滚动ListView时使用大量GC(带支架图案)

Question

这是一个类似的问题,这个,但解决方案不起作用.

问题是滚动ListView非常缓慢,这是因为有很多很多的GC.我使用holder pattern(视图缓存),如下面的代码所示:

public View getView(int position, View convertView, ViewGroup parent) {

    ViewHolder holder;

    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.eventrow, parent, false);

        holder = new ViewHolder();

        holder.title = (TextView) convertView.findViewById(R.id.eventTitle);
        holder.place = (TextView) convertView.findViewById(R.id.eventPlace);

        convertView.setTag(holder);
    } else {
        // Get the ViewHolder back to get fast access to the TextView
        // and the ImageView.
        holder = (ViewHolder) convertView.getTag();
    }

    // Bind the data efficiently with the holder.
    holder.title.setText(((EventItem) getItem(position)).getTitle());
    holder.place.setText(((EventItem) getItem(position)).getPlace_name());

    return convertView;
}

我cacheColorHint从列表视图和行中删除了自定义选择器:

<ListView
android:id="@+id/android:list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>

这是日志的样子:

08-20 19:36:24.286: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 364K, 46% free 3944K/7239K, external 1196K/1445K, paused 54ms
08-20 19:36:24.356: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 228K, 49% free 3716K/7239K, external 1721K/1970K, paused 52ms
08-20 19:36:24.456: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 5K, 49% free 3726K/7239K, external 2214K/2463K, paused 50ms
08-20 19:36:24.546: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 2K, 49% free 3726K/7239K, external 2214K/2463K, paused 43ms
08-20 19:36:24.636: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 2K, 49% free 3726K/7239K, external 2214K/2463K, paused 44ms
08-20 19:36:24.696: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 50ms
08-20 19:36:24.766: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 46ms
08-20 19:36:24.846: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 46ms
08-20 19:36:24.906: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 46ms
08-20 19:36:24.986: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 46ms
08-20 19:36:25.056: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 47ms
08-20 19:36:25.136: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 46ms
08-20 19:36:25.196: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 46ms
08-20 19:36:25.296: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 48ms
08-20 19:36:25.356: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3726K/7239K, external 2214K/2463K, paused 43ms
08-20 19:36:34.596: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 7K, 49% free 3740K/7239K, external 2214K/2463K, paused 51ms
08-20 19:36:34.656: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed 1K, 49% free 3739K/7239K, external 2214K/2463K, paused 50ms
08-20 19:36:34.746: D/dalvikvm(12036): GC_EXTERNAL_ALLOC freed <1K, 49% free 3739K/7239K, external 2214K/2463K, paused 50ms

编辑: 似乎问题(几乎)只在第ListFragment一次充气时出现.首先向下滚动,然后向上滚动.之后,GC并不常见.但有时每次滚动时都会出现GC.我在这里看不到规律性. PLUS我可以看到的HTC Desire(2.3.7 MIUI),但不是在Sasmung银河ACE(2.1)的问题.它只会让人感到困惑......

不太令人满意的解决方案: 当我使用时

android:scrollingCache="false"
android:animationCache="false"

在我的listview中似乎没问题.但是文档说如果我理解的话应该完全不同,所以我有点困惑.

我哪里弄错了？怎样做才能拥有流畅的滚动列表视图？或者禁用会scrollingCache产生一些我现在看不到的负面影响？

Answer 1

尝试

listView.setCacheColorHint(0);

         &
protected void onDestroy() {
        System.gc();

        super.onDestroy();
    }