显示的适配器和错误的代码:)
package com.android.msahakyan.expandablenavigationdrawer.adapter;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v4.app.FragmentManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.support.v7.app.AlertDialog;
import com.android.msahakyan.expandablenavigationdrawer.AboutUsActivity;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
import com.android.msahakyan.expandablenavigationdrawer.R;
import com.android.msahakyan.expandablenavigationdrawer.activity.FeedImageView;
import com.android.msahakyan.expandablenavigationdrawer.model.Feed;
import com.android.msahakyan.expandablenavigationdrawer.others.AppController;
import com.luseen.autolinklibrary.AutoLinkMode;
import com.luseen.autolinklibrary.AutoLinkOnClickListener;
import com.luseen.autolinklibrary.AutoLinkTextView;
import java.util.List;
public class FeedsListAdapter extends RecyclerView.Adapter<FeedsListAdapter.MyHolder> {
private Activity activity;
private LayoutInflater inflater;
private List<Feed> feedItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
//ImageLoader imageLoader = VolleySingleton.getInstance(context).getImageLoader()
public FragmentManager f_manager;
public FeedsListAdapter(Activity activity, List<Feed> feedItems) {
this.activity = activity;
this.feedItems = feedItems;
}
//INITIALIE VH
//@Override
public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v= LayoutInflater.from(parent.getContext()).inflate(R.layout.feeds_home_row,parent,false);
MyHolder holder=new MyHolder(v);
return holder;
}
//BIND DATA
// @Override
public void onBindViewHolder(MyHolder holder, int position) {
//ImageLoader imageLoader = AppController.getInstance().getImageLoader();
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
final Feed f = feedItems.get(position);
//Post images
holder.picture.setImageUrl(f.getPictureUrl(), imageLoader); // displays company profile image on post
holder.sms_image.setImageUrl(f.getMessagePictureUrl(), imageLoader); // displays post image on post
//autoLinkTextView.enableUnderLine();
holder.messages.addAutoLinkMode(AutoLinkMode.MODE_HASHTAG);
holder.messages.setAutoLinkText("this the sample message #test i need to test hashtag onClink and launch intent"); //
holder.messages.setAutoLinkOnClickListener(new AutoLinkOnClickListener() {
@Override
public void onAutoLinkTextClick(AutoLinkMode autoLinkMode, String matchedText) {
Intent intent = new Intent(activity, AboutUsActivity.class);
intent.putExtra("companyId", f.getCompanyId());
activity.startActivity(intent);
}
});
//holder.messages.setText(f.getMessage());
//Linkify.addLinks(holder.messages, Linkify.ALL); //detect link that are in a message
holder.date_created.setText(f.getDateCreated());
holder.company.setText(f.getCompany());
}
/*
TOTAL ITEMS
*/
//@Override
public int getItemCount() {
return feedItems.size();
}
/*
ADD DATA TO ADAPTER
*/
public void add(Feed s) {
feedItems.add(s);
notifyDataSetChanged();
}
/*
CLEAR DATA FROM ADAPTER
*/
public void clear() {
feedItems.clear();
notifyDataSetChanged();
}
/*
VIEW HOLDER CLASS
*/
class MyHolder extends RecyclerView.ViewHolder {
FeedImageView sms_image;
NetworkImageView picture;
//TextView messages;
AutoLinkTextView messages;
//AutoLinkTextView autoLinkTextView;
TextView date_created;
TextView company;
public MyHolder(View convertView) {
super(convertView);
this.sms_image = (FeedImageView) convertView.findViewById(R.id.sms_image);
NetworkImageView thumbnail = (NetworkImageView) convertView.findViewById(R.id.thumbnail);
this.picture = (NetworkImageView) convertView.findViewById(R.id.picture);
//this.messages = (TextView) convertView.findViewById(R.id.messages);
this.messages = (AutoLinkTextView) convertView.findViewById(R.id.messages);
this.date_created = (TextView) convertView.findViewById(R.id.date_created);
this.company = (TextView) convertView.findViewById(R.id.company);
//TextView status = (TextView) convertView.findViewById(R.id.status);
}
}
}
正在显示的错误是
10-10 08:08:06.128 28368-28368/com.android.msahakyan.expandablenavigationdrawer E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.android.msahakyan.expandablenavigationdrawer, PID: 28368
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ComponentName.<init>(ComponentName.java:128)
at android.content.Intent.<init>(Intent.java:4666)
at com.android.msahakyan.expandablenavigationdrawer.adapter.FeedsListAdapter$1.onAutoLinkTextClick(FeedsListAdapter.java:87)
at com.luseen.autolinklibrary.AutoLinkTextView$1.onClick(AutoLinkTextView.java:77)
at android.text.method.LinkMovementMethod.onTouchEvent(LinkMovementMethod.java:217)
at com.luseen.autolinklibrary.LinkTouchMovementMethod.onTouchEvent(LinkTouchMovementMethod.java:38)
at android.widget.TextView.onTouchEvent(TextView.java:8689)
at android.view.View.dispatchTouchEvent(View.java:9787)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2686)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2335)
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2461)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1780)
at android.app.Activity.dispatchTouchEvent(Activity.java:2853)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:68)
at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2422)
at android.view.View.dispatchPointerEvent(View.java:10018)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4738)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4596)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4101)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4154)
at android.view
答案 0 :(得分:2)
您不应从RecyclerView适配器启动活动。相反,您需要创建一个侦听器,其中适配器所在的Activity / Fragment需要实现该侦听器。适配器应该只执行其工作,显示适配器的内容。
这样的事情:
public class FeedsListAdapter extends RecyclerView.Adapter<FeedsListAdapter.ViewHolder> {
// ...
/***** Creating OnItemClickListener *****/
// Define listener member variable
private OnItemClickListener listener;
// Define the listener interface
public interface OnItemClickListener {
void onAutoLinkTextClick(String companyId);
}
// Define the method that allows the parent activity or fragment to define the listener
public void setOnItemClickListener(OnItemClickListener listener) {
this.listener = listener;
}
public void onBindViewHolder(MyHolder holder, int position) {
...
holder.messages.setAutoLinkOnClickListener(new AutoLinkOnClickListener() {
@Override
public void onAutoLinkTextClick(AutoLinkMode autoLinkMode, String matchedText) {
listener.onAutoLinkTextClick(f.getCompanyId());
}
});
...
}
}
然后在Activity或Fragment上设置监听器:
FeedsListAdapter adapter = ...;
adapter.setOnItemClickListener(new ContactsAdapter.OnItemClickListener() {
@Override
public void onAutoLinkTextClick(String companyId) {
Intent intent = new Intent(activity, AboutUsActivity.class);
intent.putExtra("companyId", f.getCompanyId());
activity.startActivity(intent);
}
});