Android 开发Day4

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">
</LinearLayout>

• 接下来加入一个文本Testview和一个按钮Button

• <?xml version="1.0" encoding="utf-8"?>
  <LinearLayout 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"
      android:orientation="vertical"
      tools:context=".MainActivity">
      <TextView
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:text="学习安卓，你准备好了吗"
          android:id="@+id/tv_android"/>
      <Button
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:text="准备好了"
          android:id="@+id/bt_android"
          android:onClick="Welcome"/>
  </LinearLayout>