从对话框android获取文本

Question

执行showDialog方法后，String s的值保持不变，并且不会因editText的输入而改变

谁能告诉我为什么？

String s ="";

public void showDialog(String text) {

    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
    final LayoutInflater inflater = this.getLayoutInflater();

    builder.setView(inflater.inflate(R.layout.dialouge, null))
            .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    Dialog f = (Dialog) dialog;
                    EditText editText = f.findViewById(R.id.markers_name);
                    s=editText.getText().toString();

                }
            })
            .setNegativeButton("cancel", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    dialog.cancel();
                }
            });

    builder.show();
}