How to programmatically add views and constraints to a ConstraintLayout?

Question

I'm having a problem to programmatically add views to a ConstraintLayout, and set up all the constraints required for the layout to work.

What I have at the moment doesn't work:

ConstraintLayout layout = (ConstraintLayout) findViewById(R.id.mainConstraint);
ConstraintSet set = new ConstraintSet();
set.clone(layout);

ImageView view = new ImageView(this);
layout.addView(view,0);
set.connect(view.getId(), ConstraintSet.TOP, layout.getId(), ConstraintSet.TOP, 60);
set.applyTo(layout);

The ImageView doesn't even appear on the layout. When adding to a RelativeLayout, it works like a charm.

What can I do to create the constraints I need, so that my layout work again?

Answer 1

I think you should clone the layout after adding your ImageView.

ConstraintLayout layout = (ConstraintLayout)findViewById(R.id.mainConstraint);
ConstraintSet set = new ConstraintSet();

ImageView view = new ImageView(this);
view.setId(View.generateViewId());  // cannot set id after add
layout.addView(view,0);
set.clone(layout);
set.connect(view.getId(), ConstraintSet.TOP, layout.getId(), ConstraintSet.TOP, 60);
set.applyTo(layout); // apply to layout