嘗試添加進度時進度條變爲空

此欄用於向用戶顯示URL到IP轉換的進度，基本上你可以輸入網址的列表並將它們轉換成IP地址，這一切都很完美然而，長列表中可能需要幾秒鐘，這就是我添加進度條的原因。嘗試添加進度時進度條變爲空

我之前使用過一個進度條來給用戶一個完成下載的百分比，但在這種情況下，它似乎並不像我給它的值。如果我打印的價值它正確打印例如，

雖然打印

System.out.println(Progress.percentage);

然而，當我嘗試設置一個新的字符串或崩潰進度條的新值。

try { 
    Progress.main(null); 
    Progress.totalToDo = IPArray.size(); 
    for (String URL : IPArray) { 
     URL url = new URL(URL); 
     InetAddress address = InetAddress.getByName(url.getHost()); 
     String temp = address.toString(); 
     String IP = temp.substring(temp.indexOf("/") + 1, temp.length()); 
     URLArray.add(IP); 
     Progress.percentage = (URLArray.size() * 100)/Progress.totalToDo; 
     Progress.ipProgress.setString(Progress.percentage + "%"); 
     Progress.ipProgress.setValue(Progress.percentage); 
     result += IP + System.getProperty("line.separator"); 
    } 
    IPFrame.textAreaIP.setText(result); 
    GEOLookup.check(IPFrame.textAreaIP.getText()); 
}

如果您需要更多的信息不要害怕問，請感謝任何幫助。

編輯：對不起忘了將它張貼打印錯誤，我知道錯誤是由

Progress.ipProgress.setString(Progress.percentage + "%"); 
Progress.ipProgress.setValue(Progress.percentage);

因爲一旦刪除的應用程序進行精細造成的。打印錯誤如下。

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException 
    at com.elvazar.ipgrabber.IPGrabber.convert(IPGrabber.java:86) 
    at com.elvazar.ipgrabber.IPFrame.jButton4ActionPerformed(IPFrame.java:335) 
    at com.elvazar.ipgrabber.IPFrame.access$700(IPFrame.java:23) 
    at com.elvazar.ipgrabber.IPFrame$8.actionPerformed(IPFrame.java:125) 
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018) 
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341) 
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) 
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259) 
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252) 
    at java.awt.Component.processMouseEvent(Component.java:6505) 
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321) 
    at java.awt.Component.processEvent(Component.java:6270) 
    at java.awt.Container.processEvent(Container.java:2229) 
    at java.awt.Component.dispatchEventImpl(Component.java:4861) 
    at java.awt.Container.dispatchEventImpl(Container.java:2287) 
    at java.awt.Component.dispatchEvent(Component.java:4687) 
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832) 
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492) 
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422) 
    at java.awt.Container.dispatchEventImpl(Container.java:2273) 
    at java.awt.Window.dispatchEventImpl(Window.java:2719) 
    at java.awt.Component.dispatchEvent(Component.java:4687) 
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735) 
    at java.awt.EventQueue.access$200(EventQueue.java:103) 
    at java.awt.EventQueue$3.run(EventQueue.java:694) 
    at java.awt.EventQueue$3.run(EventQueue.java:692) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87) 
    at java.awt.EventQueue$4.run(EventQueue.java:708) 
    at java.awt.EventQueue$4.run(EventQueue.java:706) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76) 
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:705) 
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242) 
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161) 
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146) 
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138) 
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

來源

2013-07-29 TehBawz

您是否在您的progressBar對象上使用「.setStringPainted（true）」將「stringPainted」設置爲true？否則，你的字符串將不會出現在欄上。你也應該看看「BoundedRangeModel」，以便更新值。換句話說，只要看看Javadoc。（誰說RTFM？））http://docs.oracle.com/javase/7/docs/api/javax/swing/JProgressBar.html#setValue(int） –

是的，我做到了。但即使我沒有，那麼它不會打印一個錯誤只是不會更新？這也提醒了我，我應該發佈我的錯誤。 – TehBawz

什麼是Progress對象btw的類？ NPE可能來自ipProgress上的「.set」方法，你確定ipProgress！= null？ –

想象一下，不得不用事件隊列調用它。感謝所有的反饋。

來源

2013-07-29 11:58:19 TehBawz

嘗試添加進度時進度條變爲空

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