Question

我为学生制作方法，向每个学生展示我的GUI，我希望有选项将我的GUi保存到xml文件中。我的问题是我有错误空指针异常

我解决了写作学生的问题

我制作私人综合mSTUDENTChild;

我每写studentChild = mSTUDENTChild;并写入保存部分我做

 Control[] currentSTUDENTOnGui = mSTUDENTChild.getChildren();

我的问题是写出我有的主题

public void displaySTUDENTTab(TabFolder tabFolderAdministration, CurrentData currentData){

        TabItem tbtmSTUDENT = new TabItem(tabFolderAdministration, SWT.NONE);
        tbtmSTUDENT.setText("STUDENT");

        ScrolledComposite scrolledComposite_7 = new ScrolledComposite(tabFolderAdministration, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
        tbtmSTUDENT.setControl(scrolledComposite_7);
        scrolledComposite_7.setExpandHorizontal(true);
        scrolledComposite_7.setExpandVertical(true);

        List<STUDENT> allStudentNodes = currentData.getstudentNodes();


        final Composite studentChild = new Composite(scrolledComposite_7, SWT.NONE);
        studentChild.setLayout(new GridLayout());

        for(STUDENT studentNode: allStudentNodes){

            new studentNode(this, studentChild, SWT.NONE, studentNode);

            Composite subjectChild = new Composite(studentChild, SWT.NONE);
            GridLayout bladeGrid = new GridLayout(9, true);
            subjectChild.setLayout(bladeGrid);

            for(Blade bladeNode: studentNode.getBlades()){
                new BladeID(subjectChild, SWT.NONE, bladeNode);
            }
            msubjectChild = subjectChild;
        }
        mstudentChild = studentChild;

        scrolledComposite_7.setContent(studentChild);
        scrolledComposite_7.setMinSize(studentChild.computeSize(SWT.DEFAULT, SWT.DEFAULT));
        scrolledComposite_7.pack();
    }

我制作了saveas方法，现在正在使用这是我保存的代码，我有课程SUBJECT，SUBJECTID和AddSubject

 Control[] currentSTUDENTOnGui = studentChild.getChildren();
int noOfBCs = -1;
currentData.getStudentNodes().clear();
 for (int i = 0; i < currentSTUDENTOnGui.length; i++) {
    boolean isBCNode = false;
    SubjectNode subjectOnGuii = null;
    STUDENTNode nodeOnGuiSTUDENT = null;
    try {
        nodeOnGuiSTUDENT = (STUDENTNode) currentSTUDENTOnGui[i];
        isBCNode = true;
        noOfBCs++;
    } catch (ClassCastException e) {
        subjectOnGuii = (SubjectNode) currentSTUDENTOnGui[i];
    }
    if (isBCNode) {
        STUDENT nodeWithDataSTUDENT = new STUDENT(nodeOnGuiSTUDENT.getText(), nodeOnGuiSTUDENT.getText_1(), nodeOnGuiSTUDENT.getText_2(), nodeOnGuiSTUDENT.getText_3(),
        nodeOnGuiSTUDENT.getText_4(), nodeOnGuiSTUDENT.getText_5(), nodeOnGuiSTUDENT.getText_6(), nodeOnGuiSTUDENT.getText_7(), nodeOnGuiSTUDENT.getText_8(), nodeOnGuiSTUDENT.getText_9(), nodeOnGuiSTUDENT.getText_10(),
        nodeOnGuiSTUDENT.getText_11(), nodeOnGuiSTUDENT.getText_12(), nodeOnGuiSTUDENT.getText_13(), nodeOnGuiSTUDENT.getText_14(), nodeOnGuiSTUDENT.getText_15(), nodeOnGuiSTUDENT.getText_16());
        currentData.getStudentNodes().add(nodeWithDataSTUDENT);
        continue;
    }
    STUDENT lastNodeWithData = currentData.getStudentNodes().get(noOfBCs);
    SUBJECT subjectToAdd = new SUBJECT(subjectOnGuii.getId(), subjectOnGuii.getSessionType(), subjectOnGuii.getUser(), subjectOnGuii.getSupwd(), subjectOnGuii.getPort());
    lastNodeWithData.getSubject().add(subjectToAdd);
    currentData.getStudentNodes().set(noOfBCs, lastNodeWithData);
}

在java中保存来自gui的数据

0 个答案: