Use of constraintlayout

1. Positioning position

The other side of the control and   Align the other side of the control

• layout_constraintLeft_toLeftOf  Align left and left
• layout_constraintLeft_toRightOf  Align left and right
• layout_constraintRight_toLeftOf  Align right and left
• layout_constraintRight_toRightOf
• layout_constraintTop_toTopOf
• layout_constraintTop_toBottomOf
• layout_constraintBottom_toTopOf
• layout_constraintBottom_toBottomOf
• layout_constraintBaseline_toBaselineOf
• layout_constraintStart_toEndOf
• layout_constraintStart_toStartOf
• layout_constraintEnd_toStartOf
• layout_constraintEnd_toEndOf
• 

 

2. Align center

Simultaneous setting ：

Horizontal center ：

app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"

Center vertically ：

app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"

The offset

• layout_constraintHorizontal_bias  Shift left and right     Value range   0~1
• layout_constraintVertical_bias      Up and down    Value range   0~1

3.margin Set up

Use at the same time  

android:layout_marginXXX="30dp"
app:layout_constraintXXX_toBottomOf="@+id/insert"