我想使用 SimpleCursorAdapter 从我的 ListView 中删除一个数据库条目。每个列表项中都有一个用于删除条目的按钮。但是,当我单击列表视图中的删除按钮时,每次列表中的最后一项都会被删除。
https://www.dropbox.com/s/inhdfcyxkrzrihs/problem.png
自定义 SimpleCursorAdapter:
public class BookmarksAdapter extends SimpleCursorAdapter {
private static String[] fromColumns = { Bookmarks.NAME, Bookmarks.PATH };
private static int[] toViews = { R.id.title, R.id.path };
private Cursor mCursor;
private Context mContext;
private LayoutInflater mLayoutInflater;
private int mIdIndex, mTitleIndex, mPathIndex;
public BookmarksAdapter(Context context, Cursor c, int i) {
super(context, R.layout.item_bookmark, c, fromColumns, toViews, i);
this.mLayoutInflater = LayoutInflater.from(context);
this.mContext = context;
this.mCursor = c;
this.mIdIndex = c.getColumnIndexOrThrow(Bookmarks._ID);
this.mTitleIndex = c.getColumnIndexOrThrow(Bookmarks.NAME);
this.mPathIndex = c.getColumnIndexOrThrow(Bookmarks.PATH);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (mCursor.moveToPosition(position)) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = mLayoutInflater.inflate(R.layout.item_bookmark,
parent, false);
viewHolder = new ViewHolder(convertView);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.title.setText(mCursor.getString(mTitleIndex));
viewHolder.path.setText(mCursor.getString(mPathIndex));
viewHolder.remove.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO fix delete
Uri deleteUri = ContentUris.withAppendedId(
Bookmarks.CONTENT_URI, mCursor.getInt(mIdIndex));
mContext.getContentResolver().delete(deleteUri, null, null);
update(mCursor);
}
});
}
return convertView;
}
public void createBookmark(Activity a, String path, String key) {
Cursor c = a.getContentResolver().query(Bookmarks.CONTENT_URI,
new String[] { Bookmarks._ID }, Bookmarks.PATH + "=?",
new String[] { path }, null);
if (!c.moveToFirst()) {
ContentValues values = new ContentValues();
values.put(Bookmarks.NAME, String.valueOf(key));
values.put(Bookmarks.PATH, path);
a.getContentResolver().insert(Bookmarks.CONTENT_URI, values);
Toast.makeText(a, R.string.bookmarkadded, Toast.LENGTH_SHORT)
.show();
} else {
Toast.makeText(a, R.string.bookmarkexist, Toast.LENGTH_SHORT)
.show();
}
update(c);
}
@SuppressWarnings("deprecation")
private void update(Cursor c) {
c.requery();
notifyDataSetChanged();
}
private class ViewHolder {
ImageButton remove;
TextView title;
TextView path;
ViewHolder(View v) {
title = (TextView) v.findViewById(R.id.title);
path = (TextView) v.findViewById(R.id.path);
remove = (ImageButton) v.findViewById(R.id.imageButton_remove);
}
}
}
ContentProvider 类的一部分:
@Override
public int delete(Uri uri, String arg1, String[] arg2) {
int count = 0;
switch (uriMatcher.match(uri)) {
case BOOKMARKS:
count = db.delete(TB_NAME, arg1, arg2);
break;
case BOOKMARK_ID:
String id = uri.getPathSegments().get(0);
count = db.delete(TB_NAME,
_ID
+ " = "
+ id
+ (!TextUtils.isEmpty(arg1) ? " AND (" + arg1 + ')'
: ""), arg2);
break;
default:
throw new IllegalArgumentException("Unknown URI " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return count;
}