Question

我遇到了以编程方式向Constraint Layout添加视图的问题，并设置了布局工作所需的所有约束。

我现在拥有的东西不起作用：

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);

ImageView甚至没有出现在布局上。添加到RelativeLayout时，它就像魅力一样。

如何创建我需要的约束，以便我的布局再次工作？

Answer 1

我认为你应该在添加ImageView后克隆布局。

 DECLARE @str VARCHAR(MAX)

 SELECT @str = ISNULL(@str+',','') + QUOTENAME(aa.KodeVerifikasi,'''') 

 From TVerifikasiPOFakturHeader as aa (NOLOCK)        

 INNER JOIN TVerifikasiPOFakturDetail as bb (NOLOCK) on
                                aa.KodeVerifikasi=bb.KodeVerifikasi        

 WHERE aa.KodePO='TS/01/15/00183' 

 GROUP BY aa.KodeVerifikasi       

 ORDER BY aa.KodeVerifikasi        

 SELECT @str

Answer 2

将此 How do I add elements dynamically to a view created with XML 与 https://stackoverflow.com/a/40527407/4991437 合并

我发现了一个“更简单”的解决方案。这最适合添加使用 Viewbinding 和 ViewModel

的多个一致视图

创建fragment_home.xml
在fragment_home.xml底部添加一个LinearLayout
创建一个 dynamic_view.xml，您将对其进行扩充
从 ViewModel/Array 或任何可用数据源获取元素
膨胀并添加元素

在这种情况下，我正在创建一个带有 recyclerview 的文本视图（标题）[有用于此的库，但是，我发现这样做有更多控制权]

步骤 1,2

<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView 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"
    tools:context=".ui.hometab.HomeFragment">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/constraint_parent"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <!-- otherviews here -->

        <LinearLayout
            android:id="@+id/dynamic_linear_layout"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/margin_large"
            android:orientation="vertical"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/curated_recycler" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.core.widget.NestedScrollView>

第三步

    <?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/dynamic_constraint"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_begin="@dimen/margin_large"
        app:layout_constraintStart_toStartOf="parent" />

    <View
        android:id="@+id/title_view"
        android:layout_width="0dp"
        android:layout_height="40dp"
        android:layout_gravity="center"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <TextView
        android:id="@+id/shop_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/diary"
        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
        android:textColor="@android:color/black"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="@+id/title_view"
        app:layout_constraintStart_toStartOf="@id/guideline"
        app:layout_constraintTop_toTopOf="@+id/title_view" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/shop_recycler"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:clipToPadding="false"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="@id/guideline"
        app:layout_constraintTop_toBottomOf="@+id/title_view" />

</androidx.constraintlayout.widget.ConstraintLayout>

步骤 4,5

    binding = FragmentHomeBinding.inflate(getLayoutInflater());

    ShopViewModel shopViewModel = new ViewModelProvider(this).get(ShopViewModel.class);
    shopViewModel.getAllShops(false).observe(getViewLifecycleOwner(), shopEntities -> {
        List<ConstraintLayout> shopConstraints = new ArrayList<>();

        for (ShopEntity shopEntity : shopEntities) {
            // get an instance of the dynamic_view.xml
            DynamicViewBinding dynamicViewBinding = DynamicViewBinding.inflate(getLayoutInflater());
            // add text view content
            dynamicViewBinding.shopName.setText(shopEntity.getName());
            // initialize the recycler layout adapter
            dynamicViewBinding.shopRecycler.setLayoutManager(new ProductCardLayoutManager(getContext(), 1,
                    GridLayoutManager.HORIZONTAL, false, 80));

            // get all products and add them to recycler view
            productViewModel.getAllProductsByShop(shopEntity.getShopId(), 10).observe(getViewLifecycleOwner(), productEntities ->
                    dynamicViewBinding.shopRecycler.setAdapter(new ProductAdapter(getActivity(), productEntities)));

            // attach dynamic view to list of dynamic constraint layouts
            shopConstraints.add(dynamicViewBinding.getRoot());
        }

        // remove all previous views from the linear layout
        binding.dynamicLinearLayout.removeAllViews();

        // add the new views
        for (ConstraintLayout shopConstraint : shopConstraints) {
            binding.dynamicLinearLayout.addView(shopConstraint);
        }
    });

如何以编程方式将视图和约束添加到ConstraintLayout？

2 个答案: