java - 将数据保存到黑莓内存中

Question

我有一个应用程序，当我们单击“开始”时，它会显示一个测试屏幕。现在我添加了一个恢复测试按钮，并希望从退出位置显示问题。为此，我想将问题保存到内存中，以便我可以从那里获取并显示它。我正在编写代码，请帮忙

package com.firstBooks.series.ui.screens;

import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.FieldChangeListener;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Manager;
import net.rim.device.api.ui.MenuItem;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.component.LabelField;
 import net.rim.device.api.ui.component.Menu;
import net.rim.device.api.ui.component.NullField;
import net.rim.device.api.ui.container.HorizontalFieldManager;

 import net.rim.device.api.ui.container.VerticalFieldManager;
import java.lang.String;
import com.firstBooks.series.AppConfig;
import com.firstBooks.series.db.DBMain;
import com.firstBooks.series.db.Question;
import com.firstBooks.series.db.parser.XMLParser;
import com.firstBooks.series.ui.UIinitialize;
import com.firstBooks.series.ui.managers.TopManager;
import com.vensi.api.ImgButtonField;

public class TestScreen extends ScreenManager implements AppConfig{

TopManager topManager = null;
VerticalFieldManager middleManager = null;
HorizontalFieldManager manager = null;
ImgButtonField A, B, C, D;
//static PersistentObject Store;
static int quesNum[];
int quesNumber;//quesnumberTest[];
LabelField question1, blank, choice1Label, choice2Label, choice3Label,
        choice4Label;
FieldChangeListener checkAnswerListenerA, checkAnswerListenerB,
        checkAnswerListenerC, checkAnswerListenerD;

public TestScreen() {
    super();
    drawScreen();
}
//static {
    //Store = PersistentStore.getPersistentObject(0x3097b5a0b70e028fL);
//}
public void drawScreen() {

    topManager = new TopManager(newTestButton, 0);

    middleManager = new VerticalFieldManager(
            VerticalFieldManager.VERTICAL_SCROLL
                    | VerticalFieldManager.VERTICAL_SCROLLBAR
                    | VerticalFieldManager.USE_ALL_WIDTH
                    | Field.FIELD_HCENTER) {
        protected void sublayout(int maxWidth, int maxHeight) {
            // maxwidth reduced by 15 to get padding along the edges
            super.sublayout(maxWidth - 15, maxHeight - 10);

            if (UIinitialize.displayType == Device_Storm) {
                setExtent(maxWidth - 15, 347);
            } else if (UIinitialize.displayType == Device_Tour) {
                setExtent(maxWidth - 15, 263);
            } else if (UIinitialize.displayType == Device_Curve) {
                setExtent(maxWidth - 10, 165);
            }

        }
    };

    A = new ImgButtonField(buttonABkGrndDown, buttonABkGrnd,
            Field.FOCUSABLE | Field.FIELD_HCENTER);
    B = new ImgButtonField(buttonBBkGrndDown, buttonBBkGrnd,
            Field.FOCUSABLE | Field.FIELD_HCENTER);
    C = new ImgButtonField(buttonCBkGrndDown, buttonCBkGrnd,
            Field.FOCUSABLE | Field.FIELD_HCENTER);
    D = new ImgButtonField(buttonDBkGrndDown, buttonDBkGrnd,
            Field.FOCUSABLE | Field.FIELD_HCENTER);


        manager = new HorizontalFieldManager(Manager.NO_HORIZONTAL_SCROLL
            | Manager.NO_VERTICAL_SCROLL | Field.USE_ALL_WIDTH
            | Field.USE_ALL_HEIGHT) {
        protected void sublayout(int maxWidth, int maxHeight) {

             if (UIinitialize.displayType == Device_Storm) {
                layoutChild(A, buttonABkGrnd.getWidth(), buttonABkGrnd
                        .getHeight());
                setPositionChild(A, 25, 9);

                layoutChild(B, buttonBBkGrnd.getWidth(), buttonBBkGrnd
                        .getHeight());
                setPositionChild(B, 115, 9);

                layoutChild(C, buttonCBkGrnd.getWidth(), buttonCBkGrnd
                        .getHeight());
                setPositionChild(C, 205, 9);

                layoutChild(D, buttonDBkGrnd.getWidth(), buttonDBkGrnd
                        .getHeight());
                setPositionChild(D, 295, 9);

            } else if (UIinitialize.displayType == Device_Tour) {
                layoutChild(A, buttonABkGrnd.getWidth(), buttonABkGrnd
                        .getHeight());
                setPositionChild(A, 41, 9);

                layoutChild(B, buttonBBkGrnd.getWidth(), buttonBBkGrnd
                        .getHeight());
                setPositionChild(B, 161, 9);

                layoutChild(C, buttonCBkGrnd.getWidth(), buttonCBkGrnd
                        .getHeight());
                setPositionChild(C, 281, 9);

                layoutChild(D, buttonDBkGrnd.getWidth(), buttonDBkGrnd
                        .getHeight());
                setPositionChild(D, 401, 9);
            } else if (UIinitialize.displayType == Device_Curve) {
                layoutChild(A, buttonABkGrnd.getWidth(), buttonABkGrnd
                        .getHeight());
                setPositionChild(A, 33, 19);

                layoutChild(B, buttonBBkGrnd.getWidth(), buttonBBkGrnd
                        .getHeight());
                setPositionChild(B, 107, 19);

                layoutChild(C, buttonCBkGrnd.getWidth(), buttonCBkGrnd
                        .getHeight());
                setPositionChild(C, 182, 19);

                layoutChild(D, buttonDBkGrnd.getWidth(), buttonDBkGrnd
                        .getHeight());
                setPositionChild(D, 257, 19);
            }

            setExtent(maxWidth, maxHeight);
        }

        protected void paint(Graphics g) {
            super.paint(g);
        }
    };

    String title = "";

    quesNumber = DBMain.getQuestionNumber();
    System.out.println("the value of QUESNUMBER IS:"+quesNumber);
    DBMain.curQuestion = (Question) XMLParser.questionList
            .elementAt(quesNumber);
    title = DBMain.curQuestion.getTitle();

    String BlankSpace = "  ";
    String choice1 = "A.  " + DBMain.curQuestion.getChoice1() + "\n" + "  ";
    String choice2 = "B.  " + DBMain.curQuestion.getChoice2() + "\n" + "  ";
    String choice3 = "C.  " + DBMain.curQuestion.getChoice3() + "\n" + "  ";
    String choice4 = "D.  " + DBMain.curQuestion.getChoice4() + "\n" + "  ";

    question1 = new LabelField(title);
    question1.setFont(myFontBoldSmall());

    blank = new LabelField(BlankSpace);
    blank.setFont(myFontBoldSmall());

    choice1Label = new LabelField(choice1);
    choice1Label.setFont(myFontPlainSmall());
    choice2Label = new LabelField(choice2);
    choice2Label.setFont(myFontPlainSmall());
    choice3Label = new LabelField(choice3);
    choice3Label.setFont(myFontPlainSmall());
    choice4Label = new LabelField(choice4);
    choice4Label.setFont(myFontPlainSmall());

    DBMain.answer = DBMain.curQuestion.getAnswer();
    //synchronized (Store) {
        //Store.setContents(quesNumber+"");

        //Store.commit();

     //}

    checkAnswerListenerA = new FieldChangeListener() {

        public void fieldChanged(Field field, int context) {
            DBMain.selectedAnswer = "A";
            UiApplication.getUiApplication().pushScreen(new AnswerScreen());
            UiApplication.getUiApplication().popScreen(getScreen());

        }
    };
    A.setChangeListener(checkAnswerListenerA);
    checkAnswerListenerB = new FieldChangeListener() {

        public void fieldChanged(Field field, int context) {
            DBMain.selectedAnswer = "B";
            UiApplication.getUiApplication().pushScreen(new AnswerScreen());
            UiApplication.getUiApplication().popScreen(getScreen());
        }
    };
    B.setChangeListener(checkAnswerListenerB);

    checkAnswerListenerC = new FieldChangeListener() {

        public void fieldChanged(Field field, int context) {
            DBMain.selectedAnswer = "C";
            UiApplication.getUiApplication().pushScreen(new AnswerScreen());
            UiApplication.getUiApplication().popScreen(getScreen());
        }
    };
    C.setChangeListener(checkAnswerListenerC);

    checkAnswerListenerD = new FieldChangeListener() {

        public void fieldChanged(Field field, int context) {
            DBMain.selectedAnswer = "D";
            UiApplication.getUiApplication().pushScreen(new AnswerScreen());
            UiApplication.getUiApplication().popScreen(getScreen());
        }
    };
    D.setChangeListener(checkAnswerListenerD);
    /*A.setChangeListener(checkAnswerListenerA);
    B.setChangeListener(checkAnswerListenerB);
    C.setChangeListener(checkAnswerListenerC);
    D.setChangeListener(checkAnswerListenerD);*/

    manager.add(new NullField(Field.FOCUSABLE));
    manager.add(A);
    manager.add(B);
    manager.add(C);
    manager.add(D);
    manager.add(new NullField(Field.FOCUSABLE));

    middleManager.add(question1);
    middleManager.add(new NullField(Field.FOCUSABLE));
    middleManager.add(blank);
    middleManager.add(choice1Label);
    middleManager.add(new NullField(Field.FOCUSABLE));
    middleManager.add(choice2Label);
    middleManager.add(new NullField(Field.FOCUSABLE));
    middleManager.add(choice3Label);
    middleManager.add(new NullField(Field.FOCUSABLE));
    middleManager.add(choice4Label);

    add(topManager);
    add(middleManager);
    add(manager);
}

protected void makeMenu(Menu menu, int instance) {
    menu.add(new MenuItem("A", 20, 10) {
        public void run() {
            answerMenu("A");
        }
    });
    menu.add(new MenuItem("B", 30, 20) {
        public void run() {
            answerMenu("B");
        }
    });
    menu.add(new MenuItem("C", 40, 30) {
        public void run() {
            answerMenu("C");
        }
    });
    menu.add(new MenuItem("D", 50, 40) {
        public void run() {
            answerMenu("D");
        }
    });
    super.makeMenu(menu, instance);
}

private void answerMenu(String answer) {
    DBMain.selectedAnswer = answer;

    UiApplication.getUiApplication().pushScreen(new AnswerScreen());
    UiApplication.getUiApplication().popScreen(getScreen());

}

protected boolean keyChar(char character, int status, int time) {
    if (character == 'A' || character == 'a')
        DBMain.selectedAnswer = "A";
    else if (character == 'B' || character == 'b')
        DBMain.selectedAnswer = "B";
    else if (character == 'C' || character == 'c')
        DBMain.selectedAnswer = "C";
    else if (character == 'D' || character == 'd')
        DBMain.selectedAnswer = "D";
    else
        return super.keyChar(character, status, time);

    UiApplication.getUiApplication().pushScreen(new AnswerScreen());
    UiApplication.getUiApplication().popScreen(getScreen());
    return true;
}



protected void paint(Graphics g) {
    g.drawBitmap(0, 0, UIinitialize.screenWidth, UIinitialize.screenHeight,
            backgroundBitmap, 0, 0);
    subpaint(g);
    TestScreen.this.invalidate();
}
}

Answer 1

我从您的大代码片段中看到您有几个使用 PersistentStore 的代码块类但被注释掉了。您走在正确的道路上 - 这是将数据保存到设备闪存的正确方法。如果您对此有更具体的问题，请完善您的答案以使其更具体。否则，请查看链接的 javadoc，以获取有关如何使用该类的详细说明，包括代码示例。