来自SQLite的Android游标在方法调用上崩溃

Question

晚上好！

我想从我刚刚在我的android项目中创建的SQLite数据库读取。我创建数据库并输入数据没有任何问题（我认为）。我查询数据库获取没有任何运行时complanints数据，我得到的方法调用返回的游标。但是当我尝试使用游标时，应用程序崩溃。 “主题与未捕获的异常（组= 0x416b72a0）退出。

这是我试图运行。光标的的toString工作正常的代码。

TransactionSQLOH helper = new TransactionSQLOH(context, getDbName(yearS, monthS)); 
    SQLiteDatabase db = helper.getReadableDatabase(); 
    String[] columns = {"amount", "label", "year", "month", "day", "categoryID", "type", "ID", "time"}; 
    Cursor cursor = db.query(TransactionSQLOH.TABLE_NAME, columns, null, null, null, null, null); 
    System.out.println(db); 
    helper.close(); 
    System.out.println("Transaction_Check3.1"); 
    if (cursor == null){ 
     return null; 
    } 
    System.out.println("Transaction_Check3.2"); 
    System.out.println(cursor); 
    int test = cursor.getCount(); 
    System.out.println("Transaction_Check3.3"); 
    Transaction[] result = new Transaction[10]; 

我得到errror在行

int test = cursor.getCount(); 

帮助将不胜感激:)

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02-19 21:08:11.273: I/System.out(21558): Transaction_Check1 
    02-19 21:08:11.283: I/System.out(21558): Transaction_Check2 
    02-19 21:08:11.283: I/System.out(21558): SQLiteDatabase:      /data/data/com.SverkerSbrg.Spendo/databases/transactions_201301 
    02-19 21:08:11.283: I/System.out(21558): Transaction_Check3 
    02-19 21:08:11.288: I/System.out(21558): Transaction_Check3.1 
    02-19 21:08:11.288: I/System.out(21558): Transaction_Check3.2 
    02-19 21:08:11.288: I/System.out(21558): android.database.sqlite.SQLiteCursor@421107d8 
    02-19 21:08:11.288: I/System.out(21558): Transaction_Check3.3 
    02-19 21:08:11.288: I/System.out(21558): Transaction_Check4 
    02-19 21:08:11.288: D/AndroidRuntime(21558): Shutting down VM 
    02-19 21:08:11.288: W/dalvikvm(21558): threadid=1: thread exiting with uncaught exception (group=0x416b72a0) 
    02-19 21:08:11.328: E/AndroidRuntime(21558): FATAL EXCEPTION: main 
    02-19 21:08:11.328: E/AndroidRuntime(21558): java.lang.IllegalStateException: Could not execute method of the activity 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.view.View$1.onClick(View.java:3704) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.view.View.performClick(View.java:4232) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.view.View$PerformClick.run(View.java:17298) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.os.Handler.handleCallback(Handler.java:615) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.os.Handler.dispatchMessage(Handler.java:92) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.os.Looper.loop(Looper.java:137) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.app.ActivityThread.main(ActivityThread.java:4921) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at java.lang.reflect.Method.invokeNative(Native Method) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at java.lang.reflect.Method.invoke(Method.java:511) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at dalvik.system.NativeStart.main(Native Method) 
    02-19 21:08:11.328: E/AndroidRuntime(21558): Caused by: java.lang.reflect.InvocationTargetException 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at java.lang.reflect.Method.invokeNative(Native Method) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at java.lang.reflect.Method.invoke(Method.java:511) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.view.View$1.onClick(View.java:3699) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  ... 11 more 
    02-19 21:08:11.328: E/AndroidRuntime(21558): Caused by: java.lang.IllegalStateException: Cannot perform this operation because the connection pool has been closed. 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteConnectionPool.throwIfClosedLocked(SQLiteConnectionPool.java:972) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteConnectionPool.waitForConnection(SQLiteConnectionPool.java:609) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteConnectionPool.acquireConnection(SQLiteConnectionPool.java:349) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteSession.acquireConnection(SQLiteSession.java:894) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteSession.executeForCursorWindow(SQLiteSession.java:834) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:62) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:143) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.sqlite.SQLiteCursor.getCount(SQLiteCursor.java:133) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.AbstractCursor.moveToPosition(AbstractCursor.java:196) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at android.database.AbstractCursor.moveToFirst(AbstractCursor.java:236) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at com.SverkerSbrg.Spendo.Datastructures.Transaction.getMonthTransaciton(Transaction.java:88) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  at com.SverkerSbrg.Spendo.MainActivity.btn2_click(MainActivity.java:43) 
    02-19 21:08:11.328: E/AndroidRuntime(21558):  ... 14 more 

Answer 1

移动：

helper.close(); 

后：

int test = cursor.getCount(); 

因为你试图对已关闭访问数据库的SQLiteOpenHelper后使用光标您购买的IllegalStateException例外。这会导致错误。