如何使用数据绑定设置layout_gravity

Question

我正在尝试使用数据绑定将layout_gravity设置为LinearLayout。
这是我的布局：

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>

        <import type="android.view.Gravity" />

        <variable
            name="viewModel"
            type="com.example.viewModel.MessageViewModel" />
    </data>

    <LinearLayout
        android:id="@+id/messageAdapter_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="@{viewModel.isReceived ? Gravity.START : Gravity.END}"
            android:orientation="vertical"
            app:setBackground="@{viewModel.isReceived}">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@{viewModel.content}"
                android:textColor="@color/primaryTextColorInv" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="5dp"
                android:textAppearance="?android:textAppearanceSmall"
                android:textColor="@color/secondaryTextColorInv"
                android:textStyle="italic" />
        </LinearLayout>
    </LinearLayout>
</layout>

当viewModel.isReceived为true时，嵌套的LinearLayout应该与START对齐，当viewModel.isReceived为false时，应该与END对齐。但我遇到了这个错误：

Found data binding errors.
****/ data binding error ****msg:Cannot find the setter for attribute 'android:layout_gravity' with parameter type int on android.widget.LinearLayout.

不使用 @BindingAdapter，是否有可能实现这个功能？

- rand

---

https://stackoverflow.com/questions/40517660/how-can-i-use-android-databinding-to-dynamically-change-androidlayout-property - AskNilesh

https://dev59.com/uZHea4cB1Zd3GeqPutjN - AskNilesh

Answer 1

我发现将gravity属性设置到根LinearLayout上，而不是嵌套的LinearLayout上设置layout_gravity属性才是解决方案:

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>

        <import type="android.view.Gravity" />

        <variable
            name="viewModel"
            type="com.example.viewModel.MessageViewModel" />
    </data>

    <LinearLayout
        android:id="@+id/messageAdapter_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="@{viewModel.isReceived ? Gravity.START : Gravity.END}"
        android:orientation="horizontal">

        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:setBackground="@{viewModel.isReceived}"
            app:setMargin="@{viewModel.isReceived}">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@{viewModel.content}"
                android:textColor="@color/primaryTextColorInv" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="5dp"
                android:textAppearance="?android:textAppearanceSmall"
                android:textColor="@color/secondaryTextColorInv"
                android:textStyle="italic" />
        </LinearLayout>
    </LinearLayout>
</layout>

- rand