Removing items in a container

Question

When I try to remove Components from a Container, I use this code.

private static void clear(){
    for (int i = con.getComponentCount() - 1; i >= 1; i--){
        con.remove(i);
    }
}

When I call this function, the function acts as if it has done nothing, but crashes it as if its overloading. It gives no error. But when I put con.getComponent(i).setVisible(false); in the code it works, but I want to REMOVE the components. Halp?

I am assuming this function is in a class, and that con is a member variable of that class? Can you include the line that declares and instantiates that variable? Also, when it crashes, there is no error? — Nathaniel Ford, May 02 '12 at 18:24
@NathanielFord: it's probably a `java.awt.Container` instance. — Pablo Santa Cruz, May 02 '12 at 18:25
I hope that isn't really a mutable static. (Are you multithreading that? And why don't you want to remove component 0?) — Tom Hawtin - tackline, May 02 '12 at 18:33

score 3 · Answer 1 · answered May 02 '12 at 18:24

3

Try using this:

while (con.getComponentCount()>0) {
    con.remove(0);
}

answered May 02 '12 at 18:24

Pablo Santa Cruz

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I like this approach better, in general. However, how could the above trigger an IOOBE? – May 02 '12 at 18:27
@pst: right. didn't notice before `i` variable was decrementing on the loop. – Pablo Santa Cruz May 02 '12 at 18:29

score 2 · Accepted Answer · answered May 02 '12 at 18:24

2

After you are done removing the components you want to remove, call Container.validate(); Container.repaint(); Actually, you might want to revalidate more than that.

answered May 02 '12 at 18:24

ControlAltDel

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So is the problem resolved? If so, you should mark the best solution as correct. This will close the issue – ControlAltDel May 02 '12 at 19:07

score 1 · Answer 3 · answered May 02 '12 at 18:26

1

Have you tried containerObject.repaint() after removing the components?

answered May 02 '12 at 18:26

Silviu Burcea

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score 0 · Answer 4 · answered May 02 '12 at 18:31

0

Assuming that con is an awt Container, you can call

con.removeAll();

that removes all contained components at once.

answered May 02 '12 at 18:31

Andrea Parodi

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Removing items in a container

4 Answers4