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10 Replies Latest reply: Jan 7, 2005 9:23 AM by 807596 RSS

why JComboBox not shown?

807596 Newbie
Currently Being Moderated
I use a JPanel, and tried to show a JComboBox on it.
But somehow the JComboBox is not shown. Need
help here. Thank you.
  • 1. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    Show us the code. It's impossible to say what the problem is from your description.
  • 2. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    It is not that the JComboBox is not shown, but it is not shown correctly since
    the down-pointing solid triangle is not shown and the JComboBox is not
    activated until I moved the mouse pointer to a different area or clicked the
    mouse. I did use setEnabled(true). Here is the code:
        modeType.addItem("Phi");
        modeType.addItem("Pump_probe delay");
        modeType.setSelectedIndex(0);
        modeType.setEnabled(true);
    
        delayMode.setBounds(167, 210, 90, 30);
        add(delayMode, null);
  • 3. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    Error in my previous code. The right one is:
        modeType.addItem("Phi");
        modeType.addItem("Pump_probe delay");
        modeType.setSelectedIndex(0);
        modeType.setEnabled(true);
    
        modeType.setBounds(40, 150, 120, 30);
        add(modeType, null);
  • 4. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    Well, that little code snippet is pretty useless without its context. I guess modeType is your combobox, yes? What are you adding it to? And why are you setting its bounds, have you set the Layout Manager to null? Why?
  • 5. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    modeType is my jCOmboBox, and the layoutManage is set to null.
  • 6. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    Just for fun, I wrote a small test program that included the following lines:
    modeType.addItem("Phi");
    modeType.addItem("Pump_probe delay");
    modeType.setSelectedIndex(0);
    modeType.setEnabled(true);
    
    modeType.setBounds(40, 150, 120, 30);
    add(modeType, null);
    As you can see, those lines are identical to the code you posted. modeType is a JComboBox that I'm adding to a JPanel that has no layout manager. In my program the combobox shows up perfectly.

    This tells us that the problem with your code is not those 6 lines, but something else. And without seeing the rest of your code it's awfully difficult to guess what it can be.
  • 7. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    Try maximizing your frame or anything else.
  • 8. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    If I run the program alone (changed from JPanel to JFrame), the JComboBox
    does show the down-pointing triangle. Problaby my other programs cost
    the problem of not showing. Thank you for your interest.
  • 9. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    I have found that after I click mouse once anywhere in the displayed area (the outer most--large),
    the down-pointing triangle is shown. So is this a Java bug?
  • 10. Re: why JComboBox not shown?
    807596 Newbie
    Currently Being Moderated
    So is this a Java bug?
    Probably not. My money would be on that the bug is in your code. But you won't show us your code so who knows?