求助 我的JComboBox可以下拉，但不能显示下拉箭头了。

grubby4k 2009-11-10 05:15:20 
 private void jbInit()

    {

        this.getContentPane().add(pnlMain);

        pnlMain.setLayout(borderLayout1);

        pnlMain.setBorder(BorderFactory.createEmptyBorder(12, 12, 12, 12));

        pnlMain.add(pnlCenter, BorderLayout.CENTER);

        pnlMain.add(pnlSouth, BorderLayout.SOUTH);

        pnlSouth.setLayout(flowLayout1);

        flowLayout1.setAlignment(FlowLayout.RIGHT);

        pnlSouth.add(btnRefresh);

        pnlSouth.add(btnSet);

        pnlSouth.add(btnClose);

        pnlSouth.add(btnHelp);

        btnRefresh.setText("刷新");

        btnRefresh.setSize(new Dimension(83, 23));

        btnRefresh.setMnemonic('R');

        btnRefresh.addActionListener(new java.awt.event.ActionListener()

        {

            public void actionPerformed(ActionEvent e)

            {

                btnRefresh_actionPerformed(e);

            }

        });

        btnSet.setText("设置");

        btnSet.setSize(new Dimension(83, 23));

        btnSet.setMnemonic('S');

        btnSet.addActionListener(new java.awt.event.ActionListener()

        {

            public void actionPerformed(ActionEvent e)

            {

                btnSet_actionPerformed(e);

            }

        });

        btnClose.setText("关闭");

        btnClose.setSize(new Dimension(83, 23));

        btnClose.setMnemonic('C');

        btnClose.addActionListener(new java.awt.event.ActionListener()

        {

            public void actionPerformed(ActionEvent e)

            {

                btnClose_actionPerformed(e);

            }

        });

        btnHelp.setText("帮助");

        btnHelp.setSize(new Dimension(83, 23));

        btnHelp.setMnemonic('H');

        btnHelp.addActionListener(new java.awt.event.ActionListener()

        {

            public void actionPerformed(ActionEvent e)

            {

                btnHelp_actionPerformed(e);

            }

        });

        

        pnlCenter.setLayout(borderLayout2);

        pnlCenter.setBorder(border1);

        pnlCenter.add(pnlCNorth, BorderLayout.NORTH);

        pnlCenter.add(pnlCCenter, BorderLayout.CENTER);

        pnlCenter.add(pnlCSouth, BorderLayout.SOUTH);

        pnlCNorth.setBorder(border2);

        pnlCNorth.setLayout(gridBagLayout1);

        lblZxAnMldAdminStatus.setText("MLD协议使能");

        lblZxAnMldAging.setText("老化时间");

        lblZxAnMldWorkingMode.setText("工作模式");

        lblZxAnMldMcastInAllVlan.setText("跨VLAN使能");

        lblZxAnMldBandwidthCtrl.setText("带宽使能");

        lblZxAnMldHostTrackOnOff.setText("主机跟踪使能");

        lblZxAnMldGeneralLeaveGrpAddr.setText("通用离开组播地址");

        lblZxAnMldGroupThreshold.setText("最大组播组门限");

        pnlCNorth.add(lblZxAnMldAdminStatus, new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(cmbZxAnMldAdminStatus, new GridBagConstraints(1, 0, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldAging, new GridBagConstraints(2, 0, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(txtZxAnMldAging, new GridBagConstraints(3, 0, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldWorkingMode, new GridBagConstraints(0, 1, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(cmbZxAnMldWorkingMode, new GridBagConstraints(1, 1, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldMcastInAllVlan, new GridBagConstraints(2, 1, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(cmbZxAnMldMcastInAllVlan, new GridBagConstraints(3, 1, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldBandwidthCtrl, new GridBagConstraints(0, 2, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(cmbZxAnMldBandwidthCtrl, new GridBagConstraints(1, 2, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldHostTrackOnOff, new GridBagConstraints(2, 2, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(cmbZxAnMldHostTrackOnOff, new GridBagConstraints(3, 2, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldGeneralLeaveGrpAddr, new GridBagConstraints(0, 3, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(txtZxAnMldGeneralLeaveGrpAddr, new GridBagConstraints(1, 3, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(lblZxAnMldGroupThreshold, new GridBagConstraints(2, 3, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCNorth.add(txtZxAnMldGroupThreshold, new GridBagConstraints(3, 3, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));



        pnlCCenter.setBorder(border3);

        pnlCCenter.setLayout(gridBagLayout2);

        lblZxAnMldRobustnessVariable.setText("健壮性变量");

        lblZxAnMldQueryInterval.setText("查询间隔");

        lblZxAnMldQueryMaxResponseTime.setText("查询最大响应时间");

        lblZxAnMldLastMembQueryInterval.setText("最后成员查询间隔");

        lblZxAnMldLastMembQueryCount.setText("最后成员查询记数");

        lblZxAnMldUnsolicitedReportInterv.setText("主动报告间隔时间");

        pnlCCenter.add(lblZxAnMldRobustnessVariable, new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(cmbZxAnMldRobustnessVariable, new GridBagConstraints(1, 0, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(lblZxAnMldQueryInterval, new GridBagConstraints(2, 0, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(txtZxAnMldQueryInterval, new GridBagConstraints(3, 0, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(lblZxAnMldQueryMaxResponseTime, new GridBagConstraints(0, 1, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(txtZxAnMldQueryMaxResponseTime, new GridBagConstraints(1, 1, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(lblZxAnMldLastMembQueryInterval, new GridBagConstraints(2, 1, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(txtZxAnMldLastMembQueryInterval, new GridBagConstraints(3, 1, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(lblZxAnMldLastMembQueryCount, new GridBagConstraints(0, 2, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(cmbZxAnMldLastMembQueryCount, new GridBagConstraints(1, 2, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(lblZxAnMldUnsolicitedReportInterv, new GridBagConstraints(2, 2, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCCenter.add(txtZxAnMldUnsolicitedReportInterv, new GridBagConstraints(3, 2, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCSouth.setBorder(border4);

        pnlCSouth.setLayout(gridBagLayout3);

        lblZxAnMcastIpv6CdrServerIP.setText("接收服务器地址");

        lblNull1.setText("     ");

        lblNull2.setText("     ");

        pnlCSouth.add(lblZxAnMcastIpv6CdrServerIP, new GridBagConstraints(0, 0, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCSouth.add(txtZxAnMcastIpv6CdrServerIP, new GridBagConstraints(1, 0, 1, 1, 1.0, 0.0

            , GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL, new Insets(6, 6, 6, 6), 0, 0));

        pnlCSouth.add(lblNull1,  new GridBagConstraints(2, 0, 1, 1, 1.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

        pnlCSouth.add(lblNull2,  new GridBagConstraints(3, 0, 1, 1, 0.0, 0.0

            , GridBagConstraints.WEST, GridBagConstraints.NONE, new Insets(6, 6, 6, 6), 0, 0));

    }


用的是GridBagConstraint布局
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tsc2008 2010-02-25
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今天用到JComboBox，需要将所有项删除，然后重新加，结果点出一个removeAll来，直接就用了。一运行才发现，连右边的下拉箭头也给remove掉了。惊出一身汗，赶紧查文档，唉，就在下面有一个removeAllItems方法。看来不看文档就是不行啊。特地拿出来，记住它

引用

removeAllItems
public void removeAllItems()
从项列表中移除所有项。



引用

removeAll
public void removeAll()从此容器中移除所有组件。此方法还通知布局管理器，通过 removeLayoutComponent 方法从此容器的布局中移除这些组件。
whut0802 2009-11-11
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头有点晕。。。还是帮顶下
grubby4k 2009-11-11
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顶一下
grubby4k 2009-11-10
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怎么就没人呢~？这么诡异的问题呀
grubby4k 2009-11-10
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顶一下~
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