activity_main.xml

<?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:background="#d8e0e8"
    android:orientation="vertical">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="horizontal">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/textView3"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="登录" />
            </LinearLayout>
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:orientation="horizontal">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <TextView
                            android:id="@+id/textView8"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:text="账号：" />
                    </LinearLayout>

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <EditText
                            android:id="@+id/username"
                            android:layout_width="wrap_content"
                            android:layout_height="match_parent"
                            android:layout_weight="1"
                            android:ems="10"
                            android:inputType="textPersonName"
                            android:text="" />
                    </LinearLayout>
                </LinearLayout>
            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:orientation="horizontal">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <TextView
                            android:id="@+id/textView9"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="密码:" />
                    </LinearLayout>

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <EditText
                            android:id="@+id/password"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:ems="10"
                            android:inputType="textPassword" />
                    </LinearLayout>
                </LinearLayout>
            </LinearLayout>
        </LinearLayout>


        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"

            android:orientation="horizontal">

            <Button

                android:id="@+id/button1"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:text="登录" />


            <Button

                android:id="@+id/button2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="注册" />

        </LinearLayout>

    </LinearLayout>


</LinearLayout>

activity_main2.xml

<?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:background="#d8e0e8"
    android:orientation="vertical">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:orientation="horizontal">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/textView3"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="注册" />
            </LinearLayout>
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:orientation="horizontal">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <TextView
                            android:id="@+id/textView8"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:text="账号：" />
                    </LinearLayout>

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <EditText
                            android:id="@+id/username"
                            android:layout_width="wrap_content"
                            android:layout_height="match_parent"
                            android:layout_weight="1"
                            android:ems="10"
                            android:inputType="textPersonName"
                            android:text="" />
                    </LinearLayout>
                </LinearLayout>
            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:orientation="horizontal">

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <TextView
                            android:id="@+id/textView9"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="密码:" />
                    </LinearLayout>

                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="match_parent"
                        android:gravity="center"
                        android:orientation="horizontal">

                        <EditText
                            android:id="@+id/password"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:ems="10"
                            android:inputType="textPassword" />
                    </LinearLayout>
                </LinearLayout>
            </LinearLayout>
        </LinearLayout>


        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"

            android:orientation="horizontal">

            <Button

                android:id="@+id/button3"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:text="空白按钮" />


            <Button

                android:id="@+id/button4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="返回" />

        </LinearLayout>

    </LinearLayout>


</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapplication">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApplication">
        <activity
            android:name=".MainActivity2"
            android:exported="false" />
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

在结尾说一下建文件的方法

新建Activity.java

在layout里新建xml布局文件