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我正在開發一個應用程序，其中我需要一個ListView，其行具有TextView，2 CheckBox和Spinner。如何讓List內的Spinner在Android中工作？
但是，我遇到了Spinner的onItemSelected()問題，因爲每次顯示每行時都會調用它。在這種方法中，我使用選定的選項更新數據庫記錄，但是由於Android會自動調用它，所以每當項目被重置時，Android都會調用它的位置爲0，並且這是數據庫中更新的值。
我已閱讀了很多有關onItemSelected()和一些黑客問題的鏈接，但它們都是在沒有ListView的情況下使用的。這裏的任何觀點？
我試圖在列表中追蹤哪些位置實際顯示以使其工作，但事實並非如此。我認爲這是因爲在Android中的回收，導致調試方法被調用Spinners已經顯示！
因此，問題是：由於用戶在顯示微調器時從Android調用中進行選擇，我如何區分實際調用onItemSelected()？
這裏是我的適配器擴展SimpleCursorAdapter的代碼。
非常感謝你提前。
public ParticipationAdapter(Context context, int layout, Cursor c, String[] from, int[] to) {
super(context, layout, c, from, to);
mActivity = (Activity)context;
ParticipationComment.ParticipationCommentManager commentManager = new ParticipationComment.ParticipationCommentManager(mActivity);
mParticipationCommentsCursor = commentManager.get();
mActivity.startManagingCursor(mParticipationCommentsCursor);
commentManager.detach();
mPositionsOfCursorIds = getPositionsOfCursorIds(mParticipationCommentsCursor);
mSpinnerPositionsDisplayed = new ArrayList<Integer>();
}
@Override
public View getView(final int participationPosition, View convertView, ViewGroup parent) {
final Cursor participationsCursor = getCursor();
mActivity.startManagingCursor(participationsCursor);
participationsCursor.moveToPosition(participationPosition);
View participationRow;
if (convertView == null) {
participationRow = LayoutInflater.from(mActivity).inflate(R.layout.participation_row_student, null);
} else {
mSpinnerPositionsDisplayed.remove((Integer)convertView.getTag());
participationRow = convertView;
}
participationRow.setTag(participationPosition);
Spinner commentSpinner = (Spinner)participationRow.findViewById(R.id.participation_comment_id_spinner);
SimpleCursorAdapter commentSpinnerAdapter = new SimpleCursorAdapter(
mActivity,
android.R.layout.simple_spinner_item,
mParticipationCommentsCursor,
new String[] {DatabaseManager.NAME},
new int[] {android.R.id.text1}
);
commentSpinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
commentSpinner.setAdapter(commentSpinnerAdapter);
long participationCommentId = participationsCursor.getLong(participationsCursor.getColumnIndex(DatabaseManager.PARTICIPATION_COMMENT_ID));
if (participationCommentId != 0) {
commentSpinner.setSelection(mPositionsOfCursorIds.get(participationCommentId));
}
commentSpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
participationsCursor.moveToPosition(participationPosition);
if (!mSpinnerPositionsDisplayed.contains(participationPosition)) {
// Android calls this method the first time a Spinner is displayed,
// to differentiate from a real user click we check if the current Spinner's position
// in the ListView is being shown
mSpinnerPositionsDisplayed.add(participationPosition);
} else {
ParticipationComment participationComment = new ParticipationComment((Cursor)parent.getItemAtPosition(position));
Participation.ParticipationManager participationManager = new Participation.ParticipationManager(mActivity);
Participation participation = new Participation(participationsCursor);
participation.setConnectionProfileParticipationCommentId(participationComment.getConnectionProfileId());
participation.setParticipationCommentId(participationComment.getIdOpenErp());
participation.setChanged(true);
participationManager.update(participation);
participationManager.detach();
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
// Not used
}
});
TextView studentName = (TextView)participationRow.findViewById(R.id.participation_student_name);
studentName.setText(participationsCursor.getString(participationsCursor.getColumnIndex(DatabaseManager.NAME)));
CheckBox expectedPresent = (CheckBox)participationRow.findViewById(R.id.participation_expected_present_value);
expectedPresent.setChecked(participationsCursor.getInt(participationsCursor.getColumnIndex(DatabaseManager.EXPECTED_PRESENT)) == 1);
CheckBox present = (CheckBox)participationRow.findViewById(R.id.participation_present_value);
present.setChecked(participationsCursor.getInt(participationsCursor.getColumnIndex(DatabaseManager.PRESENT)) == 1);
return participationRow;
}
非常感謝您的回答！明天我會嘗試並向你說點什麼！但是我會使用'public AlertDialog.Builder setCursor（Cursor cursor，DialogInterface.OnClickListener listener，String labelColumn）'代替，因爲我在db表中有原始數據。我認爲，通過這種方法，我將能夠讓用戶不選擇任何選項，這是我實際需要的，並且不可能使用微調器。 – Caumons 2012-04-12 16:58:19
@卡路里..祝你好運.. – ngesh 2012-04-13 05:28:15
非常感謝，非常感謝！按照您的建議，我最終在ListView中使用按鈕和alertDialog實現了選擇。這很好用！我在對話框中使用了'setSingleChoiceItems（）'方法，因爲它允許您定義默認選擇。我已upvoted並接受你的答案給你+25代表！ :) – Caumons 2012-04-16 11:31:38