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Thread: Variable updates after loop

  1. #1
    Junior Member
    Join Date
    Jan 2011
    Thanked 0 Times in 0 Posts

    Default Variable updates after loop

    So I'm working on adding a progress bar to my app, and I have all the variables created to track the progress of a download, but when I try to edit the variables in a while loop they do not update until after the loop is finished. Below is a list of what happens.

    Download function begins
    I set the total bytes to the file size
    I set the current bytes to 0
    While loop begins
    I add 1 for each byte that is copied
    After 1 million bytes are copied I call the code below
    I print the current bytes and it displays the correct number
    I call the repaint function
    Inside the paint function I print the current bytes and it displays 0
    loop ends
    download function ends
    paint function is called later
    The print inside the paint function now shows the total current bytes were downloaded

    Does anyone know why the paint function is not reading the real value set in the loop until after the loop is over, and if so how do i fix this problem?

  2. #2
    Join Date
    Oct 2011
    Thanked 3 Times in 3 Posts

    Default Re: Variable updates after loop

    Do you use any threads? If not, that is the problem, because the progress bar's GUI is freezing until the download tasks completes. You need to create two threads:
    - one for running the download task.
    - one for update the progress bar.

    java exception
    Last edited by hns1984; January 11th, 2012 at 06:58 PM.

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