我对这种解决方案不满意，但是它可以工作。
绝对是
XXX
解决方案
在评论中使用
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标记虚假但有效的内容。使用FIXME标记虚假和损坏的内容。 -java.sun.com
无需再费周折
import org.eclipse.swt.*;import org.eclipse.swt.layout.*;import org.eclipse.swt.widgets.*;import org.eclipse.swt.events.ExpandEvent;import org.eclipse.swt.events.ExpandListener;public class ExpandBarExample { public static void main(String[] args) { Shell shell = new Shell(SWT.DIALOG_TRIM | SWT.MIN | SWT.APPLICATION_MODAL); shell.setLayout(new FormLayout()); shell.setText("Expand Bar"); final ExpandBar bar = new ExpandBar(shell, SWT.NONE); FormData fd = new FormData(); fd.top = new FormAttachment(0); fd.left = new FormAttachment(0); fd.right = new FormAttachment(100); fd.bottom = new FormAttachment(100); bar.setLayoutData(fd); bar.addExpandListener(new ExpandListener() { private void resize(final ExpandEvent event, final boolean expand){ final Display display = Display.getCurrent(); new Thread(new Runnable() { public void run() { final int[] orgSize = new int[1]; final int[] currentSize = new int[1]; final Object lock = new Object(); if (display.isDisposed() || bar.isDisposed()){ return; } display.syncExec(new Runnable() { public void run() { if (bar.isDisposed() || bar.getShell().isDisposed()){ return; } synchronized(lock){ bar.getShell().pack(true); orgSize[0] = bar.getShell().getSize().y; currentSize[0] = orgSize[0]; } } }); while (currentSize[0] == orgSize[0]){ if (display.isDisposed() || bar.isDisposed()){ return; } display.syncExec(new Runnable() { public void run() { synchronized(lock){ if (bar.isDisposed() || bar.getShell().isDisposed()){return; } currentSize[0] = bar.getShell().getSize().y; if (currentSize[0] != orgSize[0]){return; } else{bar.getShell().layout(true);bar.getShell().pack(true); } } } }); } } }).start(); } public void itemCollapsed(ExpandEvent event) { resize(event, false); } public void itemExpanded(ExpandEvent event) { resize(event, true); } }); Composite composite = new Composite(bar, SWT.NONE); fd = new FormData(); fd.left = new FormAttachment(0); fd.right = new FormAttachment(100); composite.setLayoutData(fd); FormLayout layout = new FormLayout(); layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8; composite.setLayout(layout); Label label = new Label(composite, SWT.NONE); label.setText("This is Bar 1"); ExpandItem item1 = new ExpandItem(bar, SWT.NONE, 0); item1.setText("Bar 1"); item1.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y); item1.setControl(composite); item1.setExpanded(true); composite = new Composite(bar, SWT.NONE); fd = new FormData(); fd.left = new FormAttachment(0); fd.right = new FormAttachment(100); composite.setLayoutData(fd); layout = new FormLayout(); layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8; composite.setLayout(layout); label = new Label(composite, SWT.NONE); label.setText("This is Bar2"); ExpandItem item2 = new ExpandItem(bar, SWT.NONE, 1); item2.setText("Bar 2"); item2.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y); item2.setControl(composite); item2.setExpanded(true); composite = new Composite(bar, SWT.NONE); fd = new FormData(); fd.left = new FormAttachment(0); fd.right = new FormAttachment(100); composite.setLayoutData(fd); layout = new FormLayout(); layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8; composite.setLayout(layout); label = new Label(composite, SWT.NONE); label.setText("This is Bar3"); ExpandItem item3 = new ExpandItem(bar, SWT.NONE, 2); item3.setText("Bar 3"); item3.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y); item3.setControl(composite); item3.setExpanded(true); bar.setSpacing(6); shell.pack(); shell.open(); Display display = shell.getDisplay(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) { display.sleep(); } } display.dispose(); }}如果有人想知道它在做什么并且不想看代码。
基本上， ExpandListener会 查看外壳的原始高度，并发出syncExec来 打包（）
外壳，直到外壳实际更改大小为止。一个非常繁忙的等待方法。
