小编Kęs*_*kas的帖子

所以我尝试重构我的一些回收的ViewHolders到ConstraintLayouts.我做完之后,在看到之后感到震惊.对单个视图进行充气所需的时间比平常多20倍LinearLayout.它实际上在执行时会跳过这么多帧.

编辑:约束布局的版本不相关.试过不同的组合有几乎相同的结果.

任何人都能解释为什么会这样吗？也许它不是为这种"沉重"的观点而设计的？

以下是XML用于以下内容的根ViewHolder:

<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"
        /> …

好吧,我开始了解Android碎片,但这对我来说仍然很困惑.我需要一些帮助.因为它说自API级别11以来支持android片段,但您可以下载"support.v4"库包以获得更低级别的API.首先,我创建新的项目来尝试API级别15的片段.然后我做了同样的API级别8,它不起作用...我导入外部jar,它看到所有需要导入,因为它应该...似乎这是问题吗？

这是我的主要课程:

import android.support.v4.app.FragmentActivity;
import android.os.Bundle;

public class Fragment2Activity extends FragmentActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

我的主要布局XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

        <fragment 
   android:name="com.frag.Fragment2.frag"
   android:id="@+id/frag"
   android:layout_width="match_parent"
   android:layout_height="match_parent" />

</LinearLayout>

我的片段类:

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class frag extends Fragment {
       @Override
       public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { …

我很困惑使用ListFragment ......我无法理解问题出在哪里......

这是我的FragmentActivity类:

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;

public class menu extends FragmentActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
            setContentView(R.layout.root_menu); 

        if (getSupportFragmentManager().findFragmentById(android.R.id.content) == null) {
            ListFrag list = new ListFrag();
            getSupportFragmentManager().beginTransaction().replace(android.R.id.content, list).commit();
        }}}

我的ListFragment类:

public class ListFrag extends ListFragment {

    int Files = 0;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub

        getListView().setBackgroundResource(R.drawable.table);
        getListView().setDividerHeight(0);
        getListView().setCacheColorHint(0);

        View view = inflater.inflate(R.layout.main, null);

        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        setListAdapter(new CustomListAdapter(getActivity(), …