Merge pull request #526 from Xiaohuang-12/master

#3 #48 第3次实验

students/net1814080903216/activity_main.xml

@@ -0,0 +1,62 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".Net1814080903216MainActivity">
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Hello World!"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintLeft_toLeftOf="parent"
+        app:layout_constraintRight_toRightOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <Button
+        android:id="@+id/button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="228dp"
+        android:text="View"
+        app:layout_constraintBottom_toTopOf="@+id/textView"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.501"
+        app:layout_constraintStart_toStartOf="parent"
+        tools:ignore="MissingConstraints" />
+
+    <TextView
+        android:id="@+id/textview_01"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:drawableTop="@drawable/bg"
+        android:text="hello_world"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:ignore="MissingConstraints" />
+
+    <Button
+        android:id="@+id/button2"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="92dp"
+        android:text="About"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.52"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textView" />
+
+    <Button
+        android:id="@+id/button3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="31dp"
+        android:text="Setting"
+        app:layout_constraintBottom_toTopOf="@+id/textView"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>