更改CursorAdapter的游标会产生staleDataException [英] changing cursor of CursorAdapter gives staleDataException
问题描述
我有2个listViews。一个是LV类,另一个是LV项。功能非常简单 - 当用户点击类别LV中的类别单元格时,与该类别匹配的所有项目都应过滤并显示在项目LV中。我这样做是通过为数据库中的每个项目分配'category integer'。因此,当点击一个类别时,会获取其整数id,并且在光标中加载项目数据库中与其匹配的所有ID。
问题:我使用adapter.changeCursor(newCursor)方法更改适配器中的基础数据。根据文档,此方法替换并关闭先前加载的游标。我收到此错误
11-08 11:54:15.939:E / AndroidRuntime(2056):android.database.StaleDataException:试图访问已关闭的CursorWindow。最可能的原因:在调用此方法之前光标已停用。
下面是代码解释:
itemAdapter = new CategoryCursorAdapter( this ,itemCursor,CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER, item_name, 1 ,date,db);
categoryLV.setOnItemClickListener( new AdapterView.OnItemClickListener(){
@ Override
public void onItemClick(AdapterView<?> arg0,View arg1,< span class =code-keyword> int arg2,
long arg3){
// TODO自动生成的方法存根
字符串 s =( (TextView)arg1.findViewById(R.id.category_name))。getText()。toString();
if (s.equalsIgnoreCase ( all)){
itemAdapter.changeCursor(null);
itemAdapter.notifyDataSetChanged();
}
else {
itemAdapter.changeCursor(db.getItemCursor(s));
itemAdapter.notifyDataSetChanged();
}
}
});
我在CursorAdapter类中收到错误:
public void bindView(查看视图,上下文上下文,光标游标){
/ / TODO自动生成的方法存根
如果(mcolumn == CATEGORY_LV) {
TextView tv =(TextView)view.findViewById(R.id.category_name);
tv.setText(mCursor.getString(mCursor.getColumnIndex(mColumnName)));
tv.setTextSize( 20 );
}
if (mcolumn == ITEM_LV){
TextView item =(TextView)view.findViewById(R .id.item_name);
TextView stock =(TextView)view.findViewById(R.id.stock_status);
// 我在这个地方得到了staleDataException
< span class =code-sdkkeyword> String s = mCursor.getString(mCursor.getColumnIndex(mColumnName));
按钮拖动=(按钮)view.findViewById(R.id.drag_button);
LinearLayout lv =(LinearLayout)view.findViewById(R.id.layout);
drag.setFocusable(false);
item.setText(s);
item.setTextSize( 20 );
stock.setText( 股票: + mdb.getStockStatus(mdb.getItemCode(s) ),mDate));
stock.setTextSize( 15 );
}
}
这里需要注意的一点是我使用相同的Adapter类来为两者提供电源listViews。但是我不认为这可能是个问题。
什么是mCursor?你是怎么创造它的?为什么不使用参数cursor来自
public < span class =code-keyword> void bindView(视图视图,上下文上下文,光标游标)
?
okay, so after going through tons of sites and blogs I have finally decided to ask this 'not so FAQ'.
I have 2 listViews. One as the 'category LV' and other as the 'item LV'. The functionality is quite simple- When the user clicks a category cell in the 'category LV', all the items matching that category should filter and appear in the 'item LV'. I do this by assigning the 'category integer' to every item in the database. So, when a category is tapped its integer id is taken and all the ids matching with it in the item database are loaded in the cursor.
PROBLEM: I use the adapter.changeCursor(newCursor) method to change the underlying data in the adapter. According to the docs, this method replaces and closes the previously loaded cursor. I am getting this error
11-08 11:54:15.939: E/AndroidRuntime(2056): android.database.StaleDataException: Attempting to access a closed CursorWindow.Most probable cause: cursor is deactivated prior to calling this method.
Down below is the code explained:
itemAdapter=new CategoryCursorAdapter(this, itemCursor, CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER, "item_name",1,date,db);
categoryLV.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
String s=((TextView)arg1.findViewById(R.id.category_name)).getText().toString();
if(s.equalsIgnoreCase("all")){
itemAdapter.changeCursor(null);
itemAdapter.notifyDataSetChanged();
}
else{
itemAdapter.changeCursor(db.getItemCursor(s));
itemAdapter.notifyDataSetChanged();
}
}
});
I get the error in the CursorAdapter class:
public void bindView(View view, Context context, Cursor cursor) {
// TODO Auto-generated method stub
if(mcolumn==CATEGORY_LV){
TextView tv=(TextView)view.findViewById(R.id.category_name);
tv.setText(mCursor.getString(mCursor.getColumnIndex(mColumnName)));
tv.setTextSize(20);
}
if(mcolumn==ITEM_LV){
TextView item=(TextView)view.findViewById(R.id.item_name);
TextView stock=(TextView)view.findViewById(R.id.stock_status);
// I get the staleDataException at this place
String s=mCursor.getString(mCursor.getColumnIndex(mColumnName));
Button drag=(Button)view.findViewById(R.id.drag_button);
LinearLayout lv=(LinearLayout)view.findViewById(R.id.layout);
drag.setFocusable(false);
item.setText(s);
item.setTextSize(20);
stock.setText("Stock:"+mdb.getStockStatus(mdb.getItemCode(s), mDate));
stock.setTextSize(15);
}
}
One thing to note here is that I am using the same Adapter class to power both the listViews. However i dont think this can be a problem.
what is mCursor? How did you create it? why don't you use the parametercursorthat from
public void bindView(View view, Context context, Cursor cursor)?
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