ConstraintLayout: modifie les contraintes par programme

Question

J'ai besoin d'aide avec ConstraintSet. Mon but est de modifier la vue de contraintes dans le code, mais je ne peux pas comprendre comment faire de ce droit.

J'ai 4 TextViews et un ImageView. J'ai besoin de configurer ImageView contraintes à l'un de la TextViews.

check_answer4 = (TextView) findViewById(R.id.check_answer4);
check_answer1 = (TextView) findViewById(R.id.check_answer1);
check_answer2 = (TextView) findViewById(R.id.check_answer2);
check_answer3 = (TextView) findViewById(R.id.check_answer3);

correct_answer_icon = (ImageView) findViewById(R.id.correct_answer_icon);

Si la 1ère réponse est juste, j'ai besoin de définir des contraintes d' ImageView de

app:layout_constraintRight_toRightOf="@+id/check_answer1"
app:layout_constraintTop_toTopOf="@+id/check_answer1"

Si la 2e réponse est juste, j'ai besoin de définir des contraintes d' ImageView de

app:layout_constraintRight_toRightOf="@+id/check_answer2"
app:layout_constraintTop_toTopOf="@+id/check_answer2"

Et ainsi de suite.

Answer 1

1. Pour définir les contraintes de la vue d'image sur:

    app:layout_constraintRight_toRightOf="@+id/check_answer1"
   app:layout_constraintTop_toTopOf="@+id/check_answer1"
    

   utilisation:

    ConstraintSet constraintSet = new ConstraintSet();
   constraintSet.clone(constraintLayout);
   constraintSet.connect(R.id.imageView,ConstraintSet.RIGHT,R.id.check_answer1,ConstraintSet.RIGHT,0);
   constraintSet.connect(R.id.imageView,ConstraintSet.TOP,R.id.check_answer1,ConstraintSet.TOP,0);
   constraintSet.applyTo(constraintLayout);
    

2. Pour définir les contraintes de la vue d'image sur:

    app:layout_constraintRight_toRightOf="@+id/check_answer2"
   app:layout_constraintTop_toTopOf="@+id/check_answer2"
    

   utilisation:

    ConstraintSet constraintSet = new ConstraintSet();
   constraintSet.clone(constraintLayout); 
   constraintSet.connect(R.id.imageView,ConstraintSet.RIGHT,R.id.check_answer2,ConstraintSet.RIGHT,0);      
   constraintSet.connect(R.id.imageView,ConstraintSet.TOP,R.id.check_answer2,ConstraintSet.TOP,0);
   constraintSet.applyTo(constraintLayout);
    

Answer 2

Supposons que nous souhaitons modifier les contraintes pendant l'exécution, en faisant en sorte que button1 soit aligné avec button2 lorsque l'utilisateur clique dessus:

Ensuite, ayant cette disposition:

 <android.support.constraint.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"
    android:id="@+id/root"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin">


    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button 1"
        app:layout_constraintTop_toTopOf="@+id/button3"
        app:layout_constraintBottom_toBottomOf="@+id/button3"
        app:layout_constraintStart_toEndOf="@+id/button3"
        android:layout_marginStart="0dp"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginEnd="0dp" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:text="Button 2"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        android:layout_marginStart="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginEnd="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="8dp"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintVertical_bias="0.5" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:text="Button 3"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        android:layout_marginStart="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginEnd="8dp"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="8dp"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintVertical_bias="0.223" />
</android.support.constraint.ConstraintLayout>
 

Nous pouvons faire ce qui suit:

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        button1.setOnClickListener {
            val params = button1.layoutParams as ConstraintLayout.LayoutParams
            params.leftToRight = button2.id
            params.topToTop = button2.id
            params.bottomToBottom = button2.id
            button1.requestLayout()
        }
    }