Question

我在我的sqlite助手类上有这个：

public String listaProdutoDeUmaProposta(String proposta) {

    String sql = "SELECT produto FROM propostas " +
    " WHERE _id =" + proposta;
    String x = "";
    Cursor c = db.rawQuery(sql, null);
    if (c != null) {
        if (c.moveToFirst()) {
            c.moveToFirst();
            x = c.getString(0); 
        }   
    }
    //c.close();
    return x;
}

我在活动A上使用它（在onCreate里面）：

    db = new repositorio(Dados.this);
    db.open();
    produto = db.listaProdutoDeUmaProposta(PROPOSTA);
    if ("XXX".equals(produto)) {
        //code code code
    }
    db.close()

我在活动A上使用它，如果转到活动B并按下后退按钮，应用程序强制关闭，它表示光标已经关闭。我该如何解决这个问题？

错误

W/SQLiteCursor(1088): requery() failed database /data/data/ace.cice/databases/combinedxxi (conn# 0) already closed
W/SQLiteCursor(1088): java.lang.IllegalStateException: database /data/data/ace.cice/databases/combinedxxi (conn# 0) already closed
W/SQLiteCursor(1088):   at android.database.sqlite.SQLiteDatabase.verifyDbIsOpen(SQLiteDatabase.java:2123)
W/SQLiteCursor(1088):   at android.database.sqlite.SQLiteDatabase.getDbConnection(SQLiteDatabase.java:2448)
W/SQLiteCursor(1088):   at android.database.sqlite.SQLiteDatabase.getDatabaseHandle(SQLiteDatabase.java:2429)
W/SQLiteCursor(1088):   at android.database.sqlite.SQLiteCursor.requery(SQLiteCursor.java:412)
W/SQLiteCursor(1088):   at android.app.Activity.performRestart(Activity.java:4393)
W/SQLiteCursor(1088):   at android.app.ActivityThread.performRestartActivity(ActivityThread.java:2652)
W/SQLiteCursor(1088):   at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:163)
W/SQLiteCursor(1088):   at android.app.LocalActivityManager.dispatchResume(LocalActivityManager.java:518)
W/SQLiteCursor(1088):   at android.app.ActivityGroup.onResume(ActivityGroup.java:58)
W/SQLiteCursor(1088):   at ace.cice.DadosApoliceTabs.onResume(DadosApoliceTabs.java:163)
W/SQLiteCursor(1088):   at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1153)
W/SQLiteCursor(1088):   at android.app.Activity.performResume(Activity.java:4428)
W/SQLiteCursor(1088):   at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2217)
W/SQLiteCursor(1088):   at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2255)
W/SQLiteCursor(1088):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1028)
W/SQLiteCursor(1088):   at android.os.Handler.dispatchMessage(Handler.java:99)
W/SQLiteCursor(1088):   at android.os.Looper.loop(Looper.java:132)
W/SQLiteCursor(1088):   at android.app.ActivityThread.main(ActivityThread.java:4025)
W/SQLiteCursor(1088):   at java.lang.reflect.Method.invokeNative(Native Method)
W/SQLiteCursor(1088):   at java.lang.reflect.Method.invoke(Method.java:491)
W/SQLiteCursor(1088):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
W/SQLiteCursor(1088):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
W/SQLiteCursor(1088):   at dalvik.system.NativeStart.main(Native Method)
D/AndroidRuntime(1088): Shutting down VM W/dalvikvm(1088): threadid=1: thread exiting with uncaught exception (group=0x40014760)
E/AndroidRuntime(1088): FATAL EXCEPTION: main 
E/AndroidRuntime(1088): java.lang.RuntimeException: Unable to resume activity {ace.cice/ace.cice.DadosApoliceTabs}: java.lang.IllegalStateException: trying to requery an already closed cursor 
E/AndroidRuntime(1088):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2227) 
E/AndroidRuntime(1088):     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2255) 
E/AndroidRuntime(1088):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1028) 
E/AndroidRuntime(1088):     at android.os.Handler.dispatchMessage(Handler.java:99) 
E/AndroidRuntime(1088):     at android.os.Looper.loop(Looper.java:132) 
E/AndroidRuntime(1088):     at android.app.ActivityThread.main(ActivityThread.java:4025) 
E/AndroidRuntime(1088):     at java.lang.reflect.Method.invokeNative(Native Method) 
E/AndroidRuntime(1088):     at java.lang.reflect.Method.invoke(Method.java:491) 
E/AndroidRuntime(1088):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) 
E/AndroidRuntime(1088):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) 
E/AndroidRuntime(1088):     at dalvik.system.NativeStart.main(Native Method) 
E/AndroidRuntime(1088): Caused by: java.lang.IllegalStateException: trying to requery an already closed cursor 
E/AndroidRuntime(1088):     at android.app.Activity.performRestart(Activity.java:4394) 
E/AndroidRuntime(1088):     at android.app.ActivityThread.performRestartActivity(ActivityThread.java:2652) 
E/AndroidRuntime(1088):     at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:163) 
E/AndroidRuntime(1088):     at android.app.LocalActivityManager.dispatchResume(LocalActivityManager.java:518) 
E/AndroidRuntime(1088):     at android.app.ActivityGroup.onResume(ActivityGroup.java:58) 
E/AndroidRuntime(1088):     at ace.cice.DadosApoliceTabs.onResume(DadosApoliceTabs.java:163) 
E/AndroidRuntime(1088):     at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1153) 
E/AndroidRuntime(1088):     at android.app.Activity.performResume(Activity.java:4428) 
E/AndroidRuntime(1088):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2217) 
E/AndroidRuntime(1088):     ... 10 more

的onResume：

@Override
public void onResume() {
    System.out.println("Dados Apolice Tabs ON RESUME");
    db = new repositorio(Dados.this);
    db.open();
    produto = db.listaProdutoDeUmaProposta(PROPOSTA);
    db.close();
        super.onResume();   
}

我将A中的活动B称为：

I = new Intent("ace.cice.AconselhamentoCliente");
EXTRAS = new Bundle();
EXTRAS.putString("proposta", PROPOSTA);
I.putExtras(EXTRAS);
startActivityForResult(I, request_Code);

Android关闭游标

0 个答案: