How to start Activity in adapter?

Just pass in the current Context to the Adapter constructor and store it as a field. Then inside the onClick you can use that context to call startActivity().

pseudo-code

public class MyAdapter extends Adapter {     private Context context;     public MyAdapter(Context context) {          this.context = context;          }     public View getView(...){         View v;         v.setOnClickListener(new OnClickListener() {             void onClick() {                 context.startActivity(...);             }         });     }}

When implementing the onClickListener, you can use v.getContext.startActivity.

btn.setOnClickListener(new OnClickListener() {                      @Override    public void onClick(View v) {        v.getContext().startActivity(PUT_YOUR_INTENT_HERE);    }});

public class MyAdapter extends Adapter {     private Context context;           public MyAdapter(Context context) {          this.context = context;              }     public View getView(...){           View v;           v.setOnClickListener(new OnClickListener() {             void onClick() {                  Intent intent= new Intent(context, ToActivity.class);                    intent.putExtra("your_extra","your_class_value");                 context.startActivity(intent);             }         });     }}