我正在尝试使用SimpleCursorAdapter在ListView中实现Alphabet-Index。 它正在工作，但它非常慢，当我试图上下滚动列表时，手机正在被击中。我认为它正在发生，因为我的编码方式由于缺乏知识。所以我需要知道这个代码的错误或错误是什么。如果除此之外还有其他方式，请告诉我。
这是具有上述问题的片段代码集。
{
"name": "doors_right",
"rotation_point": {
"px": 49,
"py": 0,
"pz": 26,
"onclick": [{
"rx": 0,
"ry": 0,
"rz": 0
}, {
"rx": 0,
"ry": Math.PI / 2,
"rz": 0
}]
},
"elements": [{
"e_type": "box",
"h": 100,
"w": 50,
"d": 2,
"x": -24,
"y": 0,
"z": 0,
"rx": 0,
"ry": 0,
"rz": 0,
"textures": ["textures/drewno.jpg", "textures/drewno.jpg", "textures/drewno.jpg", "textures/drewno.jpg", "textures/drewno.jpg", "textures/drewno.jpg"]
}]
}
fragment_en.xml（上述片段的布局）
public class EnFragment extends Fragment {
private TestAdapter dbHelper;
private myCursorAdapter dataAdapter;
public EnFragment() {
// Required empty public constructor
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dbHelper = new TestAdapter(getContext());
dbHelper.createDatabase();
dbHelper.open();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_en, container, false);
setListView(view);
return view;
}
private void setListView(View view) {
Cursor cursor = dbHelper.getAllWord("enDic");
String[] columns = new String[]{
"word",
"definition",
"_id",
"favourite"
};
int[] to = new int[]{
R.id.txt_word,
R.id.txt_def,
R.id.txt_id
};
dataAdapter = new myCursorAdapter(
getContext(), en_word_row,
cursor,
columns,
to,
0);
Button btnSubmitEng = (Button) view.findViewById(R.id.btnSubmitEng);
final ListView listView = (ListView) view.findViewById(R.id.listView);
listView.setAdapter(dataAdapter);
listView.setEmptyView(btnSubmitEng);
listView.setFastScrollEnabled(true);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Cursor cursor = (Cursor) listView.getItemAtPosition(position);
final String word = cursor.getString(cursor.getColumnIndexOrThrow("word"));
Toast.makeText(getContext(), word, Toast.LENGTH_SHORT).show();
}
});
}
public void textSearch(String searchTxt){
String newStr = searchTxt.replace(" ","");
dataAdapter.getFilter().filter(newStr);
dataAdapter.setFilterQueryProvider(new FilterQueryProvider() {
public Cursor runQuery(CharSequence constraint) {
return dbHelper.getWordByName("enDic",constraint.toString());
}
});
}
private class myCursorAdapter extends SimpleCursorAdapter implements SectionIndexer {
private final AlphabetIndexer mAlphabetIndexer;
public myCursorAdapter(Context context, int layout,
Cursor c, String[] from, int[] to, int flags) {
super(context, layout, c, from, to, flags);
mAlphabetIndexer = new AlphabetIndexer(c, 1, "අBCDEFGHIJKLMNOPQRSTUVWXYZ");
}
public View newView(Context _context, Cursor _cursor, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) _context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
return inflater.inflate(en_word_row, parent, false);
}
@Override
public void bindView(View view, Context context, final Cursor cursor) {
super.bindView(view, context, cursor);
final ImageButton imgFav = (ImageButton) view.findViewById(R.id.img_fav);
final String _id = cursor.getString(cursor.getColumnIndex("_id"));
final Integer fav = Integer
.valueOf(cursor.getString(cursor.getColumnIndex("favourite")));
if (fav == 1)
imgFav.setImageResource(R.drawable.fav_on);
else
imgFav.setImageResource(R.drawable.fav_off);
imgFav.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (dbHelper.isFavourite("enDic", _id)){
imgFav.setImageResource(R.drawable.fav_off);
dbHelper.favUpdate("enDic", _id,0);
}
else{
imgFav.setImageResource(R.drawable.fav_on);
dbHelper.favUpdate("enDic", _id,1);
}
}
});
}
@Override
public Object[] getSections() {
return mAlphabetIndexer.getSections();
}
@Override
public int getPositionForSection(int sectionIndex) {
return mAlphabetIndexer.getPositionForSection(sectionIndex);
}
@Override
public int getSectionForPosition(int position) {
return mAlphabetIndexer.getSectionForPosition(position);
}
}
}
en_word_row.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.sldroid.mecdic_v21.fragment.EnFragment"
android:orientation="vertical">
<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="@android:color/transparent"
android:listSelector="@android:color/transparent"
android:scrollbarStyle="outsideOverlay"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Submit new word"
android:layout_marginTop="55dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:id="@+id/btnSubmitEng"/>
</LinearLayout>
TestAdapter的方法
<LinearLayout
android:id="@+id/cardView"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:descendantFocusability="blocksDescendants">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:baselineAligned="false"
android:paddingLeft="20dp"
android:paddingRight="20dp">
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="3"
android:paddingTop="10dp"
android:paddingBottom="10dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="25dp"
android:orientation="horizontal">
<TextView
android:id="@+id/txt_word"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Word"
android:textSize="18dp"
android:textColor="#424242"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="@+id/txt_def"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="definition"
android:textSize="10dp"
android:paddingTop="5dp"
android:paddingLeft="10dp"
android:textColor="#FF757575"
android:lines="1"/>
</LinearLayout>
<TextView
android:id="@+id/txt_id"
android:layout_width="0dp"
android:layout_height="0dp"
android:visibility="invisible"/>
</LinearLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_weight="0.5">
<ImageButton
android:id="@+id/img_fav"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/fav_off"
android:scaleType="centerInside"
android:layout_gravity="center"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true"
style="@style/Base.Widget.AppCompat.Button.Borderless"/>
</RelativeLayout>
</LinearLayout>
</LinearLayout>
答案 0 :(得分：0)
应该在doInBackground方法中调用GetAllWord和getWordByName，并在postExecute中更新你的适配器。
private class GetAllWord extends AsyncTask<Object, Object, Cursor> {
@Override
protected Cursor doInBackground(Object... params) {
return GetAllWord("your text");
}
@Override
protected void onPostExecute(Cursor result) {
if (result != null) {
//update the adapter with the result
}
}
}