JScrollPane滚动刷新

Question

因为我的JScrollPane里有很多的JButton在拉滚动条时，有很明显的刷新跟不上，就是被拉出来的新画面会出现白的部分。
怎么能解决呀！！

Answer 1

把代碼貼出來看看～    如果沒有錯誤  swing不會出現這樣的狀況

Answer 2

主页面代码this.setSize(width, height);
getContentPane().setLayout(null);
this.setBackground(Color.BLACK);
this.setLocale(new java.util.Locale("sq"));
getContentPane().setForeground(new java.awt.Color(0,128,255));
this.setVisible(false);
{
devicePanel = new JPanel();
getContentPane().add(devicePanel);
devicePanel.setBackground(Color.white);
devicePanel.setLayout(null);
devicePanel.setName("devicePanel");
devicePanel.setBounds(0, 0, deviceWidth, deviceHeight);
{
jLabel1 = new JLabel();
devicePanel.add(jLabel1);

jLabel1.setText(devicetitleString);
jLabel1.setBounds(7, 7, deviceWidth-10, deviceHeight-10);
jLabel1.setFont(new java.awt.Font("MS Gothic",0,14));
}
}
{
headerPane = new GanttHeader();//JScrollPane
headerPane.setBackground(Color.white);
headerPane.setBounds(deviceWidth, 0, width-deviceWidth-17, height);
}
{
itemPane = new GanttItem();//JScrollPane

itemPane.setBounds(0, deviceHeight, width, height-deviceHeight-17);
}

{
ganttChart = new GanttChart();//JScrollPane

getContentPane().add(ganttChart);
getContentPane().add(itemPane);
getContentPane().add(headerPane);
ganttChart.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS );
ganttChart.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
ganttChart.setBounds(deviceWidth-1,deviceHeight,width-deviceWidth,height-deviceHeight);
JScrollBar   bar   =   ganttChart.getHorizontalScrollBar();  
JScrollBar   bar1   =   ganttChart.getVerticalScrollBar();


bar.addAdjustmentListener(new   AdjustmentListener()   
              {   
                  public   void   adjustmentValueChanged(AdjustmentEvent   e)   
                  {   JScrollBar   bar3   =   headerPane.getHorizontalScrollBar(); 
                    int a=e.getValue();
                    bar3.setValue(a);
                    bar3.addAdjustmentListener(new   AdjustmentListener(){
                     public   void   adjustmentValueChanged(AdjustmentEvent   e)   {
                    headerPane.repaint();}
                    });
                    repaint();
                  }   
              });
bar1.addAdjustmentListener(new   AdjustmentListener()   
              {   
                  public   void   adjustmentValueChanged(AdjustmentEvent   e)   
                  {   
                 JScrollBar   bar2   =   itemPane.getVerticalScrollBar(); 
                 int a=e.getValue();
                 bar2.setValue(a);
                 bar2.addAdjustmentListener(new   AdjustmentListener(){
                         public   void   adjustmentValueChanged(AdjustmentEvent   e)   {
                        itemPane.repaint();}
                        });
                 repaint();
                  }   
              });

}

GanttChart代码protected void paintComponent(Graphics g) {
// TODO Auto-generated method stub
super.paintComponent(g);
g.fillRect(0, 1,GanttChart.height,GanttChart.chartCount*GanttChart.chartheight);
g.setColor(Color.YELLOW);
g.setFont(new Font("", Font.BOLD, 12));
int xx;
JButton jButton=null;
for(int i=1;i<=GanttChart.chartCount;i++)
{
xx = i * GanttChart.chartheight;
GanttChart.chartheight,GanttHeader.titlePanelWidth,xx);
jButton=new JButton();
jButton.setSize(this.getSize().width/2,10);
jButton.setBounds(50,xx-35,GanttHeader.titlePanelWidth/2,15);

this.add(jButton);
g.drawLine(0,xx,GanttHeader.titlePanelWidth,xx);
}
}

Answer 3

就是我用Button去显示工作进度，所以会有很多的Button放到Panel里，

Answer 4

怎么能把组件构造的方法放在paintComponent中，这个方法是一直在调用的。
你应该把所有Button的创建放在这个面板的构造函数中。让paintComponent只是去填充颜色而已。

Answer 5

嗯  有道理·     你就是想產生多個jbutton   這段代碼 完全可以放到外面～   和paint沒啥關系·