App crashing while setting up click listener on button in dialog…

Question

Build a dialog I'd like add a listener, but the app crashes.What is wrong?

private void Info(){

        textview = (TextView) findViewById(R.id.textView1);

        LayoutInflater li = LayoutInflater.from(this);
        View view = li.inflate(R.layout.info, null);

        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setView(view).create().show();

        buttonInfo = (Button)findViewById(R.id.buttonInfo);

        buttonInfo.setOnClickListener(new View.OnClickListener() {
              public void onClick(View view) { 

              }
            });

Answer 1

replace

 buttonInfo = (Button) view.findViewById(R.id.buttonInfo);

by

buttonInfo = (Button) findViewById(R.id.buttonInfo);

final code

private void Info(){

        textview = (TextView) findViewById(R.id.textView1);

        LayoutInflater li = LayoutInflater.from(this);
        View view = li.inflate(R.layout.info, null);

        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setView(view).create().show();

        buttonInfo = (Button) view.findViewById(R.id.buttonInfo);

        buttonInfo.setOnClickListener(new View.OnClickListener() {
              public void onClick(View view) { 

              }
            });

Answer 2

I guess that the button is inside your dialog's layout.

If it's the case, try to replace

buttonInfo = (Button)findViewById(R.id.buttonInfo);

by

buttonInfo = (Button) view.findViewById(R.id.buttonInfo);

And you need to store the created AlertDialog (instead of the Builder) if you want to dismiss it after:

    final AlertDialog dialog = new AlertDialog.Builder(this).setView(view).show();

    buttonInfo = (Button) findViewById(R.id.buttonInfo);

    buttonInfo.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            dialog.dismiss();
        }
    });