我有一个ListView
使用AcitivityA
名为. 适配器保存来自SimpleCursorAdapter
RecipeAdapter
SQLite
EditText
顶部有一个视图ListView
,用于在用户搜索食谱时过滤列表视图。当用户单击过滤后的项目时ListView
,ActivityB
启动。
这一切都完美无缺。但是,当用户按下后退按钮恢复ActivityB
时,我收到以下错误。
java.lang.IllegalStateException:
trying to requery an already closed cursor android.database.sqlite.SQLiteCursor@418af170
我解决问题的尝试:
- 将代码从 复制
onCreate()
到onResume
方法。 - 添加
c.requery()
到onResume()
方法 - 添加
db.close
到onDestroy()
方法
谁能帮我解决我的问题?
这是我的代码:
在 中onCreate
,cursor
填充ListView
使用c.getCursor
,当用户ListView
通过过滤时EditText
,c.getFilterCursor
使用 。
public class RecipeActivity extends SherlockListActivity {
private DBHelper db = null;
private Cursor c = null;
private RecipeAdapter adapter = null;
ListView listContent;
private EditText filterText = null;
@SuppressWarnings("deprecation")
@Override
public void onCreate(Bundle savedInstanceState) {
try {
super.onCreate(savedInstanceState);
setContentView(R.layout.filter_list);
filterText = (EditText) findViewById(R.id.search_box);
filterText.addTextChangedListener(filterTextWatcher);
ListView listContent = getListView();
db = new DBHelper(this);
db.createDataBase();
db.openDataBase();
c = db.getCursor();
adapter = new RecipeAdapter(c);
listContent.setAdapter(adapter);
adapter.setFilterQueryProvider(new FilterQueryProvider() {
public Cursor runQuery(CharSequence constraint) {
// Search for states whose names begin with the specified letters.
c = db.getFilterCursor(constraint);
return c;
}
});
startManagingCursor(c);
} catch (IOException e) {
e.printStackTrace();
}
}
private TextWatcher filterTextWatcher = new TextWatcher() {
public void afterTextChanged(Editable s) {
}
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
public void onTextChanged(CharSequence s, int start, int before,
int count) {
adapter.getFilter().filter(s);
}
};
RecipeAdapter 内部类
class RecipeAdapter extends CursorAdapter {
@SuppressWarnings("deprecation")
public RecipeAdapter(Cursor c) {
super(RecipeActivity.this, c);
}
public void bindView(View row, Context arg1, Cursor arg2) {
RecipeHolder holder = (RecipeHolder) row.getTag();
holder.populateFrom(c, db);
}
public View newView(Context arg0, Cursor arg1, ViewGroup arg2) {
LayoutInflater inflater = getLayoutInflater();
View row = inflater.inflate(R.layout.reciperow, arg2, false);
RecipeHolder holder = new RecipeHolder(row);
row.setTag(holder);
return (row);
}
static class RecipeHolder {
public TextView id = null;
private TextView name = null;
private TextView desc = null;
private TextView preptime = null;
private TextView cooktime = null;
private TextView serves = null;
private TextView calories = null;
private TextView fat = null;
private TextView fav = null;
RecipeHolder(View row) {
id = (TextView) row.findViewById(R.id.id);
name = (TextView) row.findViewById(R.id.recipe);
desc = (TextView) row.findViewById(R.id.desc);
preptime = (TextView) row.findViewById(R.id.preptime);
cooktime = (TextView) row.findViewById(R.id.cooktime);
serves = (TextView) row.findViewById(R.id.serving);
calories = (TextView) row.findViewById(R.id.calories);
fat = (TextView) row.findViewById(R.id.fat);
fav = (TextView) row.findViewById(R.id.fav);
}
void populateFrom(Cursor c, DBHelper r) {
id.setText(r.getId(c));
name.setText(r.getRecipe(c));
name.setTextColor(Color.parseColor("#CCf27c22"));
desc.setText(r.getDesc(c));
preptime.setText(r.getPrepTime(c) + ". ");
cooktime.setText(r.getCookTime(c) + " mins");
serves.setText(r.getServes(c));
calories.setText(r.getCalories(c));
fat.setText(r.getFat(c));
fav.setText(r.getFav(c));
DBHelper 类中的 getCursor() 和 getFilterCursor() 代码
public Cursor getCursor() {
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setTables(DATABASE_TABLE);
String[] columns = new String[] { KEY_ROWID, RECIPE, DESC, PREPTIME,
COOKTIME, SERVES, CALORIES, FAT, CATEGORY, FAV };
Cursor myCursor = queryBuilder.query(myDataBase, columns, null, null,
null, null, RECIPE + " ASC");
return myCursor;
}
public Cursor getFilterCursor(CharSequence constraint) {
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setTables(DATABASE_TABLE);
String[] columns = new String[] { KEY_ROWID, RECIPE, DESC, PREPTIME,
COOKTIME, SERVES, CALORIES, FAT, CATEGORY, FAV };
if (constraint == null || constraint.length() == 0) {
// Return the full list
return queryBuilder.query(myDataBase, columns, null, null, null,
null, RECIPE + " ASC");
} else {
String value = "%" + constraint.toString() + "%";
return myDataBase.query(DATABASE_TABLE, columns, "RECIPE like ? ",
new String[] { value }, null, null, null);
}
}
完整的日志
FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to resume activity {ttj.android.quorn/ttj.android.quorn.RecipeActivity}:
java.lang.IllegalStateException: trying to requery an already closed cursor android.database.sqlite.SQLiteCursor@41954658
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2456)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2484)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1185)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4507)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalStateException: trying to requery an already closed cursor android.database.sqlite.SQLiteCursor@41954658
at android.app.Activity.performRestart(Activity.java:4508)
at android.app.Activity.performResume(Activity.java:4531)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2446)