在 TableViewer 中添加、编辑、删除元素

Question

我创建了一个包含两列的 TableViewer，我想在按下一个名为“add”的按钮后向其中添加行。按下按钮后，我想创建一个空行，第一列单元格将提供输入文本的选项，第二列单元格将提供在系统目录中浏览以选择文件夹的选项。

单击“添加”按钮后，我设法添加了一个空行，但它返回以下错误：发生错误。有关详细信息，请参阅错误日志。断言失败：第 0 列没有标签提供者。 tableviewer 的目的是在第一列单元格中插入一个字符串变量，在第二列单元格中插入一个路径。使用用户插入的数据，我想创建一个名为 ProjectDirectory 的类的列表（该类有两个 String 属性）。

我还设法删除了我用鼠标选择的行，这很好。

我是使用 Jface 和 SWT 的新手，但我无法做到这一点。谁能帮帮我？

代码：

    Composite tableComposite = new Composite(pluginPathCreatedComposite, SWT.NONE);
    FormData tableCompositeData = new FormData();
    tableCompositeData.left = new FormAttachment(selectProjectPathLabel, 0, SWT.LEFT);
    tableCompositeData.top = new FormAttachment(selectProjectPathLabel, 40, SWT.TOP);
    tableCompositeData.right = new FormAttachment(selectProjectPathButton,-10,SWT.LEFT);
    tableCompositeData.bottom = new FormAttachment(createProjectConfigButton,-10,SWT.TOP);
    tableComposite.setLayoutData(tableCompositeData);

    //Create the tableviewer
    tableViewer = new TableViewer(tableComposite, SWT.SINGLE | SWT.FULL_SELECTION | SWT.H_SCROLL | SWT.V_SCROLL);
    Table table = tableViewer.getTable();
    tableViewer.getTable().setLinesVisible(true);
    tableViewer.getTable().setHeaderVisible(true);
    tableViewer.setColumnProperties(COLUMN_HEADINGS);

    //Create the tableViewer columns
    TableViewerColumn variable = new TableViewerColumn(tableViewer, SWT.NONE);
    variable.getColumn().setText(COLUMN_HEADINGS[0]);
    variable.getColumn().setResizable(false);

    TableViewerColumn path = new TableViewerColumn(tableViewer, SWT.NONE);
    path.getColumn().setText(COLUMN_HEADINGS[1]);
    path.getColumn().setResizable(false);

    TableColumnLayout tableLayout = new TableColumnLayout();
    tableComposite.setLayout(tableLayout);

    //Set the columns proportions
    tableLayout.setColumnData(path.getColumn(), new ColumnWeightData(50));
    tableLayout.setColumnData(variable.getColumn(), new ColumnWeightData(50));

    //Set the first row as TextCell (this doesn´t work)
    CellEditor[] editors = new CellEditor[2];
    editors[0] = new TextCellEditor(tableViewer.getTable());
    editors[1] = new TextCellEditor(tableViewer.getTable());
    tableViewer.setCellEditors(editors);

    //Add button
    Button addRow = new Button(pluginPathCreatedComposite, SWT.NONE);
    FormData addRowData = new FormData();
    addRowData.top = new FormAttachment(tableComposite,0,SWT.TOP);
    addRowData.left = new FormAttachment(selectProjectPathButton,0,SWT.LEFT);
    addRowData.right = new FormAttachment(selectProjectPathButton,0,SWT.RIGHT);
    addRow.setLayoutData(addRowData);
    addRow.setText("Add");

    addRow.addSelectionListener(new SelectionAdapter() {
        @Override
        public void widgetSelected(SelectionEvent e) {


            ProjectDirectory directory = new ProjectDirectory("A", "A");
            Table table = tableViewer.getTable();
            tableViewer.add(directory);
            table.setTopIndex(table.getItemCount());
            table.select(table.getItemCount() - 1);
        }
    });

    //Delete row
    Button deleteRow = new Button(pluginPathCreatedComposite, SWT.NONE);
    FormData deleteRowData = new FormData();
    deleteRowData.top = new FormAttachment(addRow,5,SWT.BOTTOM);
    deleteRowData.left = new FormAttachment(selectProjectPathButton,0,SWT.LEFT);
    deleteRowData.right = new FormAttachment(selectProjectPathButton,0,SWT.RIGHT);
    deleteRow.setLayoutData(deleteRowData);
    deleteRow.setText("Delete");

    deleteRow.addSelectionListener(new SelectionAdapter() {
        @Override
        public void widgetSelected(SelectionEvent e) {
            ISelection selection = tableViewer.getSelection();
            if (selection instanceof IStructuredSelection) {
                Iterator iterator = ((IStructuredSelection) selection).iterator();
                while (iterator.hasNext()) {
                    Object obj = iterator.next();
                    tableViewer.remove(obj);
                }
            }
        }
    });

图片：

UI

编辑：

我创建了一个内容提供程序来获取在代码中创建的列表的 ProjectDirectories（我将来会更改它）。之后，我为每一列创建了一个标签提供程序，它显示了我想要的数据。

事实是，我想在按下添加按钮后在表格中添加一个新行，并且我想让第一个单元格成为 TextCellEditor（第二个单元格将有一个事件来打开系统的目录路径为图像之一，但在此之前，我还想将其设为 TextCellEditor）。我已经定义了这两列就像 TextCell 编辑器一样，在按下添加按钮后，我设法添加了一个空行，但我无法在其中输入文本。我还创建了一个 setCellModifier 来更新 tableviewer。我做错了什么？

代码

    Composite tableComposite = new Composite(pluginPathCreatedComposite, SWT.NONE);
    FormData tableCompositeData = new FormData();
    tableCompositeData.left = new FormAttachment(selectProjectPathLabel, 0, SWT.LEFT);
    tableCompositeData.top = new FormAttachment(selectProjectPathLabel, 40, SWT.TOP);
    tableCompositeData.right = new FormAttachment(selectProjectPathButton,-10,SWT.LEFT);
    tableCompositeData.bottom = new FormAttachment(createProjectConfigButton,-10,SWT.TOP);
    tableComposite.setLayoutData(tableCompositeData);

    tableViewer = new TableViewer(tableComposite, SWT.SINGLE | SWT.FULL_SELECTION | SWT.H_SCROLL | SWT.V_SCROLL);
    table = tableViewer.getTable();
    table.setLinesVisible(true);
    table.setHeaderVisible(true);
    tableViewer.setColumnProperties(COLUMN_HEADINGS);

    //Content provider
    tableViewer.setContentProvider(new ProjectConfigTableContentProvider());

    /*I have tried to use this instead of setting the label providers in the column definitions*/
   //tableViewer.setLabelProvider(new ProjectConfigTableLabelProvider());

    //Label provider setted in each column
    TableViewerColumn variable = new TableViewerColumn(tableViewer, SWT.NONE);
    variable.getColumn().setText(COLUMN_HEADINGS[0]);
    variable.getColumn().setResizable(false);
    variable.setLabelProvider(new ColumnLabelProvider(){
        public String getText(Object element) {
            if(element instanceof ProjectDirectory && element != null)
                return ((ProjectDirectory)element).getName();
            return super.getText(element);
        }
    });

    TableViewerColumn path = new TableViewerColumn(tableViewer, SWT.NONE);
    path.getColumn().setText(COLUMN_HEADINGS[1]);
    path.getColumn().setResizable(false);
    path.setLabelProvider(new ColumnLabelProvider(){
        public String getText(Object element) {
            if(element instanceof ProjectDirectory && element != null)
                return ((ProjectDirectory)element).getPath();
            return super.getText(element);
        }
    });

    //List created in code (will change this in the future)
    List<ProjectDirectory> b = new ArrayList<ProjectDirectory>();
    b.add(new ProjectDirectory("AA", "FF"));
    b.add(new ProjectDirectory("BB", "CC"));

    Project pro = new Project("A", "B", 2, b);

    //Input setted
    tableViewer.setInput(pro);

    TableColumnLayout tableLayout = new TableColumnLayout();
    tableComposite.setLayout(tableLayout);

    tableLayout.setColumnData(path.getColumn(), new ColumnWeightData(50));
    tableLayout.setColumnData(variable.getColumn(), new ColumnWeightData(50));

    CellEditor[] editors = new CellEditor[2];
    editors[0] = new TextCellEditor(table);
    editors[1] = new TextCellEditor(table);
    tableViewer.setCellEditors(editors);
    tableViewer.setCellModifier(new ProjectConfigTableCellModifier(COLUMN_HEADINGS,tableViewer));

    //addrow button
    Button addRow = new Button(pluginPathCreatedComposite, SWT.NONE);
    FormData addRowData = new FormData();
    addRowData.top = new FormAttachment(tableComposite,0,SWT.TOP);
    addRowData.left = new FormAttachment(selectProjectPathButton,0,SWT.LEFT);
    addRowData.right = new FormAttachment(selectProjectPathButton,0,SWT.RIGHT);
    addRow.setLayoutData(addRowData);
    addRow.setText("Add");

    addRow.addSelectionListener(new SelectionAdapter() {
        @Override
        public void widgetSelected(SelectionEvent e) {
            ProjectDirectory directory = new ProjectDirectory("", "");
            tableViewer.add(directory);
            table.setTopIndex(table.getItemCount());
            table.select(table.getItemCount() - 1);
            tableViewer.editElement(directory, 0);
        }
    });

我还创建了一个 labelProvider 类，以避免像我所做的那样在每列中设置标签提供程序，但它不起作用。代码是这样的：

@Override
    public String getColumnText(Object element, int columnIndex) {
    // TODO Auto-generated method stub
    ProjectDirectory projectDirectory = (ProjectDirectory) element;

    switch (columnIndex) {
    case 0:
        return projectDirectory.getName();
    case 1:
        return projectDirectory.getPath();
    }
    return null;
}

对类的调用是这样的：

tableViewer.setLabelProvider(new ProjectConfigTableLabelProvider());

为什么只将标签提供程序设置到列而这种方式不起作用？

Answer 1

好的，我找到了解决问题的方法。

首先，我创建了一个组合，它将在更大的组合中包含表格。

     private Composite createPluginPathCreatedComposite(){

        .................................

        //Label of bigger composite
        Text selectProjectPathText = new Text(pluginPathCreatedComposite, SWT.BORDER);
        selectProjectPathText.setEnabled(false);
        FormData selectProjectPathTextData = new FormData();
        selectProjectPathTextData.top = new FormAttachment(selectProjectPathLabel, 0, SWT.CENTER);
        selectProjectPathTextData.left = new FormAttachment(selectProjectPathLabel, 5,SWT.RIGHT);
        selectProjectPathTextData.right = new FormAttachment(100,-55);
        selectProjectPathText.setLayoutData(selectProjectPathTextData); 

        //Button to select a system directory
        Button selectProjectPathButton = new Button(pluginPathCreatedComposite, SWT.NONE);
        selectProjectPathButton.setText("Browse");
        FormData selectProjectPathButtonData = new FormData();
        selectProjectPathButtonData.top = new FormAttachment(selectProjectPathText, 0, SWT.TOP);
        selectProjectPathButtonData.left = new FormAttachment(selectProjectPathText, 5, SWT.RIGHT);
        selectProjectPathButtonData.right = new FormAttachment(100,-5);
        selectProjectPathButton.setLayoutData(selectProjectPathButtonData); 
        selectProjectPathButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                DirectoryDialog dialog = new DirectoryDialog(Display.getCurrent().getActiveShell());
                dialog.setFilterPath(""); // Windows specific
                selectProjectPathText.setText(dialog.open());
            }
        });

        //Create a composite for the table inside a bigger composite pluginPathCreatedComposite
        Composite tableComposite = new Composite(pluginPathCreatedComposite, SWT.NONE);
        FormData tableCompositeData = new FormData();
        tableCompositeData.left = new FormAttachment(selectProjectPathLabel, 0, SWT.LEFT);
        tableCompositeData.top = new FormAttachment(selectProjectPathLabel, 40, SWT.TOP);
        tableCompositeData.right = new FormAttachment(selectProjectPathButton,-10,SWT.LEFT);
        tableCompositeData.bottom = new FormAttachment(createProjectConfigButton,-10,SWT.TOP);
        tableComposite.setLayoutData(tableCompositeData);

        //Function to create the table. 
        createTable(tableComposite,selectProjectPathText);

        //add row to the tableviewer
        addRow.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                ProjectDirectory directory = new ProjectDirectory("Insert variable", "Click to add path");
                projectCompositeViewer.add(directory);
            }
        });

        //deleterow from the tableviewer
        Button deleteRow = new Button(pluginPathCreatedComposite, SWT.NONE);
        FormData deleteRowData = new FormData();
        deleteRowData.top = new FormAttachment(addRow,5,SWT.BOTTOM);
        deleteRowData.left = new FormAttachment(selectProjectPathButton,0,SWT.LEFT);
        deleteRowData.right = new FormAttachment(selectProjectPathButton,0,SWT.RIGHT);
        deleteRow.setLayoutData(deleteRowData);
        deleteRow.setText("Delete");

        deleteRow.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {
                ISelection selection = projectCompositeViewer.getSelection();
                if (selection instanceof IStructuredSelection) {
                    Iterator iterator = ((IStructuredSelection) selection).iterator();
                    while (iterator.hasNext()) {
                        Object obj = iterator.next();
                        projectCompositeViewer.remove(obj);
                    }
                }
            }
        });
        }

创建表函数，我已将表 Composite 和项目文件夹的路径作为参数传递：

    private void createTable(Composite tableComposite, Text selectProjectPathText){
        //Create the tableViewer and it´s columns
        projectCompositeViewer = new ProjectConfigViewer(tableComposite, selectProjectPathText,SWT.SINGLE | SWT.FULL_SELECTION | SWT.H_SCROLL | SWT.V_SCROLL);

        //Create an input to display
        List<ProjectDirectory> b = new ArrayList<ProjectDirectory>();
        b.add(new ProjectDirectory("AA", "FF"));
        b.add(new ProjectDirectory("BB", "CC"));

        Project pro = new Project("A", "B", 2, b);
        projectCompositeViewer.setInput(pro);
    }

ProjectConfigViewer 代码：

public class ProjectConfigViewer extends TableViewer{

    public ProjectConfigViewer(Composite parent, Text selectProjectPathText,int style) 
    {
        super(parent, style);
        Table table = getTable();
        createColumns(parent, selectProjectPathText);
        table.setHeaderVisible(true);
        table.setLinesVisible(true);

        //Specify Content provider
        setContentProvider(new ProjectConfigTableContentProvider());
    }

    //Create the columns, column´s label providers and editingsuport to specify how will each column cell be: text column, dialog column...
    private void createColumns(Composite parent,Text selectProjectPathText)
    {   
        String[] COLUMN_HEADINGS = {"Variable", "Path"};

        TableColumnLayout tableLayout = new TableColumnLayout();
        parent.setLayout(tableLayout);

        //Specify first column labelprovider and create it 
        TableViewerColumn variable = createTableViewerColumn(COLUMN_HEADINGS[0], 0);
        variable.getColumn().setResizable(false);
        variable.setLabelProvider(new ColumnLabelProvider(){
            public String getText(Object element) {
                if(element instanceof ProjectDirectory && element != null)
                    return ((ProjectDirectory)element).getName();
                return super.getText(element);
            }
        });

         //Specify second column labelprovider and create it
        TableViewerColumn path = createTableViewerColumn(COLUMN_HEADINGS[1], 1);
        path.getColumn().setResizable(false);
        path.setLabelProvider(new ColumnLabelProvider(){
            public String getText(Object element) {
                if(element instanceof ProjectDirectory && element != null)
                    return ((ProjectDirectory)element).getPath();
                return super.getText(element);
            }
        });

        //Spedify the dimensions of each column
        tableLayout.setColumnData(path.getColumn(), new ColumnWeightData(50));
        tableLayout.setColumnData(variable.getColumn(), new ColumnWeightData(50));

        //Specify setEditingSupport for each cell. First cell will be text, second will be a Dialog.
        variable.setEditingSupport(new ProjectConfigVariableEditingSupport(this));
        path.setEditingSupport(new ProjectConfigPathEditingSupport(this, selectProjectPathText));
    }

    //Create tableviewercolumns
    private TableViewerColumn createTableViewerColumn(String header, int idx) 
    {
        TableViewerColumn column = new TableViewerColumn(this, SWT.LEFT, idx);
        column.getColumn().setText(header);
        column.getColumn().setResizable(true);
        column.getColumn().setMoveable(true);

        return column;
    }
}

内容提供者：

public class ProjectConfigTableContentProvider implements IStructuredContentProvider {
    private List<ProjectDirectory> projectEntitiesList;

    @Override
    public Object[] getElements(Object arg0) {
        // TODO Auto-generated method stub
        if (arg0 instanceof Project){
            Project project = (Project) arg0; 
            if (project != null && project.getProjectDirectoriesList() != null){
                initializeTableProjectConfig(project);
                return projectEntitiesList.toArray();
            }
        }
        projectEntitiesList = new ArrayList<ProjectDirectory>();
        return projectEntitiesList.toArray();
    }

    private void initializeTableProjectConfig(Project project){
        try {
            List<ProjectDirectory> listProjectDirectory = new ArrayList<ProjectDirectory>();
            for (ProjectDirectory projectDirectory : project.getProjectDirectoriesList()) {
                if (projectDirectory != null) 
                    listProjectDirectory.add(projectDirectory);
            }
            this.projectEntitiesList = listProjectDirectory;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

第一列的编辑支持：

public class ProjectConfigVariableEditingSupport extends EditingSupport {
    private TextCellEditor cellEditor;

    public ProjectConfigVariableEditingSupport(ColumnViewer viewer) {
        super(viewer);
        cellEditor = new TextCellEditor(((TableViewer)viewer).getTable());
    }
    protected CellEditor getCellEditor(Object element) {
        return cellEditor;
    }
    protected boolean canEdit(Object element) {
        return true;
    }
    protected Object getValue(Object element) {
        return ((ProjectDirectory) element).getName();
    }
    @Override
    protected void setValue(Object element, Object value) {
        ((ProjectDirectory) element).setName(String.valueOf(value));
        getViewer().update(element, null);
    }
}

第二列的编辑支持：

public class ProjectConfigPathEditingSupport extends EditingSupport{
    private DialogCellEditor  cellEditor;

    //Pass selecProjectPathText of the bigger composite to brose from that directory
    public ProjectConfigPathEditingSupport(ColumnViewer viewer, Text selectProjectPathText) {
        super(viewer);
        cellEditor = new DialogCellEditor(((TableViewer)viewer).getTable()) {
            @Override
            protected Object openDialogBox(Control cellEditorWindow) {
                // TODO Auto-generated method stub
                DirectoryDialog dialog = new DirectoryDialog(cellEditorWindow.getShell());
                dialog.setText("Browse");
                dialog.setFilterPath(selectProjectPathText.getText()); // Windows specific
                return  dialog.open();
            }
        };
    }
    protected CellEditor getCellEditor(Object element) {
        return cellEditor;
    }
    protected boolean canEdit(Object element) {
        return true;
    }
    protected Object getValue(Object element) {
        return ((ProjectDirectory) element).getPath();
    }
    protected void setValue(Object element, Object value) 
    {
        ((ProjectDirectory) element).setPath(String.valueOf(value));
        getViewer().update(element, null);
    }
}

模型类：

public class Project {
    private String name;
    private String path;
    private Integer quantity;
    private List<ProjectDirectory> projectDirectoryList;

    //Constructor
    public Project(String name, String path, Integer quantity, List<ProjectDirectory> projectDirectoriesList) {
        super();
        this.name = name;
        this.path = path;
        this.quantity = quantity;
        this.projectDirectoryList = projectDirectoriesList;
    }
    //GETTERS AND SETTERS
}

public class ProjectDirectory {
    private String name;
    private String path;

    //Constructor
    public ProjectDirectory(String name, String path) {
        super();
        this.path = path;
        this.name = name;
    }

    //Getters & setters

照片： Explanation of use

Answer 2

此问题的最简单原因之一是在创建列之前添加了标签提供程序。始终确保标签提供程序是在之后添加的！