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trying to convert the libpng to vb.NET code RRS feed

  • Question

  • as mentioned in the title, i am facing an accessviolation exception if the line:

    png_read_info(png, info)

    i have searched on google, i found that this problem is related to the multi-threaded application and the libpng dll, in c++ app we can use the /md setting but i am in vb.net.

    Wednesday, April 17, 2019 5:17 PM

All replies

  • Hi,

    I found the following article,it is about C++,I hope you can get heip.

    https://stackoverflow.com/questions/22774265/libpng-crashes-on-png-read-info

    Best Regards,

    Alex


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    Thursday, April 18, 2019 6:07 AM
    Moderator
  • yes the link is about C++ , they are talking about changing the app from single-threaded to multi-threaded, but i am on vb.NET , how can i change to multi-threaded vb.NET app just as the libpng?
    Thursday, April 18, 2019 7:46 AM
  • It works by using a custom function to read data, with png_set_read_fn

    It must be declared with

     <UnmanagedFunctionPointer(CallingConvention.Cdecl)>

    (tested on Windows 10/VS 2015 with last LibPng version ("1.6.37") that I have recompiled for testing)


    • Edited by Castorix31 Friday, April 19, 2019 11:18 AM
    Friday, April 19, 2019 11:17 AM