所以我尝试将我的一些回收器 ViewHolders 重构为 ConstraintLayouts。在我这样做之后，我看到的东西让我感到震惊。展开单个 View 比通常的 LinearLayout 多花费 20 倍的时间。它实际上在执行时跳过了很多帧。
编辑:约束布局的版本不相关。尝试不同的组合得到几乎相同的结果。
谁能解释一下为什么会这样？ 也许它不是为这种“沉重”的观点而设计的？
这是在 ViewHolder 中使用的根 XML:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/white"
android:elevation="@dimen/param_2"
android:orientation="vertical"
android:stateListAnimator="@animator/material_selector">
<LinearLayout
android:id="@+id/order_view_tabs_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="@dimen/param_2"
android:padding="@dimen/param_4"
android:background="@color/white"
android:divider="@drawable/empty_horizontal_divider"
android:elevation="@dimen/param_2"
android:orientation="horizontal"
android:showDividers="middle"
android:visibility="gone"/>
<include layout="@layout/order_list_item_constraint"/>
</LinearLayout>
这里是 order_list_item_constraint.xml
<android.support.constraint.ConstraintLayout
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="wrap_content"
android:padding="@dimen/param_4"
android:clipToPadding="false">
<TextView
android:id="@+id/delivery_status"
style="@style/DefaultText.Normal"
android:layout_width="0dp"
android:layout_height="50dp"
android:layout_marginEnd="4dp"
android:padding="4dp"
android:background="@color/white"
android:elevation="2dp"
android:gravity="center_vertical"
android:text="@string/main_swipe_list_item_info_title_delivered_time"
app:layout_constraintEnd_toStartOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:layout_editor_absoluteY="4dp"/>
<TextView
android:id="@+id/order_list_item_order_title"
style="@style/FullListItemInfoText"
android:layout_width="0dp"
android:layout_marginTop="4dp"
android:text="@string/main_swipe_list_item_info_title_order"
android:textColor="@color/red_900"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/delivery_status"/>
<TextView
android:id="@+id/order_list_item_order_id"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@+id/start_guideline"
app:layout_constraintTop_toBottomOf="@id/order_list_item_order_title"
/>
<TextView
android:id="@+id/order_list_item_price_title"
style="@style/FullListItemInfoText"
android:layout_width="0dp"
android:layout_marginTop="4dp"
android:text="@string/main_swipe_list_item_info_title_sum"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/order_list_item_order_id"
/>
<TextView
android:id="@+id/order_list_item_price"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@+id/start_guideline"
app:layout_constraintTop_toBottomOf="@id/order_list_item_price_title"
/>
<TextView
android:id="@+id/order_list_item_threshold_title"
style="@style/FullListItemInfoText"
android:layout_width="0dp"
android:layout_marginTop="4dp"
android:text="@string/order_full_list_item_threshold_value_title"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/order_list_item_price"
/>
<TextView
android:id="@+id/order_list_item_threshold_value"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@+id/start_guideline"
app:layout_constraintTop_toBottomOf="@id/order_list_item_threshold_title"
/>
<TextView
android:id="@+id/order_list_item_sl_title"
style="@style/FullListItemInfoText"
android:layout_width="0dp"
android:layout_marginTop="@dimen/param_4"
android:text="@string/main_swipe_list_item_info_title_service_level"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/order_list_item_threshold_value"/>
<TextView
android:id="@+id/order_list_item_service_level_title"
style="@style/FullListItemInfoDetailsText"
android:textStyle="bold"
android:layout_width="0dp"
android:textSize="@dimen/text_size_12"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/order_list_item_sl_title"/>
<TextView
android:id="@+id/order_list_item_service_level_try_on"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
android:textSize="@dimen/text_size_12"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/order_list_item_service_level_title"/>
<TextView
android:id="@+id/order_list_item_service_level_partial_purchase"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
android:textSize="@dimen/text_size_12"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/order_list_item_service_level_try_on"/>
<com.express.mobile.customView.MyNetworkImageView
android:id="@+id/order_list_item_image_map"
android:layout_width="0dp"
android:layout_height="144dp"
android:elevation="2dp"
android:scaleType="centerCrop"
android:visibility="visible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="@id/mid_guideline"
app:layout_constraintTop_toTopOf="parent"/>
<ImageView
android:id="@+id/order_list_item_map_pin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingBottom="@dimen/param_30"
android:contentDescription="@null"
android:elevation="2dp"
android:src="@drawable/ic_map_pin_sz_1"
android:visibility="gone"
app:layout_constrainedHeight="true"
app:layout_constrainedWidth="true"
app:layout_constraintBottom_toBottomOf="@id/order_list_item_image_map"
app:layout_constraintEnd_toEndOf="@id/order_list_item_image_map"
app:layout_constraintStart_toStartOf="@id/order_list_item_image_map"
app:layout_constraintTop_toTopOf="@id/order_list_item_image_map"/>
<include
android:id="@+id/order_list_item_map_interval_box"
layout="@layout/map_interval_box"
android:layout_width="wrap_content"
android:layout_height="@dimen/param_48"
app:layout_constrainedWidth="true"
app:layout_constraintStart_toStartOf="@id/order_list_item_image_map"/>
<TextView
android:id="@+id/order_list_item_timer"
style="@style/WhiteText.Large"
android:textStyle="bold"
android:layout_width="0dp"
android:layout_height="0dp"
android:background="@drawable/order_full_list_item_delivery_status_box_borders"
android:elevation="2dp"
android:gravity="center"
android:text="@string/timer_zero_time_value_text"
android:textSize="@dimen/text_size_24"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="@id/order_list_item_map_interval_box"
app:layout_constraintEnd_toEndOf="@id/order_list_item_map_interval_box"
app:layout_constraintStart_toStartOf="@id/order_list_item_map_interval_box"
app:layout_constraintTop_toTopOf="@id/order_list_item_map_interval_box"/>
<ImageView
android:id="@+id/order_list_item_partner_icon"
android:layout_width="@dimen/param_40"
android:layout_height="@dimen/param_40"
android:layout_margin="4dp"
android:background="@drawable/order_mod_icon"
android:backgroundTint="@color/red_800"
android:contentDescription="@null"
android:elevation="@dimen/param_4"
android:scaleType="center"
android:src="@drawable/ic_partner"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="@+id/order_list_item_image_map"
app:layout_constraintStart_toStartOf="@+id/order_list_item_image_map"/>
<ImageView
android:id="@+id/order_list_item_prepaid_icon"
android:layout_width="@dimen/param_40"
android:layout_height="@dimen/param_40"
android:layout_margin="4dp"
android:background="@drawable/order_mod_icon"
android:backgroundTint="@color/green_800"
android:contentDescription="@null"
android:elevation="@dimen/param_4"
android:scaleType="center"
android:src="@drawable/ic_prepaid"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="@+id/order_list_item_image_map"
app:layout_constraintStart_toEndOf="@id/order_list_item_partner_icon"/>
<ImageView
android:id="@+id/order_list_item_microcredit_icon"
android:layout_width="@dimen/param_40"
android:layout_height="@dimen/param_40"
android:layout_margin="4dp"
android:background="@drawable/order_mod_icon"
android:backgroundTint="@color/blue_grey_700"
android:contentDescription="@null"
android:elevation="@dimen/param_4"
android:scaleType="center"
android:src="@drawable/ic_microcredit"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="@+id/order_list_item_image_map"
app:layout_constraintStart_toEndOf="@id/order_list_item_prepaid_icon"/>
<ImageView
android:id="@+id/order_list_item_ongoing_icon"
android:layout_width="@dimen/param_40"
android:layout_height="@dimen/param_40"
android:layout_margin="4dp"
android:background="@drawable/order_mod_icon"
android:backgroundTint="@color/colorPrimaryDark"
android:contentDescription="@null"
android:elevation="@dimen/param_4"
android:scaleType="center"
android:src="@drawable/ic_delivery_time_ongoing"
android:visibility="gone"
app:layout_constraintBottom_toBottomOf="@+id/order_list_item_image_map"
app:layout_constraintStart_toEndOf="@id/order_list_item_microcredit_icon"/>
<TextView
android:id="@+id/order_list_item_name"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
android:layout_height="@dimen/param_20"
android:layout_marginTop="8dp"
android:drawablePadding="@dimen/param_8"
android:drawableStart="@drawable/ic_man"
android:maxLines="1"
app:layout_constraintEnd_toStartOf="@id/order_list_item_call_icon"
app:layout_constraintStart_toStartOf="@id/mid_guideline"
app:layout_constraintTop_toBottomOf="@id/order_list_item_image_map"/>
<TextView
android:id="@+id/order_list_item_phone"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
android:layout_height="@dimen/param_20"
android:layout_marginStart="@dimen/param_28"
android:maxLines="1"
app:layout_constraintEnd_toStartOf="@id/order_list_item_call_icon"
app:layout_constraintStart_toStartOf="@id/mid_guideline"
app:layout_constraintTop_toBottomOf="@id/order_list_item_name"/>
<ImageView
android:id="@+id/address_icon"
android:layout_width="@dimen/param_20"
android:layout_height="@dimen/param_20"
android:layout_marginTop="4dp"
android:contentDescription="@null"
android:src="@drawable/ic_address"
app:layout_constraintStart_toStartOf="@id/mid_guideline"
app:layout_constraintTop_toBottomOf="@id/order_list_item_phone"/>
<TextView
android:id="@+id/order_list_item_address"
style="@style/FullListItemInfoDetailsText"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_marginTop="4dp"
android:layout_marginStart="8dp"
android:layout_marginEnd="4dp"
android:minLines="2"
app:layout_constraintEnd_toStartOf="@id/order_list_item_call_icon"
app:layout_constraintStart_toEndOf="@id/address_icon"
app:layout_constraintTop_toBottomOf="@id/order_list_item_phone"/>
<ImageView
android:id="@+id/order_list_item_call_icon"
android:layout_width="38dp"
android:layout_height="38dp"
android:padding="@dimen/param_8"
android:background="@drawable/order_mod_icon"
android:contentDescription="@null"
android:elevation="@dimen/param_4"
android:src="@drawable/ic_call"
android:visibility="visible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="@id/order_list_item_name"/>
<ImageView
android:id="@+id/order_list_item_navigate_icon"
android:layout_width="38dp"
android:layout_height="38dp"
android:padding="@dimen/param_8"
android:background="@drawable/order_mod_icon"
android:contentDescription="@null"
android:elevation="@dimen/param_4"
android:src="@drawable/ic_order_navigate"
android:visibility="visible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="@id/order_list_item_address"/>
<android.support.constraint.Guideline
android:id="@+id/mid_guideline"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_end="360dp"/>
<android.support.constraint.Guideline
android:id="@+id/start_guideline"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_begin="4dp"
app:layout_constraintStart_toStartOf="parent"/>
</android.support.constraint.ConstraintLayout>
这是问题的证明。所有 subview 的测量时间都在 0.1 毫秒左右
比较简单的 LinearLayout
EDIT2:这是带有 LinearLayout 的布局版本: https://pastebin.com/ZvffUHnw
最佳答案
这绝对不是预期的 - 我将不得不进行更多调查以了解是什么原因造成的。请注意，1.1 beta 现在将比 1.0 慢，所有优化器传递都未启用。乍一看，有很多宽度为 0dp 的 textview，这是相当昂贵的——就像线性布局一样，0dp 将导致双重测量。例如。而不是:
<TextView
android:id="@+id/order_list_item_order_title"
android:layout_width="0dp"
android:layout_height="20dp"
android:layout_marginTop="4dp"
android:text="@string/main_swipe_list_item_info_title_order"
app:layout_constraintEnd_toEndOf="@id/mid_guideline"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/delivery_status"/>
你可以这样做:
<TextView
android:id="@+id/order_list_item_order_title"
android:layout_width="wrap_content"
android:layout_height="20dp"
android:layout_marginTop="4dp"
android:text="@string/main_swipe_list_item_info_title_order"
app:layout_constraintStart_toStartOf="@id/start_guideline"
app:layout_constraintTop_toBottomOf="@+id/delivery_status"/>
您也不需要在此处同时具有开始和结束约束，因为您正在使用指南。
请注意，一般来说，HierarchyViewer 不会为您提供准确的测量值(也就是说，有这么大的差异，那里似乎有问题)。
您的 com.express.mobile.customView.MyNetworkImageView 自定义 View 如何处理度量？当您将它设置为 0dp 时，它也会在您的布局中进行双重测量。
最后，您能否添加包含的布局 order_list_item_map_interval_box 中的内容？
编辑 1.1 beta 6 应该大大提高性能
关于android - ConstraintLayout onMeasure 非常慢，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48704493/