Не могу разобраться в этом Исключении с нулевой точкой
https://stackoverflow.com//questions/20021588
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Я добавляю прослушиватель onClick в текстовое поле в моем адаптере.Я просто хочу, чтобы текст в этом поле был отправлен в мое поле ввода текста (edittext1).Я пытаюсь использовать приведенный ниже код, однако он выдает мне исключение с нулевой точкой в строке, указывающей на edttext1.Помогите, пожалуйста
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
LayoutInflater inflater2 = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater2.inflate(R.layout.activity_discuss, parent, false);
if (row == null) {
LayoutInflater inflater = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if(type==1 || type==3)
row = inflater.inflate(R.layout.listitem_discuss, parent, false);
else if(type==4 || type==5)
row = inflater.inflate(R.layout.listitem_users, parent, false);
else
row = inflater.inflate(R.layout.listitem_messages, parent, false);
}
//
final OneComment coment = getItem(position);
userComment = (TextView) row.findViewById(R.id.comment);
userImage = (ImageView) row.findViewById(R.id.place_img);
userName = (TextView) row.findViewById(R.id.place_name);
userOnlineImage = (ImageView) row.findViewById(R.id.pe_profile_pic);
commentDate = (TextView) row.findViewById(R.id.place_distance);
msgPic = (ImageView) row.findViewById(R.id.msgPic);
userComment.setText(coment.comment);
editText1 = (EditText) row.findViewById(R.id.cr_room_name);
userName.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
editText1.setText("testing");
Log.v("response","username selected");
// TODO Auto-generated method stub
}
});
На самом деле я бы предпочел сделать это длинным щелчком мыши.Есть ли разница в настройке?
Трассировка стека
11-16 12:46:29.100: E/AndroidRuntime(8047): FATAL EXCEPTION: main
11-16 12:46:29.100: E/AndroidRuntime(8047): java.lang.NullPointerException
11-16 12:46:29.100: E/AndroidRuntime(8047): at com.peekatucorp.peekatu.DiscussArrayAdapter$1.onClick(DiscussArrayAdapter.java:129)
11-16 12:46:29.100: E/AndroidRuntime(8047): at android.view.View.performClick(View.java:4240)
11-16 12:46:29.100: E/AndroidRuntime(8047): at android.view.View$PerformClick.run(View.java:17721)
11-16 12:46:29.100: E/AndroidRuntime(8047): at android.os.Handler.handleCallback(Handler.java:730)
11-16 12:46:29.100: E/AndroidRuntime(8047): at android.os.Handler.dispatchMessage(Handler.java:92)
11-16 12:46:29.100: E/AndroidRuntime(8047): at android.os.Looper.loop(Looper.java:137)
11-16 12:46:29.100: E/AndroidRuntime(8047): at android.app.ActivityThread.main(ActivityThread.java:5103)
11-16 12:46:29.100: E/AndroidRuntime(8047): at java.lang.reflect.Method.invokeNative(Native Method)
11-16 12:46:29.100: E/AndroidRuntime(8047): at java.lang.reflect.Method.invoke(Method.java:525)
11-16 12:46:29.100: E/AndroidRuntime(8047): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
11-16 12:46:29.100: E/AndroidRuntime(8047): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
11-16 12:46:29.100: E/AndroidRuntime(8047): at dalvik.system.NativeStart.main(Native Method)
Actvity_discuss.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/form"
android:layout_alignParentTop="true"
android:choiceMode="none"
android:divider="#00000000"
android:dividerHeight="@dimen/zerosize"
android:footerDividersEnabled="false"
android:headerDividersEnabled="false"
android:listSelector="@android:color/transparent">
</ListView>
<RelativeLayout
android:id="@+id/form"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="40dp"
android:background="@drawable/inputbg" >
<!-- <Button
android:id="@+id/postpic"
android:layout_width="30dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:background="@drawable/attachbtn" /> -->
<!-- android:background="@drawable/sendbutton" -->
<EditText
android:id="@+id/cr_room_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/sendMessage"
android:layout_weight="3"
android:ems="10"
android:hint="Enter Message"
android:inputType="text" />
<ImageView
android:id="@+id/postpic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:src="@drawable/picattach" />
<Button
android:id="@+id/sendMessage"
style="@style/SingleGradient"
android:layout_width="35dp"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
Решение
Кажется, возникла небольшая путаница :вы просите найти editText1 под идентификатором cr_room_name :внутри listitem_messages.xml, но в настоящее время он находится внутри Actvity_discuss.xml.
Activity activity = (Activity) getContext();
editText1 = (EditText) activity.findViewById(R.id.cr_room_name);
Но даже если это сработает, это действительно уродливый способ связать представление и действие, вам лучше выбрать шаблон проектирования, доступный наблюдателю.
Другие советы
static class ViewHolder {
TextView textView;
TextView timeView;
ImageView imageView;
View divider;
ImageButton but;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
appPrefs = new AppPreferences(context.getApplicationContext());
final ViewHolder holder;
final UserModel s = (UserModel) values.get(position);
if (convertView == null) {
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.list_user_item, parent, false);
holder.textView = (TextView) convertView.findViewById(R.id.label);
holder.timeView = (TextView) convertView.findViewById(R.id.list_time);
holder.imageView = (ImageView) convertView.findViewById(R.id.imageView1);
holder.divider = (View) convertView.findViewById(R.id.side_divider);
holder.but = (ImageButton) convertView.findViewById(R.id.details_list_button);
convertView.setTag(holder);
}
else
{holder = (ViewHolder) convertView.getTag();}
holder.timeView.setText(s.getTimePosted());
holder.textView.setText(s.getTitle());
return convertView;
}
Вот пример работы GetView для вас, чтобы посмотреть на
Without logcat information it will be harder to tell but i am just guessing, can you make sure cr_room_name is actually in the activity_discuss.xml file. If it is in the activity_discuss layout file, then only after seeing the logcat we can figure out what might be the problem.
After seeing you stacktrace there is only one thing coming to my mind. Please make sure all of those view id's are in it's respective layout file.
As i can see from your layout and code, there is no place_name textview in your Actvity_discuss.xml file.
Since you are using different layout for different purposes make sure you do some null checking before actually referencing the view from getView and specially when you are setting a listener for a particular view.
Nullpoint is an easy problem to solve, sometimes because an object is not initialized, and you should debug to find out why. Many times the object is null, causing problems
