Android : share button in custom listview doesn't work

I'm following share a text with button in custom listview but it doesn't work . this is code for OnClick in ListViewAdapter.java :

OnClickListener clickListener = new OnClickListener() {

            @Override
            public void onClick(View v) {
                try{
                    Context context = v.getContext();
                    String ab = (String) holder.tvComment.getText();
                    holder.tvComment.setText(ab);

                    Toast.makeText(context, ab, Toast.LENGTH_LONG).show();
                    Intent sendIntent = new Intent();
                    sendIntent.setAction(Intent.ACTION_SEND);

                    sendIntent.putExtra(Intent.EXTRA_TEXT, ab);
                    sendIntent.setType("text/plain");


                    context.startActivity(sendIntent);

                }
                catch (Exception e){
                Log.w("Share Data", "Error!");
                }

            }
        };


        holder.sharebtn.setOnClickListener(clickListener);