我正在寻找一种解决方案来加快更新我的微调器。目前,每当我根据先前选择的微调器更改搜索条件时,我正在使用 SimpleCursorAdapter 并调用 ChangeCursor。
我做了一些时间测试,查询需要 5ms 到 60ms,而 changeCursor 函数需要 600ms 到 4000ms+。是否有另一种方法可以更快地更新适配器上的光标?我没有使用相同的查询,所以我不能简单地重新查询游标,然后调用 notifydatasetchanged。我必须创建一个新查询然后取回一个新光标(也许有更好的方法来完成这部分)。
这是我目前的填充方式
private void writerSpinner() {
String[] columns = new String[] { Passage.COL_WRITER_ID + " " + BaseColumns._ID, Passage.COL_WRITER_NAME };
String whereClause = null;
String groupBy = null;
String orderBy = Passage.COL_WRITER_ID + " ASC";
if (mAdapterPassage == null) {
String[] columnsSpinner = new String[] { Passage.COL_WRITER_NAME };
int[] to = new int[] { android.R.id.text1 };
mAdapterPassage = new SimpleCursorAdapter(getActivity(), android.R.layout.simple_spinner_item, null, columnsSpinner, to);
mAdapterPassage.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mPassage.setAdapter(mAdapterPassage);
mPassage.setOnItemSelectedListener(onItemSelectedListener);
}
AsyncLoadData loadData = new AsyncLoadData(mAdapterPassage, mPassage, Passage.TABLE_NAME_WRITERS, columns, whereClause, groupBy, orderBy);
loadData.execute();
}
private void updateChapterSpinner() {
String[] columns = new String[] { Passage.COL_WRITER_ID + " " + BaseColumns._ID, Passage.COL_CHAPTER_ID };
String whereClause = Passage.COL_WRITER_ID + " = " + mSelectedWriterId;
String groupBy = Passage.COL_CHAPTER_ID;
String orderBy = Passage.COL_CHAPTER_ID + " ASC";
if (mAdapterChapter == null) {
String[] columnsSpinner = new String[] { Passage.COL_CHAPTER_ID };
int[] to = new int[] { android.R.id.text1 };
mAdapterChapter = new SimpleCursorAdapter(getActivity(), android.R.layout.simple_spinner_item, null, columnsSpinner, to);
mAdapterChapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mChapter.setAdapter(mAdapterChapter);
mChapter.setOnItemSelectedListener(onItemSelectedListener);
}
AsyncLoadData loadData = new AsyncLoadData(mAdapterChapter, mChapter, Passage.TABLE_NAME_PASSAGES, columns, whereClause, groupBy, orderBy);
loadData.execute();
}
private void updateVerseSpinner() {
String[] columns = new String[] { Passage.COL_WRITER_ID + " " + BaseColumns._ID, Passage.COL_VERSE_ID };
String whereClause = Passage.COL_WRITER_ID + " = " + mSelectedWriterId
+ " AND " + Passage.COL_CHAPTER_ID + " = " + mSelectedChapter;
String groupBy = Passage.COL_VERSE_ID;
String orderBy = Passage.COL_VERSE_ID + " ASC";
if (mAdapterVerse == null) {
String[] columnsSpinner = new String[] { Passage.COL_VERSE_ID };
int[] to = new int[] { android.R.id.text1 };
mAdapterVerse = new SimpleCursorAdapter(getActivity(), android.R.layout.simple_spinner_item, null, columnsSpinner, to);
mAdapterVerse.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mVerse.setAdapter(mAdapterVerse);
mVerse.setOnItemSelectedListener(onItemSelectedListener);
}
AsyncLoadData loadData = new AsyncLoadData(mAdapterVerse, mVerse, Passage.TABLE_NAME_PASSAGES, columns, whereClause, groupBy, orderBy);
loadData.execute();
}
private class AsyncLoadData extends AsyncTask<Void, Void, Void> {
String mTableName;
String[] mColumns;
String mWhereClause;
String mGroupBy;
String mOrderBy;
Spinner mSpinner;
Cursor mCursor;
SimpleCursorAdapter mAdapter;
public AsyncLoadData(SimpleCursorAdapter adapter, Spinner spinner, String tableName, String[] columns, String whereClause, String groupBy, String orderBy) {
mAdapter = adapter;
mSpinner = spinner;
mTableName = tableName;
mColumns = columns;
mWhereClause = whereClause;
mGroupBy = groupBy;
mOrderBy = orderBy;
}
@Override
protected void onPreExecute()
{
//mSpinner.setVisibility(View.GONE);
}
@Override
protected Void doInBackground(Void... arg0) {
long startCursor = new Date().getTime();
mCursor = mDBHandler.query(mTableName, mColumns, mWhereClause, null, mGroupBy, null, mOrderBy);
long timeToQuery = new Date().getTime() - startCursor;
Log.i("CursorQuery", "Time to Query Cursor " + mGroupBy + ": " + timeToQuery + "ms");
return null;
}
@Override
protected void onPostExecute(Void result)
{
long startAdapter = new Date().getTime();
mAdapter.changeCursor(mCursor);
long timeToChangeCursor = new Date().getTime() - startAdapter;
Log.i("AdapterQuery", "Time to Change Cursor " + mGroupBy + ": " + timeToChangeCursor + "ms");
mAdapter.notifyDataSetChanged();
//mSpinner.setVisibility(View.VISIBLE);
}
}
private OnItemSelectedListener onItemSelectedListener = new OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
switch(parent.getId()) {
case R.id.bible_passage:
mSelectedWriterId = position + 1;
updateChapterSpinner();
break;
case R.id.bible_chapter:
mSelectedChapter = position + 1;
updateVerseSpinner();
break;
case R.id.bible_verse:
mSelectedVerse = position + 1;
break;
}
}
public void onNothingSelected(AdapterView<?> parent) {
}
};