public class DataBindingAdapters {
    // 根据View的高度和宽高比，设置高度
    @BindingAdapter("widthHeightRatio")
    public static void setWidthHeightRatio(final View view, final double ratio) {
        view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                int width = view.getWidth();
                if (width > 0) {
                    view.getLayoutParams().height = (int) (width * ratio);
                    view.invalidate();
                    view.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                }
            }
        });
    }
}

使用

 <ImageView
            android:id="@+id/jdImg"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:scaleType="fitCenter"
            android:layout_marginTop="@dimen/dp_10"
            android:layout_marginLeft="15dp"
            android:layout_marginRight="15dp"
            android:layout_below="@+id/timeDate"
            app:widthHeightRatio="@{0.5}"
            android:onClick="@{()->viewModel.gojD()}"
            app:url="@{viewModel.imgUrl}">
        </ImageView>