我正在创建一个小型 Financecontrol-App。现在我面临一个问题，我认为不打手机就无法解决=D
我得到了一个带有从 Android 模板创建的 ViewPager 的 Activity。我有 3 个标签。第二个和第三个选项卡使用相同的 Fragment-Class。这是选项卡的片段：
在 AccountActivity 中：
@Override
public Fragment getItem(int position) {
Fragment fragment = null;
Bundle args = new Bundle();
switch (position) {
case POSITION_OVERVIEW:
fragment = new OverviewSectionFragment();
break;
case POSITION_INCOME:
args.putString("flag", TransactionSectionFragment.INCOME);
fragment = new TransactionSectionFragment();
fragment.setArguments(args);
break;
case POSITION_OUTGO:
args.putString("flag", TransactionSectionFragment.OUTGO);
fragment = new TransactionSectionFragment();
fragment.setArguments(args);
break;
}
return fragment;
}
片段本身看起来像这样：
public class TransactionSectionFragment extends Fragment {
OnDataChangedListener mCallback;
public interface OnDataChangedListener {
public void onDataChanged(int rnd);
}
// Private variables for IncomeSectionFragment
private FinanceDataSource datasource;
private ListView transactionList;
private CustomFinanceListAdapter adapter;
private String flag;
private Button newTran;
// public constants
public static final String INCOME = "i";
public static final String OUTGO = "o";
// Variables for Contextmenu
private static final int DETAILS_OPTION = Menu.FIRST;
private static final int DELETE_OPTION = DETAILS_OPTION + 1;
public TransactionSectionFragment() {
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallback = (OnDataChangedListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnDataChangedListener");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(
R.layout.fragment_account_transactions, container, false);
return rootView;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
newTran = (Button) getView().findViewById(R.id.new_entry_btn);
transactionList = (ListView) this.getView().findViewById(
R.id.transactionlist);
flag = getArguments().getString("flag");
datasource = new FinanceDataSource(getActivity());
datasource.open();
updateList();
registerForContextMenu(transactionList);
transactionList
.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
Transaction tran = (Transaction) transactionList
.getItemAtPosition(position);
showTransactionDetails(tran);
}
});
newTran.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
datasource.insertSomeTransactions();
updateList();
}
});
}
@Override
public void onResume() {
datasource.open();
super.onResume();
}
@Override
public void onPause() {
datasource.close();
super.onPause();
}
private void showTransactionDetails(Transaction tran) {
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
if (v.getId() == R.id.transactionlist) {
menu.setHeaderTitle("Optionen ");
menu.add(Menu.NONE, DETAILS_OPTION, 0, "Details");
menu.add(Menu.NONE, DELETE_OPTION, 1, "Eintrag löschen");
}
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item
.getMenuInfo();
Transaction tran = (Transaction) transactionList
.getItemAtPosition(info.position);
switch (item.getItemId()) {
case DETAILS_OPTION:
showMsg(tran.getID() + "");
break;
case DELETE_OPTION:
try {
datasource.deleteTransaction(tran);
updateList();
showMsg("Entry deleted!");
} catch (Exception e) {
Log.i("Exception", e.getMessage());
}
break;
}
return true;
}
// Show Toast
private void showMsg(String message) {
Toast msg = Toast.makeText(getActivity(), message, Toast.LENGTH_LONG);
msg.show();
}
private void updateList() {
adapter = new CustomFinanceListAdapter(
datasource.getAllTransactions(flag), getActivity());
transactionList.setAdapter(adapter);
mCallback.onDataChanged(new Random().nextInt());
}
}
现在的问题是：代表收入的第一个 Fragment 填充了来自标有“i”的 sqlite 数据库的数据。第二个片段被标记为“o”。这工作得很好。列表视图中的每个条目都代表一个事务 ---> 参见此处：
public class Transaction {
// private variables
int id;
String date;
double value;
String desc;
String flag;
// Empty constructor
public Transaction() {
}
// constructor
public Transaction(String date, double value, String desc, String flag) {
this.date = date;
this.value = value;
this.desc = desc;
this.flag = flag;
}
// constructor
public Transaction(int id, String date, double value, String desc,
String flag) {
this.id = id;
this.date = date;
this.value = value;
this.desc = desc;
this.flag = flag;
}
// get name
public int getID() {
return this.id;
}
// get name
public String getDate() {
return this.date;
}
// set name
public void setDate(String date) {
this.date = date;
}
// get value
public double getValue() {
return this.value;
}
// set value
public void setValue(double value) {
this.value = value;
}
// get description
public String getDesc() {
return this.desc;
}
// set description
public void setDesc(String desc) {
this.desc = desc;
}
// get flag
public String getFlag() {
return this.flag;
}
// set flag
public void setFlag(String flag) {
this.flag = flag;
}
@Override
public String toString() {
return this.getDesc();
}
}
通过长按一个列表项，我得到了事务的 ID，它应该与数据库中的相同（自动增量主键等）。所以它应该是独一无二的。但是 outgo-list 上的第一项与 income-list 上的第一项具有相同的 id。通过从收入列表中删除一个项目，结果列表中的最后一个项目会得到一个 outofboundexception，因为理论上应该比显示的少一个。但是结果列表并不像收入那样刷新自己，更像是具有不同值的收入的“副本”。
希望你能解决我的问题......如果你需要更多代码，请告诉我=）
编辑 1：这是创建表的 SQL 语句：
USERS_TABLE_CREATE = "CREATE TABLE "
+ TABLE_FINANCES + " (" + COLUMN_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL," + COLUMN_DATE
+ " DATETIME NOT NULL," + COLUMN_VALUE + " REAL NOT NULL," + COLUMN_DESC
+ " NVARCHAR(255)," + COLUMN_FLAG + " NVARCHAR(1) NOT NULL);";
数据集本身看起来像：
(id, date, value, description, flag) ==> ex1: (2, 23.08.2013, 33.33, "tip", "i") 用于收入数据集和 ex2: (3, 23.08.2013, 12.12, "票”，“o”）用于结果数据集
现在一些图片：第一个条目的getID（）的收入屏幕-> http://i.imgur.com/kfCkjGr.png第一个条目 的getID（）的输出屏幕-> http://i.imgur.com /tOdoSqb.png
编辑 2：我在以下帮助下解决了问题： ViewPager 中的错误片段接收 onContextItemSelected 调用
你必须用这个包装 onContextItemSelected 调用，因为 fragmentmanager 需要第一个为 contextmenu 返回 true 的可用片段，而不是你实际使用的片段
if (getUserVisibleHint()) {
// Handle menu events and return true
} else
return false; // Pass the event to the next fragment
}