与ListView和CursorAdapter的对于大数据量的性能问题 [英] Performance issue with ListView and CursorAdapter for large amount of data

问题描述

我在SQLite表约4K行，表中有7列。

I have about 4k rows in sqlite table, table has 7 columns.

我创建工作的ListView用我自己的CursorAdapter。

I created working ListView with my own CursorAdapter.

查询是这样的 SELECT * FROM [表] ORDER BY [专栏] DESC;

表具有第一列 _id INTEGER PRIMARY KEY ，但顺序由另一列完成。

Table has first column _id INTEGER PRIMARY KEY but ordering is done by another column.

有关使用我自己的 SQLiteOpenHelper

创建光标

mySQLiteOpenHelper pm = new mySQLiteOpenHelper();
SQLiteDatabase db = pm.getReadableDatabase();
Cursor c = db.query([tablename], new String[]{"_id", "[column]", "[column]", "[column]", "[column]", "[column]"}, null, null, null, null, "name ASC");

将它传递给的ListView

Passing it to ListView

ListView lv = (ListView) findViewById(R.id.list_items);
lv.setOnItemClickListener(this);
pa = new ItemsAdapter(ItemsActivity.this, c);

在ItemsAdapter我已经重新实现

In ItemsAdapter I have reimplemented

private LayoutInflater inflater;

@Override
public View newView(Context arg0, Cursor arg1, ViewGroup arg2) {
    return inflater.inflate(R.layout.items_row, arg2,false);
}

和

@Override
public void bindView(View rtn, Context arg1, Cursor c) {
    item_name = (TextView) rtn.findViewById(R.id.item_name);
    item_description = (TextView) rtn.findViewById(R.id.item_description);
    item_catalog_id = (TextView) rtn.findViewById(R.id.item_catalog_id);
    item_true_price = (TextView) rtn.findViewById(R.id.item_true_price);
    item_display_price = (TextView) rtn.findViewById(R.id.item_display_price);
    item_button = (Button) rtn.findViewById(R.id.item_button);

    item = new MyWrapClass(c);

    // some work with item to fill up all UI items

}

MyWrapClass

MyWrapClass

public final class MyWrapClass {

    public String name = "";
    public String notes = "";
    public int id = 0;
    public String catalogId = "";
    public int price = 0;
    public int publicPrice = 0;
    public String groupPrice = "";
    public int order_count = 0;

    public MyWrapClass(Cursor c) {
        try {
            id = c.getInt(0);
            catalogId = c.getString(1);
            name = c.getString(2);
            price = c.getInt(3);
            publicPrice = c.getInt(4);
            groupPrice = c.getString(5);
        } catch (Exception e) {
            e.printStackTrace(System.err);
        }
    }
}

在同一行的init code的ListView中使用，并且它的工作非常好。

The same row init code was used in ListView and there it worked very good.

所以，如果你可以从这个code说，没有任何理由，为什么要加载第6行项目（一个屏幕高度），并滚动刷新（当您滚动一个项目下来的意思）需要1分钟的时间？

So if you can say from this code, is there ANY reason, why should load of 6 row items (one screen height) and scroll refresh (mean when you scroll one item down) take up to 1 minute?

的ListView只加载最多需要2分钟，然后大约有一半的时间来滚动一个列表项下/上。在哪里可以是性能问题？

Just load of ListView takes up to 2 minutes, and then about half time to scroll one list item down/up. Where can be the performance issue?

推荐答案

我想创建一个自定义的适配器，只无论是需要积极的意见和负载重用在 getView（）法的意见。这真的很简单。

I'd create a custom Adapter, that only loads whatever is needed for the active views and that reuses views in the getView() method. It's really quite simple.

更新

我发现了一个很好的例子，你应该能够使用：
http://android.amberfog.com/?p=296

I found an excellent example, that you should be able to use: http://android.amberfog.com/?p=296

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