How to make dialog that accesses a view without using setContentView

I am creating a dialog with an EditText, and I need to get this value in another activity, without using the setContentView because I do not want to redirect to the xml of the dialog ... The following code:

dialog_edittext.xml:

<?xml version="1.0" encoding="utf-8"?>

<HorizontalScrollView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/valorml"
            android:textColor="@color/primary_text"
            android:textSize="15dp"
            android:id="@+id/digite"/>
        <EditText
            android:layout_width="80dp"
            android:layout_height="wrap_content"
            android:id="@+id/mlvalor"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/ml"
            android:textSize="15dp"
            android:textColor="@color/primary_text"
            android:id="@+id/ml"/>
    </LinearLayout>
</HorizontalScrollView>

<Button
    android:layout_width="wrap_content"
    android:layout_height="30dp"
    android:text="@string/btn_add"
    android:background="@drawable/designbotao"
    android:textColor="@color/icons"
    android:layout_marginBottom="5dp"
    android:layout_marginTop="5dp"
    android:id="@+id/btn_addcopo"/>

When I try to get the value typed in the dialog's edittext:

 /*Está dentro do onCreate de HomeActivity.java*/
    mloutro.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String titulo2 = "ADICIONAR COPO";
            LayoutInflater inflater2 = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View v2 = inflater2.inflate(R.layout.dialogo_edittext, null);
            dialog2 = new Dialog(HomeActivity.this);
            dialog2.setTitle(titulo2);
            dialog2.setContentView(v2);
            dialog2.show();
            /*Botão do dialog*/
            Button add = (Button) findViewById(R.id.btn_addcopo);

            add.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    /*valor digitado no EditText*/
                    EditText valorml = (EditText) findViewById(R.id.mlvalor);
                    int valml = Integer.parseInt(valorml.getText().toString());
                    barraprogresso.setProgress(barraprogresso.getProgress() + valml);
                    falta_agua -= valml;
                    Log.i("outro", "falta: " + falta_agua + "qtd agua:" + qtd_agua);
                    dialog2.hide();
                    if (falta_agua <= 0) {
                        nivelU++;
                        String texto = getString(R.string.lvl);
                        Log.i("texto", "texto: " + texto);
                        nivel.setText(getString(R.string.lvl) + " " + nivelU);
                        barraprogresso.setProgress(0);
                        falta_agua = qtd_agua;
                        dialog.show();
                    }
                }
            });
        }
    });

When I click the button inside the dialog I need to get the value of edittext and use it in my main activty (HomeActivity). I tried to use the setContentView but it redirects to the xml of the dialog and does not happen when I click on Add. Without the error setContentView ...: (