能不能给我一个JSlider控制Timer的Delay的例子，谢谢

goosebeery 2003-10-15 10:43:35

我想用一个JSlider控制Timer的Delay,我是这样写的
slider.addChangeListener(
new ChangeListener() {
public void stateChanged( ChangeEvent changeEvent )
{
timer.setDelay(slider.getValue());
}
}
);
可是每次改变slider的值时出现了这样的异常
Exception occurred during event dispatching:
java.lang.NullPointerException
at ovt.gui.CurrentMjdToolbarComponents$8.stateChanged(CurrentMjdToolbarC
omponents.java:366)
at javax.swing.JSlider.fireStateChanged(Unknown Source)
at javax.swing.JSlider$ModelListener.stateChanged(Unknown Source)
at javax.swing.DefaultBoundedRangeModel.fireStateChanged(Unknown Source)

at javax.swing.DefaultBoundedRangeModel.setRangeProperties(Unknown Sourc
e)
at javax.swing.DefaultBoundedRangeModel.setValue(Unknown Source)
at javax.swing.JSlider.setValue(Unknown Source)
at javax.swing.plaf.basic.BasicSliderUI$TrackListener.mouseDragged(Unkno
wn Source)
at java.awt.AWTEventMulticaster.mouseDragged(Unknown Source)
at java.awt.Component.processMouseMotionEvent(Unknown Source)
at javax.swing.JComponent.processMouseMotionEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
why?请各位高手帮忙，谢谢！

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