在NetBeans中运行代码时如何更改jlabel背景颜色

Question

I want to develop simulator using netbeans. so i choose insertion sort.i there i need to change the jlabel background color when running the code.that means i want to color line by line when running the code.for that case i use the below code segment.there are more codes.but i mention only relavent part.how do i change the jlabel color!

for (j = 1; j < 7; j++) { sleep();

        key = numArray[j];
        jLabel11Algo2.setBackground(Color.red);

        sleep();
        jLabel11Algo2.setBackground(Color.white);

        System.out.println(key);

Answer 1

First you need to make the label opaque so its background will be painted:

label.setOpaque(true);

Secondly to do your animation you need to use a Swing Timer to do the animation, not Thread.sleep().

You can't use Thread.sleep() because that will cause the Event Dispatch Thread to sleep which means the GUI can't repaint itself. Read the section from the Swing tutorial on Concurrency for more information.