Codice

package it.fontanagianpaolo.www.primoluglio2015;

import android.app.Dialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends AppCompatActivity {

    //EditText editText;

public static final String pref="esempiopref";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bottone1 = (Button) findViewById(R.id.bottone1);
        Button bottone2 = (Button) findViewById(R.id.bottone2);
        Button bottone3 = (Button) findViewById(R.id.bottone3);
        Button bottone4 = (Button) findViewById(R.id.bottone4);


        bottone1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent menu1 = new Intent(getApplicationContext(), menu1.class);
                startActivity(menu1);
            }
        });
        bottone2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent menu2 = new Intent(getApplicationContext(), menu2.class);
                startActivity(menu2);
            }
        });

        bottone3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                final Dialog dialog = new Dialog(MainActivity.this);
                dialog.setTitle("Password Dialog");
                dialog.setContentView(R.layout.custom_dialog_layout);
                dialog.show();
                final EditText password = (EditText) dialog.findViewById(R.id.editText2);
                Button accedi = (Button) dialog.findViewById(R.id.accedi);
                Button indietro = (Button) dialog.findViewById(R.id.indietro);
                accedi.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {

                        String ps = password.getText().toString();

                        if (ps.equals("pass")) {


                            Intent i = new Intent(getApplicationContext(), menu3.class);
                            startActivity(i);
                        } else {
                            Toast.makeText(getApplicationContext(), "Non hai l'autorizzazione a procedere", Toast.LENGTH_LONG).show();
                        }
                    }
                });
                indietro.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                        Intent indietro = new Intent(getApplicationContext(), MainActivity.class);
                        startActivity(indietro);
                    }
                });

               /* Intent menu3=new Intent(MainActivity.this, Password.class);
                startActivity(menu3);

                */


                /*Toast toast = Toast.makeText(MainActivity.this, "Non sei abilitato alla visualizzazione", Toast.LENGTH_LONG);
                toast.show();*/
                /*Intent menu3=new Intent(getApplicationContext(), menu3.class);
                startActivity(menu3);*/
            }


        }); //fine setonclicklistener di button  3
        bottone4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent menu4 = new Intent(getApplicationContext(), menu4.class);
                startActivity(menu4);
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}