SWT异常: org.eclipse.swt.SWTException: Invalid threa

在创建SWT界面的线程之外的线程中尝试去修改界面元素.将抛出以下异常

Exception in thread "Thread-0" org.eclipse.swt.SWTException: Invalid thread access

at org.eclipse.swt.SWT.error(SWT.java:2942)

at org.eclipse.swt.SWT.error(SWT.java:2865)

at org.eclipse.swt.SWT.error(SWT.java:2836)

上述Thread-0是另外开启的一个线程.

【解析】:

在SWT程序中,

SWT会自动创建一个用户界面线程

非用户界面线程不能直接操作用户界面线程

要想在另外一个线程中尝试修改用户界面,应采用一下方法:

if (!this.display.isDisposed()) {

       Runnable runnable = new Runnable() {

            public void run() {

                  // 你改界面的代码

             }

             };

       display.syncExec(runnable); // 关键在这一句上

}

swt-doc中的说明:

public void syncExec(java.lang.Runnable runnable)

Causes the run() method of the runnable to be invoked by the user-interface thread at the next reasonable opportunity. The thread which calls this method is suspended until the runnable completes.

Parameters:

runnable - code to run on the user-interface thread.

此外,与之对应的另一个方法:

public void asyncExec(java.lang.Runnable runnable)

Causes the run() method of the runnable to be invoked by the user-interface thread at the next reasonable opportunity. The caller of this method continues to run in parallel, and is not notified when the runnable has completed.

Parameters:

runnable - code to run on the user-interface thread.