如何動態地將線性布局（作為子項）添加到約束布局（父級）？

Question

我定義了一種方法來創建線性布局並將其添加到父布局。 但它沒有用。 我想我犯了錯​​誤。

    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

要向ConstraintLayout添加視圖，必須使用ConstraintSet添加約束。

在為約束布局添加動態視圖時，它與其他布局略有不同。 您需要指定約束，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);