以编程方式设置 ConstraintLayout 宽度以匹配父宽度

Question

在 android 应用程序中，我试图以编程方式将自定义ConstraintLayout视图添加到垂直方向的LinearLayout 。

我在ConstraintLayout中将LayoutParams设置为MATCH_PARENT的宽度和WRAP_CONTENT的高度。 但是，当我运行应用程序时， ConstraintView全部被压缩并且内容重叠。 下面是一些相关的片段和我的应用程序的屏幕截图。 我该如何解决这个问题？

public class ItemView extends ConstraintLayout {
    LinearLayout linearButtons;
    LinearLayout linearText;
public ItemView(Context context, String name, String price, ArrayList<String> guests, 
   ArrayList<String> checked, int id) {
...
    addView(linearText);
    addView(linearButtons);
    set.clone(this);
    set.connect(linearText.getId(), ConstraintSet.LEFT, this.getId(), 
      ConstraintSet.LEFT, 8);
    set.connect(linearText.getId(), ConstraintSet.TOP, this.getId(), 
     ConstraintSet.TOP, 8);
    set.connect(linearButtons.getId(), ConstraintSet.RIGHT, this.getId(), 
     ConstraintSet.RIGHT, 8);
    set.connect(linearButtons.getId(), ConstraintSet.TOP, this.getId(), 
     ConstraintSet.TOP, 8);
}

别处：

for (Item it:r.getItems()) {
        ItemView itemView = new ItemView(this, it.getName(), nf.format(it.getPrice()), dinerlist, it.getGuests(), i);
        ConstraintLayout.LayoutParams params = new ConstraintLayout.LayoutParams(ConstraintLayout.LayoutParams.MATCH_PARENT, ConstraintLayout.LayoutParams.MATCH_PARENT);
        itemView.setLayoutParams(params);
        vg.addV[enter image description here][1]iew(itemView);
        Log.d("ItemView Children: ", itemView.getWidth()+" "+itemView.getHeight());

Answer 1

在 xml 中的 ConstraintLayout 中，当您想要“MATCH_PARENT”宽度时，必须将宽度设置为 0dp，然后将 layout_constraintWidth_default 属性设置为“spread”

以编程方式，您可以执行相同的操作：

a) 设置一个 0 dp 的宽度和高度

b) 设置 defaultWidth 和 defaultHeight 约束

    //add the view with 0dp width and height
    val layoutParams = ConstraintLayout.LayoutParams(0, 0)
    val view = View(context)
    view.layoutParams = layoutParams
    view.id = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) View.generateViewId() else R.id.yourLayoutId
    parent.addView(view)

    //apply the default width and height constraints in code
    val constraints = ConstraintSet()
    constraints.clone(parent)
    constraints.constrainDefaultHeight(view.id, ConstraintSet.MATCH_CONSTRAINT_SPREAD)
    constraints.constrainDefaultWidth(view.id, ConstraintSet.MATCH_CONSTRAINT_SPREAD)
    constraints.applyTo(parent)

如果您需要 Java：

    //add the view with 0dp width and height
    ConstraintLayout.LayoutParams layoutParams = new ConstraintLayout.LayoutParams(0, 0);
    View view = View(context);
    view.setLayoutParams(layoutParams);
    view.setId(R.id.yourLayoutId);
    parent.addView(view);

    //apply the default width and height constraints in code
    ConstraintSet constraints = new ConstraintSet();
    constraints.clone(parent);
    constraints.constrainDefaultHeight(view.getId(), ConstraintSet.MATCH_CONSTRAINT_SPREAD);
    constraints.constrainDefaultWidth(view.getId(), ConstraintSet.MATCH_CONSTRAINT_SPREAD);
    constraints.applyTo(parent);