java如何将线性布局（作为子布局）动态添加到约束布局（父布局）？

Question

我定义了一个方法来创建线性布局并将其添加到父布局。但它不起作用。我想我犯了个错误

    public void methodName() {
        LinearLayout linearLayout = new LinearLayout(MainActivity.this);
        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
        linearLayout.setLayoutParams(params);
        linearLayout.setOrientation(LinearLayout.HORIZONTAL);
        linearLayout.setBackgroundColor(Color.RED);
        ConstraintLayout main = (ConstraintLayout) findViewById(R.id.mainLayout);
        main.addView(linearLayout);
   }

Answer 1

要将视图添加到ConstraintLayout，必须使用ConstraintSet添加约束

将动态视图添加到约束布局时，它与其他布局略有不同。您需要指定约束条件，如下所示：-

     ConstraintLayout main = (ConstraintLayout) findViewById(R.id.mainLayout);
     ConstraintSet set = new ConstraintSet();

     LinearLayout linearLayout = new LinearLayout(MainActivity.this);
     LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
     linearLayout.setLayoutParams(params);
     linearLayout.setOrientation(LinearLayout.HORIZONTAL);
     linearLayout.setBackgroundColor(Color.RED);
     main.addView(linearLayout,0);
     set.clone(main);
     set.connect(linearLayout.getId(), ConstraintSet.TOP, main.getId(), ConstraintSet.TOP, 60);
     set.applyTo(main);