It’s not possible to force the Table to always show scroll bars, the OS decides when to show them.

备择方案

是的,我提出了一个非常类似于我对这个问题的答案的解决方案：

我们的想法是使用ScrolledComposite(作为已建议的另一个答案)来处理滚动.表本身不会滚动.但是,这不会有任何区别,因为用户无法区分.

ScrolledComposite有一个名为setAlwaysShowScrollBars(boolean)的方法,您可以使用该方法强制它始终显示滚动条,即使它们不是必需的.

这是一些示例代码,它将说明我刚才谈到的内容：

public static void main(String[] args)

{

final Display display = new Display();

final Shell shell = new Shell(display);

shell.setLayout(new GridLayout());

final ScrolledComposite composite = new ScrolledComposite(shell, SWT.V_SCROLL);

composite.setLayout(new GridLayout());

composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

final Table table = new Table(composite, SWT.NO_SCROLL | SWT.FULL_SELECTION);

table.setHeaderVisible(true);

composite.setContent(table);

composite.setExpandHorizontal(true);

composite.setExpandVertical(true);

composite.setAlwaysShowScrollBars(true);

composite.setMinSize(table.computeSize(SWT.DEFAULT, SWT.DEFAULT));

Button fillTable = new Button(shell, SWT.PUSH);

fillTable.setText("Fill table");

fillTable.setLayoutData(new GridData(SWT.FILL, SWT.END, true, false));

fillTable.addListener(SWT.Selection, new Listener()

{

@Override

public void handleEvent(Event arg0)

{

if (table.getColumnCount() < 1)

{

for (int col = 0; col < 4; col++)

{

TableColumn column = new TableColumn(table, SWT.NONE);

column.setText("Column " + col);

}

}

for (int row = 0; row < 20; row++)

{

TableItem item = new TableItem(table, SWT.NONE);

for (int col = 0; col < table.getColumnCount(); col++)

{

item.setText(col, "Item " + row + " " + col);

}

}

for (int col = 0; col < table.getColumnCount(); col++)

{

table.getColumn(col).pack();

}

composite.setMinSize(table.computeSize(SWT.DEFAULT, SWT.DEFAULT));

}

});

Button clearTable = new Button(shell, SWT.PUSH);

clearTable.setText("Clear table");

clearTable.setLayoutData(new GridData(SWT.FILL, SWT.END, true, false));

clearTable.addListener(SWT.Selection, new Listener()

{

@Override

public void handleEvent(Event arg0)

{

table.removeAll();

composite.setMinSize(table.computeSize(SWT.DEFAULT, SWT.DEFAULT));

}

});

shell.pack();

shell.setSize(400, 300);

shell.open();

while (!shell.isDisposed())

{

if (!display.readAndDispatch())

display.sleep();

}

display.dispose();

}

看起来像这样：

如您所见,滚动条始终可见.

UPDATE

正如评论中所指出的,当您向下滚动时,此方法不会保持表标题可见.如果您可以发布一个说明问题的小工作代码示例,我们可能会提出一个替代方案(与强制滚动条无关).

UPDATE2

下面是一些应该做你想做的代码,诀窍就是在TableViewer的父级上触发resize事件,显示的水平滚动条不是必需的,并且在你调整窗口大小后它会消失：

public static void main(String[] args)

{

final Display display = new Display();

final Shell shell = new Shell(display);

shell.setText("StackOverflow");

shell.setLayout(new GridLayout());

createMasterPart(shell);

shell.pack();

shell.setSize(400, 300);

shell.open();

shell.layout(true, true);

while (!shell.isDisposed())

{

if (!display.readAndDispatch())

display.sleep();

}

display.dispose();

}

private static void createMasterPart(Composite parentComposite)

{

Composite composite = new Composite(parentComposite, SWT.NONE);

composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

composite.setLayout(new GridLayout(1, false));

Composite tableComposite = new Composite(composite, SWT.NONE);

TableColumnLayout tableColumnLayout = new TableColumnLayout();

tableComposite.setLayout(tableColumnLayout);

tableComposite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

TableViewer tableViewer = new TableViewer(tableComposite, SWT.BORDER | SWT.FULL_SELECTION);

tableViewer.setContentProvider(ArrayContentProvider.getInstance());

Table table = tableViewer.getTable();

table.setHeaderVisible(true);

table.setLinesVisible(true);

TableViewerColumn firstTableViewerColumn = new TableViewerColumn(tableViewer, SWT.NONE);

TableColumn firstTableColumn = firstTableViewerColumn.getColumn();

firstTableColumn.setText("Sample");

firstTableViewerColumn.setLabelProvider(new ColumnLabelProvider()

{

@Override

public String getText(Object element)

{

Dummy p = (Dummy) element;

return p.first;

}

});

TableViewerColumn secondTableViewerColumn = new TableViewerColumn(tableViewer, SWT.NONE);

TableColumn secondTableColumn = secondTableViewerColumn.getColumn();

secondTableColumn.setText("Speaker");

secondTableViewerColumn.setLabelProvider(new ColumnLabelProvider()

{

@Override

public String getText(Object element)

{

Dummy p = (Dummy) element;

return p.second;

}

});

TableViewerColumn thirdTableViewerColumn = new TableViewerColumn(tableViewer, SWT.NONE);

TableColumn thirdTableColumn = thirdTableViewerColumn.getColumn();

thirdTableColumn.setText("Remark");

thirdTableViewerColumn.setLabelProvider(new ColumnLabelProvider()

{

@Override

public String getText(Object element)

{

Dummy p = (Dummy) element;

return p.third;

}

});

List elements = new ArrayList<>();

for(int i = 0; i < 20; i++)

{

elements.add(new Dummy("firstfirstfirst " + i, "secondsecondsecond " + i, "thirdthirdthirdthirdthirdthird " + i));

}

tableViewer.setInput(elements);

tableColumnLayout.setColumnData(firstTableColumn, new ColumnWeightData(1, true));

tableColumnLayout.setColumnData(secondTableColumn, new ColumnWeightData(1, true));

tableColumnLayout.setColumnData(thirdTableColumn, new ColumnWeightData(2, true));

}

private static class Dummy

{

public String first;

public String second;

public String third;

public Dummy(String first, String second, String third)

{

this.first = first;

this.second = second;

this.third = third;

}

}