Call Activity method from adapter

Question

Is it possible to call method that is defined in Activity from ListAdapter    I want to make a Button in list s row and when this button is clicked  it should perform the method  that is defined in corresponding Activity  I tried to set onClickListener in my ListAdapter but I don t know how to call this method  what s its path       when I used Activity this method   I get the following error   No enclosing instance of the type Activity is accessible in scope   Any Idea

User · Answer

For Kotlin    In your adapter  simply call    context as Your Activity Name  yourMethod

User · Answer

Yes you can   In the adapter Add a new Field    private Context mContext    In the adapter Constructor add the following code     public AdapterName         Context context        your code    this mContext   context      In the getView      of Adapter    Button btn    Button  convertView findViewById yourButtonId   btn setOnClickListener new Button OnClickListener        Override   public void onClick View v        if  mContext instanceof YourActivityName            YourActivityName mContext  yourDesiredMethod                    replace with your own class names where you see your code  your activity etc   If you need  to use this same adapter for more than  one activity then     Create an Interface  public interface IMethodCaller       void yourDesiredMethod        Implement this interface in activities you require to have this method calling functionality   Then in Adapter getView    call like    Button btn    Button  convertView findViewById yourButtonId   btn setOnClickListener new Button OnClickListener          Override     public void onClick View v            if  mContext instanceof IMethodCaller                  IMethodCaller  mContext  yourDesiredMethod                          You are done  If you need to use this adapter for activities which does not require this calling mechanism  the code will not execute  If check fails

User · Answer

One more way is    Write a method in your adapter lets say  public void callBack       Now while creating an object for adapter in activity override this method  Override method will be called when you call the method in adapter   Myadapter adapter   new Myadapter        Override   public void callBack            dosomething

User · Answer

if  parent getContext   instanceof yourActivity        execute code     this condition will enable you to execute something if the Activity which has the GroupView that requesting views from the getView   method of your adapter is yourActivity  NOTE   parent is that GroupView

User · Answer

Original  I understand the current answer but needed a more clear example  Here is an example of what I used with an Adapter RecyclerView Adapter  and an Activity  In your Activity  This will implement the interface that we have in our Adapter  In this example  it will be called when the user clicks on an item in the RecyclerView  public class MyActivity extends Activity implements AdapterCallback        private MyAdapter myAdapter        Override     public void onMethodCallback               do something             Override     protected void onCreate  Nullable Bundle savedInstanceState            super onCreate savedInstanceState            myAdapter   new MyAdapter this            In your Adapter  In the Activity  we initiated our Adapter and passed this as an argument to the constructer  This will initiate our interface for our callback method  You can see that we use our callback method for user clicks  public class MyAdapter extends RecyclerView Adapter lt MyAdapter ViewHolder gt         private AdapterCallback adapterCallback       public MyAdapter Context context            try               adapterCallback     AdapterCallback  context             catch  ClassCastException e                throw new ClassCastException  quot Activity must implement AdapterCallback  quot   e                         Override     public void onBindViewHolder MyAdapter ViewHolder viewHolder  int position               simple example  call interface here            not complete         viewHolder itemView setOnClickListener new OnClickListener                  Override             public void onClick View view                    try                       adapterCallback onMethodCallback                      catch  ClassCastException e                          do something                                                        public static interface AdapterCallback           void onMethodCallback

User · Answer

Basic and simple   In your adapter simply use this     YourParentClass  context  functionToRun

User · Answer

You can do it this way  Declare interface  public interface MyInterface      public void foo       Let your Activity imlement it      public class MyActivity extends Activity implements MyInterface          public void foo                  do stuff                            public onCreate                  your code             MyAdapter adapter   new MyAdapter this     this will work as your                                                         MyInterface listener                  Then pass your activity to ListAdater  public MyAdapter extends BaseAdater      private MyInterface listener       public MyAdapter MyInterface listener           this listener   listener           And somewhere in adapter  when you need to call that Activity method  listener foo

User · Answer

In Kotlin there is now a cleaner way by using lambda functions  no need for interfaces   class MyAdapter val adapterOnClick   Any  - gt  Unit        fun setItem item  Any            myButton setOnClickListener   adapterOnClick item             class MyActivity       override fun onCreate savedInstanceState  Bundle             var myAdapter   MyAdapter   item - gt  doOnClick item                fun doOnClick item  Any

[android] Call Activity method from adapter

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