大量的垃圾收集在一个列表视图 [英] Lots of garbage collection in a listview

问题描述

我有一个使用自定义适配器的ListView。自定义适配器的getView使用所有推荐做法：

I have a ListView that uses a custom adapter. The custom adapter's getView uses all the recommended practices:

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    SuscriptionsViewsHolder holder;
    ItemInRootList item = mItemsInList.get(position);

    if (convertView == null) {
         convertView = mInflater.inflate(R.layout.label, null);

         holder = new SuscriptionsViewsHolder();
         holder.label = (TextView) convertView.findViewById(R.id.label_label);
         holder.icon = (ImageView) convertView.findViewById(R.id.label_icon);

        convertView.setTag(holder);
    } else {
        holder = (SuscriptionsViewsHolder) convertView.getTag();
    }

    String text = String.format("%1$s (%2$s)", item.title, item.unreadCount);
    holder.label.setText(text);
    holder.icon.setImageResource(item.isLabel ? R.drawable.folder : R.drawable.file );

    return convertView;
}

然而，当我滚动，这是因为沉重的垃圾回收不畅：

However when I scroll, it is sluggish because of heavy garbage collection:

GC_EXTERNAL_ALLOC freed 87K, 48% free 2873K/5447K, external 516K/519K, paused 30ms
GC_EXTERNAL_ALLOC freed 7K, 48% free 2866K/5447K, external 1056K/1208K, paused 29ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2866K/5447K, external 1416K/1568K, paused 28ms
GC_EXTERNAL_ALLOC freed 5K, 48% free 2865K/5447K, external 1600K/1748K, paused 27ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2865K/5447K, external 1780K/1932K, paused 30ms
GC_EXTERNAL_ALLOC freed 2K, 48% free 2870K/5447K, external 1780K/1932K, paused 26ms
GC_EXTERNAL_ALLOC freed 2K, 48% free 2870K/5447K, external 1780K/1932K, paused 25ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 26ms
GC_EXTERNAL_ALLOC freed 3K, 48% free 2870K/5447K, external 1780K/1932K, paused 25ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 29ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 29ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2871K/5447K, external 1780K/1932K, paused 28ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2871K/5447K, external 1780K/1932K, paused 26ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 27ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 29ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 26ms
GC_EXTERNAL_ALLOC freed <1K, 48% free 2870K/5447K, external 1780K/1932K, paused 34ms

什么似乎是错的？

What seems to be wrong?

编辑@ 12：47格林尼治标准​​时间：

EDIT @12:47 GMT:

在实际上它是稍微比这更复杂。我的应用程序的用户界面是基于两部分。一个是屏幕的大脑，创造了意见，处理用户输入等。另一种是片段如果该设备具有的Andr​​oid 3.0，否则它是一个活动。

In fact it's slightly more complicated than this. My app UI is based on 2 parts. One is the brain of a screen, creating the views, handling user input, etc. The other is a Fragment if the device has android 3.0, otherwise it's an Activity.

GC的发生在我的Nexus One 2.3.3设备，因此，使用活动。我没有我的Xoom和我一起测试用的行为片段。

The GC happened on my Nexus One 2.3.3 device, so using the Activity. I don't have my Xoom with me to test the behaviour with a Fragment.

如果需要，我可以公布源，但让我试着解释一下：

I could post the source if required, but let me try to explain it :

• RootList 是UI的大脑。它包含 ：
  • 在名单，其中;＆GT; 将被放置在的ListView 项目
  • 是建立此列表从一个SQLite数据库的方法
  • 包含基本上只有getView方法上面粘贴一个自定义的BaseAdapter
  • RootList is the brain of the UI. It contains :
    • a List<> of items that will be placed in the ListView.
    • a method that builds this list from a SQLite db
    • a custom BaseAdapter that contains basically only the getView method pasted above
    • 在使用XML布局
    • 布局当然有id为一个ListView android.id.list
    在创建活动时，
    • 的活动回调被转发到使用RootList实例的 RootList 类创建（构造函数，而不是的onCreate ）
    • 在的onCreate ，我称之为 RootList 的方法，将创建的项目列表中，并设置列表数据到我的自定义类从 BaseAdapter 派生的新实例
    • uses an XML layout
    • the layout has of course a listview with id android.id.list
    • the Activity callbacks are forwarded to the RootList class using an instance of RootList created when the activity is created (constructor, not onCreate)
    • in the onCreate, I call RootList's methods that will create the list of items, and set the list data to a new instance of my custom class derived from BaseAdapter

    编辑于5月17日@下午9时36分格林尼治标准​​时间：

    EDIT on may 17th @ 9:36PM GMT:

    下面是活动的code和做的事情类。 http://pastebin.com/EgHKRr4r

    Here's the code of the Activity and the class that does the things. http://pastebin.com/EgHKRr4r

    推荐答案

    我发现这个问题。该活动我的XML布局是：

    I found the issue. My XML layout for the activity was:

    <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
    
        <include android:id="@+id/rootlist_header" layout="@layout/pre_honeycomb_action_bar" />
    
        <ListView android:id="@android:id/list"
            android:layout_below="@id/rootlist_header"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_weight="1"
            android:textColor="#444444"
            android:divider="@drawable/list_divider"
            android:dividerHeight="1px"
            android:cacheColorHint="#00000000" />
    
    </RelativeLayout>
    

    如果我删除安卓cacheColorHint =＃00000000，重GC出来了，而滚动的的顺利的！ ：）

    If I remove the android:cacheColorHint="#00000000", the heavy GC is out, and the scrolling is smooth! :)

    我真的不知道为什么这个参数设置，因为我并不需要它。也许我copypasted太多，而不是真正建立我的XML布局。

    I don't really know why this parameter was set, because I don't need it. Maybe I copypasted too much instead of actually build my XML layout.

    感谢您的支持，我真的很美联社preciate你的帮助。

    THANK YOU for your support, I really appreciate your help.

    这篇关于大量的垃圾收集在一个列表视图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！