你必須使用線程.設計一個實現Runnable接口的類,它將更新這樣的值.

class ProgressBarUpdator implements java.lang.Runnable {

/**

* Progress bar that shows the current status

*/

private javax.swing.JProgressBar jpb = null;

/**

* Progress bar value

*/

private java.lang.Integer value = null;

/**

* Constructor

* @param jpb The progress bar this has to update

*/

public ProgressBarUpdator(javax.swing.JProgressBar jpb) {

this.jpb = jpb;

jpb.setMaximum(100);

}

/**

* Sets the value to the progress bar

* @param value Value to set

*/

public void setValue(java.lang.Integer value) {

this.value = value;

}

/**

* Action of the thread will be executed here. The value of the progress bar will be set here.

*/

public void run() {

do {

if (value != null) {

jpb.setValue((int)java.lang.Math.round(java.lang.Math.floor(value.intValue() * 100 / maximum)));

}

try {

java.lang.Thread.sleep(100L);

} catch (java.lang.InterruptedException ex) {

ex.printStackTrace();

}

} while (value == null || value.intValue() < jpb.getMaximum());

}

}

并且在你的frame類中使用progressBar和這樣的新類

ProgressBarUpdator ju = new ProgressBarUpdator(progressBar);

new java.lang.Thread(ju).start();

每當您想要更改值時,只需使用該語句即可

ju.setValue([Value to set]);