CardView binded to worker class returns null





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I Have the followin CardView



 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/coordinatorLayout">


<fragment
android:id="@+id/mapActivity"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Map.MyMap" />

<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:visibility="gone"
android:id="@+id/cardViewData"
android:backgroundTint="@color/colorPrimary"
app:cardCornerRadius="8dp">
...


Now, I call this CardView in my Activity the this way to get the id of it and pass that CardView to a worker class to handle some logic there with it (I just need to set it visible )



private CardView mCardViewData;


inside onCreate() , after setContentView



 mCardViewData = findViewById(R.id.cardViewData);
new MapsUtils(this,mCardViewData);


As you can see , Im sending this cardview to the worker class where I get it as follow



private CardView mCardViewData;

public MapsUtils(Context context,CardView cardView{

this.mCardViewData = cardView;
this.mContext = context;

}


And then Im using it inside MapsUtil in a method like this



 private void initRun(){
mCardViewData.setVisibility(View.VISIBLE);

}


I need to have this cardview binded to my worker class because I manage the logic of the map in a worker class and not in the view.



Now, what I'm getting is this




java.lang.NullPointerException: Attempt to invoke virtual method
'void androidx.cardview.widget.CardView.setVisibility(int)' on a null
object reference
at com.utils.MapsUtils.initRun(MapsUtils.java:182)
at com.utils.MapsUtils.access$000(MapsUtils.java:62)
at com.utils.MapsUtils$2.onClick(MapsUtils.java:219)




Error points here



mCardViewData.setVisibility(View.VISIBLE);



And Im trying to see where Im wrong because I just defined all I need to work with that CardView in my worker class










share|improve this question























  • i think so you should add android.support.v7.widget.CardView instead of androidx.cardview.widget.CardView in XML

    – Ali Ahmed
    Nov 23 '18 at 12:48











  • I'm using androidx libraries, it works the same

    – Todd
    Nov 23 '18 at 12:49











  • make sure you're caling initRun() after initializing CardView. error says your CardView is not initialized , so its NULL

    – Ali Ahmed
    Nov 23 '18 at 12:51













  • hmm let me see.

    – Todd
    Nov 23 '18 at 12:52











  • yes, Im initializing it after that

    – Todd
    Nov 23 '18 at 12:52


















0















I Have the followin CardView



 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/coordinatorLayout">


<fragment
android:id="@+id/mapActivity"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Map.MyMap" />

<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:visibility="gone"
android:id="@+id/cardViewData"
android:backgroundTint="@color/colorPrimary"
app:cardCornerRadius="8dp">
...


Now, I call this CardView in my Activity the this way to get the id of it and pass that CardView to a worker class to handle some logic there with it (I just need to set it visible )



private CardView mCardViewData;


inside onCreate() , after setContentView



 mCardViewData = findViewById(R.id.cardViewData);
new MapsUtils(this,mCardViewData);


As you can see , Im sending this cardview to the worker class where I get it as follow



private CardView mCardViewData;

public MapsUtils(Context context,CardView cardView{

this.mCardViewData = cardView;
this.mContext = context;

}


And then Im using it inside MapsUtil in a method like this



 private void initRun(){
mCardViewData.setVisibility(View.VISIBLE);

}


I need to have this cardview binded to my worker class because I manage the logic of the map in a worker class and not in the view.



Now, what I'm getting is this




java.lang.NullPointerException: Attempt to invoke virtual method
'void androidx.cardview.widget.CardView.setVisibility(int)' on a null
object reference
at com.utils.MapsUtils.initRun(MapsUtils.java:182)
at com.utils.MapsUtils.access$000(MapsUtils.java:62)
at com.utils.MapsUtils$2.onClick(MapsUtils.java:219)




Error points here



mCardViewData.setVisibility(View.VISIBLE);



And Im trying to see where Im wrong because I just defined all I need to work with that CardView in my worker class










share|improve this question























  • i think so you should add android.support.v7.widget.CardView instead of androidx.cardview.widget.CardView in XML

    – Ali Ahmed
    Nov 23 '18 at 12:48











  • I'm using androidx libraries, it works the same

    – Todd
    Nov 23 '18 at 12:49











  • make sure you're caling initRun() after initializing CardView. error says your CardView is not initialized , so its NULL

    – Ali Ahmed
    Nov 23 '18 at 12:51













  • hmm let me see.

    – Todd
    Nov 23 '18 at 12:52











  • yes, Im initializing it after that

    – Todd
    Nov 23 '18 at 12:52














0












0








0








I Have the followin CardView



 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/coordinatorLayout">


<fragment
android:id="@+id/mapActivity"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Map.MyMap" />

<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:visibility="gone"
android:id="@+id/cardViewData"
android:backgroundTint="@color/colorPrimary"
app:cardCornerRadius="8dp">
...


Now, I call this CardView in my Activity the this way to get the id of it and pass that CardView to a worker class to handle some logic there with it (I just need to set it visible )



private CardView mCardViewData;


inside onCreate() , after setContentView



 mCardViewData = findViewById(R.id.cardViewData);
new MapsUtils(this,mCardViewData);


As you can see , Im sending this cardview to the worker class where I get it as follow



private CardView mCardViewData;

public MapsUtils(Context context,CardView cardView{

this.mCardViewData = cardView;
this.mContext = context;

}


And then Im using it inside MapsUtil in a method like this



 private void initRun(){
mCardViewData.setVisibility(View.VISIBLE);

}


I need to have this cardview binded to my worker class because I manage the logic of the map in a worker class and not in the view.



Now, what I'm getting is this




java.lang.NullPointerException: Attempt to invoke virtual method
'void androidx.cardview.widget.CardView.setVisibility(int)' on a null
object reference
at com.utils.MapsUtils.initRun(MapsUtils.java:182)
at com.utils.MapsUtils.access$000(MapsUtils.java:62)
at com.utils.MapsUtils$2.onClick(MapsUtils.java:219)




Error points here



mCardViewData.setVisibility(View.VISIBLE);



And Im trying to see where Im wrong because I just defined all I need to work with that CardView in my worker class










share|improve this question














I Have the followin CardView



 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/coordinatorLayout">


<fragment
android:id="@+id/mapActivity"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Map.MyMap" />

<androidx.cardview.widget.CardView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:visibility="gone"
android:id="@+id/cardViewData"
android:backgroundTint="@color/colorPrimary"
app:cardCornerRadius="8dp">
...


Now, I call this CardView in my Activity the this way to get the id of it and pass that CardView to a worker class to handle some logic there with it (I just need to set it visible )



private CardView mCardViewData;


inside onCreate() , after setContentView



 mCardViewData = findViewById(R.id.cardViewData);
new MapsUtils(this,mCardViewData);


As you can see , Im sending this cardview to the worker class where I get it as follow



private CardView mCardViewData;

public MapsUtils(Context context,CardView cardView{

this.mCardViewData = cardView;
this.mContext = context;

}


And then Im using it inside MapsUtil in a method like this



 private void initRun(){
mCardViewData.setVisibility(View.VISIBLE);

}


I need to have this cardview binded to my worker class because I manage the logic of the map in a worker class and not in the view.



Now, what I'm getting is this




java.lang.NullPointerException: Attempt to invoke virtual method
'void androidx.cardview.widget.CardView.setVisibility(int)' on a null
object reference
at com.utils.MapsUtils.initRun(MapsUtils.java:182)
at com.utils.MapsUtils.access$000(MapsUtils.java:62)
at com.utils.MapsUtils$2.onClick(MapsUtils.java:219)




Error points here



mCardViewData.setVisibility(View.VISIBLE);



And Im trying to see where Im wrong because I just defined all I need to work with that CardView in my worker class







java android cardview






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 23 '18 at 12:40









ToddTodd

10412




10412













  • i think so you should add android.support.v7.widget.CardView instead of androidx.cardview.widget.CardView in XML

    – Ali Ahmed
    Nov 23 '18 at 12:48











  • I'm using androidx libraries, it works the same

    – Todd
    Nov 23 '18 at 12:49











  • make sure you're caling initRun() after initializing CardView. error says your CardView is not initialized , so its NULL

    – Ali Ahmed
    Nov 23 '18 at 12:51













  • hmm let me see.

    – Todd
    Nov 23 '18 at 12:52











  • yes, Im initializing it after that

    – Todd
    Nov 23 '18 at 12:52



















  • i think so you should add android.support.v7.widget.CardView instead of androidx.cardview.widget.CardView in XML

    – Ali Ahmed
    Nov 23 '18 at 12:48











  • I'm using androidx libraries, it works the same

    – Todd
    Nov 23 '18 at 12:49











  • make sure you're caling initRun() after initializing CardView. error says your CardView is not initialized , so its NULL

    – Ali Ahmed
    Nov 23 '18 at 12:51













  • hmm let me see.

    – Todd
    Nov 23 '18 at 12:52











  • yes, Im initializing it after that

    – Todd
    Nov 23 '18 at 12:52

















i think so you should add android.support.v7.widget.CardView instead of androidx.cardview.widget.CardView in XML

– Ali Ahmed
Nov 23 '18 at 12:48





i think so you should add android.support.v7.widget.CardView instead of androidx.cardview.widget.CardView in XML

– Ali Ahmed
Nov 23 '18 at 12:48













I'm using androidx libraries, it works the same

– Todd
Nov 23 '18 at 12:49





I'm using androidx libraries, it works the same

– Todd
Nov 23 '18 at 12:49













make sure you're caling initRun() after initializing CardView. error says your CardView is not initialized , so its NULL

– Ali Ahmed
Nov 23 '18 at 12:51







make sure you're caling initRun() after initializing CardView. error says your CardView is not initialized , so its NULL

– Ali Ahmed
Nov 23 '18 at 12:51















hmm let me see.

– Todd
Nov 23 '18 at 12:52





hmm let me see.

– Todd
Nov 23 '18 at 12:52













yes, Im initializing it after that

– Todd
Nov 23 '18 at 12:52





yes, Im initializing it after that

– Todd
Nov 23 '18 at 12:52












1 Answer
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Ok, I found the problem, the problem was that since Im using multiple constructors, the constructor that init a method that calls for the CardView was initializing it without all the elements I needed, now I binded all my elements to that constructor and its working






share|improve this answer
























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    Ok, I found the problem, the problem was that since Im using multiple constructors, the constructor that init a method that calls for the CardView was initializing it without all the elements I needed, now I binded all my elements to that constructor and its working






    share|improve this answer




























      0














      Ok, I found the problem, the problem was that since Im using multiple constructors, the constructor that init a method that calls for the CardView was initializing it without all the elements I needed, now I binded all my elements to that constructor and its working






      share|improve this answer


























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        0







        Ok, I found the problem, the problem was that since Im using multiple constructors, the constructor that init a method that calls for the CardView was initializing it without all the elements I needed, now I binded all my elements to that constructor and its working






        share|improve this answer













        Ok, I found the problem, the problem was that since Im using multiple constructors, the constructor that init a method that calls for the CardView was initializing it without all the elements I needed, now I binded all my elements to that constructor and its working







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 23 '18 at 12:56









        ToddTodd

        10412




        10412
































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