Android基础-约束布局(ConstraintLayout)红包界面

约束布局是可以进行拖动的布局类型

约束布局的属性

1. 相当于相对布局的alignLeft左边线对齐 

app:layout_constraintBottom_toBottomOf="parent" 相当于RelativeLayout的alignLeft
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf 同Left_toLeftof
app:layout_constraintEnd_toEndOf 同Right_toRightof

2.在某某物体的左边右边上边下边 

 app:layout_constraintLeft_toRightOf  相当于RetiveLayout的toRightOf
 app:layout_constraintRight_toLeftOf 相当于RetiveLayout的toLeftOf
 app:layout_constraintTop_toBottomOf 相当于RetiveLayout的below
 app:layout_constraintBottom_toTopmOf 相当于RetiveLayout的above
 app:layout_constraintStart_toEndOf 同Left_toRightOf
 app:layout_constraintEnd_toStartOf 同Left_toLeftOf

3.相当于上下控件或者左右控件的距离 

  app:layout_constraintVertical_bias="0.4" 垂直距离
  app:layout_constraintHorizontal_bias="0.4" 水平距离

<?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=".MainActivity"
    android:background="#ff0000">

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"

        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:text="红包"
        android:textColor="#f6d5a8"
        android:textSize="22sp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:layout_marginLeft="8dp"
        android:text="&lt; 返回"
        android:textColor="#f6d5a8"
        android:textSize="22sp"
        app:layout_constraintLeft_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:layout_editor_absoluteX="5dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="15dp"
        android:layout_marginRight="8dp"
        android:text="红包记录"
        android:textColor="#f6d5a8"
        android:textSize="22sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button"
        android:layout_width="330dp"
        android:layout_height="60dp"
        android:background="#FFA000"
        android:text="一字千金红包"
        app:backgroundTint="#FBB506"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.53" />

    <Button
        android:layout_width="330dp"
        android:layout_height="60dp"
        android:layout_marginBottom="15dp"
        app:backgroundTint="#FBB506"
        android:id="@+id/button2"
        android:background="#FFA000"
        android:text="普通红包"
        app:layout_constraintBottom_toTopOf="@+id/button"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:layout_width="330dp"
        android:layout_height="60dp"
        android:layout_marginBottom="15dp"
        app:backgroundTint="#FBB506"
        android:id="@+id/button3"
        android:background="#FFA000"
        android:text="口令红包"
        app:layout_constraintBottom_toTopOf="@+id/button2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <LinearLayout
        android:id="@+id/linearLayout"
        android:layout_width="330dp"
        android:layout_height="60dp"
        android:background="@mipmap/border"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button"
        app:layout_constraintVertical_bias="0.4">

        <EditText
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@null"
            android:gravity="center"
            android:hint="输口令,领红包" />

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="确定"
            android:textColor="#cccccc"
            android:textSize="26sp" />

    </LinearLayout>

    <!--
    app:layout_constraint方位_to方位of="?"
    ?:1.parent 2.引用其他控件id
    当前控件的某个方位和另一个参照物的某个方位对齐
        app:layout_constraintBottom_toBottomOf="parent" 相当于RelativeLayout的alignLeft
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf 同Left_toLeftof
        app:layout_constraintEnd_toEndOf 同Right_toRightof

        当前控件的A侧会在参照物的B侧
        app:layout_constraintLeft_toRightOf  相当于RetiveLayout的toRightOf
        app:layout_constraintRight_toLeftOf 相当于RetiveLayout的toLeftOf
        app:layout_constraintTop_toBottomOf 相当于RetiveLayout的below
        app:layout_constraintBottom_toTopmOf 相当于RetiveLayout的above
        app:layout_constraintStart_toEndOf 同Left_toRightOf
        app:layout_constraintEnd_toStartOf 同Left_toLeftOf

        app:layout_constraintVertical_bias="0.4" 垂直距离
        app:layout_constraintHorizontal_bias="0.4" 水平距离

    -->


    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="口令红包规则"
        android:textColor="#f6d5a8"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/linearLayout"
        android:layout_marginTop="15dp"/>


</androidx.constraintlayout.widget.ConstraintLayout>