[android] AlertDialog.Builder with custom layout and EditText; cannot access view

I am trying to create an alert dialog with an EditText object. I need to set the initial text of the EditText programmatically. Here's what I have.

AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
// ...Irrelevant code for customizing the buttons and title
AlertDialog alertDialog = dialogBuilder.create();
LayoutInflater inflater = this.getLayoutInflater();
alertDialog.setContentView(inflater.inflate(R.layout.alert_label_editor, null));
EditText editText = (EditText) findViewById(R.id.label_field);
editText.setText("test label");
alertDialog.show();

What do I need to change so that I can have a valid EditText object?

[edit]

So, it was pointed out by user370305 and others that I should be using alertDialog.findViewById(R.id.label_field);

Unfortunately there is another issue here. Apparently, setting the content view on the AlertDialog causes the program to crash at runtime. You have to set it on the builder.

AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
// ...Irrelevant code for customizing the buttons and title
dialogBuilder.setView(inflater.inflate(R.layout.alert_label_editor, null));
AlertDialog alertDialog = dialogBuilder.create();
LayoutInflater inflater = this.getLayoutInflater();
EditText editText = (EditText) alertDialog.findViewById(R.id.label_field);
editText.setText("test label");
alertDialog.show();

Unfortunately, when you do this, alertDialog.findViewById(R.id.label_field); now returns null.

[/edit]

Use this one

   AlertDialog.Builder builder = new AlertDialog.Builder(activity);
    // Get the layout inflater
    LayoutInflater inflater = (activity).getLayoutInflater();
    // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the
    // dialog layout
    builder.setTitle(title);
    builder.setCancelable(false);
    builder.setIcon(R.drawable.galleryalart);
    builder.setView(inflater.inflate(R.layout.dialogue, null))
    // Add action buttons
            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {

                    }
                }
            });
    builder.create();
    builder.show();

Change this:

EditText editText = (EditText) findViewById(R.id.label_field);

to this:

EditText editText = (EditText)  v.findViewById(R.id.label_field);

In case any one wants it in Kotlin :

val dialogBuilder = AlertDialog.Builder(this)
// ...Irrelevant code for customizing the buttons and title
val dialogView = layoutInflater.inflate(R.layout.alert_label_editor, null)
dialogBuilder.setView(dialogView)

val editText =  dialogView.findViewById(R.id.label_field)
editText.setText("test label")
val alertDialog = dialogBuilder.create()
alertDialog.show()

Reposted @user370305's answer.

View v=inflater.inflate(R.layout.alert_label_editor, null);
alertDialog.setContentView(v);
EditText editText = (EditText)v.findViewById(R.id.label_field);
editText.setText("test label");
alertDialog.show();

/**
 * Shows  confirmation dialog about signing in.
 */
private void startAuthDialog() {
    AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
    AlertDialog alertDialog = dialogBuilder.create();
    alertDialog.show();

    alertDialog.getWindow().setLayout(800, 1400);
    LayoutInflater inflater = this.getLayoutInflater();
    View dialogView = inflater.inflate(R.layout.auth_dialog, null);
    alertDialog.getWindow().setContentView(dialogView);
    EditText editText = (EditText) dialogView.findViewById(R.id.label_field);
    editText.setText("test label");
}

You can write:

AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);

 // ...Irrelevant code for customizing the buttons and title

LayoutInflater inflater = this.getLayoutInflater(); 

View dialogView= inflater.inflate(R.layout.alert_label_editor, null);                    
dialogBuilder.setView(dialogView);

Button button = (Button)dialogView.findViewById(R.id.btnName);

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

         //Commond here......

       }
   });

EditText editText = (EditText)
dialogView.findViewById(R.id.label_field); 

editText.setText("test label"); 

dialogBuilder.create().show();