以编程方式获取约束的ID

问题描述：

给出以下xml：

<ImageView
    android:id="@+id/someTag"
    android:layout_width="10dp"
    android:layout_height="10dp"
    android:layout_marginBottom="12dp"
    android:layout_marginStart="8dp"
    android:tag="someTag"
    app:layout_constraintBottom_toTopOf="@+id/someID"
    app:layout_constraintStart_toEndOf="@+id/someID"

我想知道如何获取

app:layout_constraintBottom_toTopOf

（即 someID

非常感谢！

答

该属性值被保存在 ImageView 的 LayoutParams 中，具体来说是 ConstraintLayout.LayoutParams ，在在这种情况下，因为它的父级是 ConstraintLayout 。

That attribute value is held in the ImageView's LayoutParams, which are specifically ConstraintLayout.LayoutParams, in this case, since its parent is the ConstraintLayout.

ConstraintLayout.LayoutParams 具有 bottomToTop 字段，其中包含该特定约束的视图的ID。

只需获取 ImageView 的 LayoutParams ，并将其转换为 ConstraintLayout.LayoutParams ，然后从上述字段中获取您的ID。例如：

Simply get the ImageView's LayoutParams, cast them to ConstraintLayout.LayoutParams, and get your ID from the aforementioned field. For example:

ImageView image = findViewById(R.id.someTag);
ConstraintLayout.LayoutParams lp = (ConstraintLayout.LayoutParams) image.getLayoutParams();
int bottomToTopId = lp.bottomToTop;

如果出于某种原因，您需要实际ID的资源名称，您可以使用 Resources＃getResourceEntryName（）方法照常获取它。即：

If, for some reason, you need the actual resource name for that ID, you can get it per usual with the Resources#getResourceEntryName() method. That is:

String viewIdName = getResources().getResourceEntryName(bottomToTopId); // returns "someID"

以编程方式获取约束的ID

相关推荐