Here is an example of a login UI design using XML code in Android:

 Here is an example of a login UI design using XML code in Android:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">

    <ImageView
        android:id="@+id/logo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/logo"
        android:layout_marginTop="30dp"
        android:layout_gravity="center" />

    <EditText
        android:id="@+id/username"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Username"
        android:inputType="text"
        android:layout_margin="15dp"
        android:padding="10dp" />

    <EditText
        android:id="@+id/password"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Password"
        android:inputType="textPassword"
        android:layout_margin="15dp"
        android:padding="10dp" />

    <Button
        android:id="@+id/login_button"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="LOGIN"
        android:layout_margin="15dp"
        android:padding="10dp" />

</LinearLayout>

This code creates a login UI with an ImageView for a logo, two EditText fields for the username and password, and a button for logging in. It uses a LinearLayout with vertical orientation to organize the elements on the screen. It's important to notice that this is a basic example, you should use other elements or libraries to make a secure login, like a password input type and a encryption system to protect the user's data.