问题
Basically I would like to convert a bitmap to a png using libpng but rather than outputting it to a FILE* I would like to output it to a char*. I have already seen this related post but I don't see where the bitmap data is actually used. Any help would be appreciated.
回答1:
Use the png_set_write_fn function to redirect writes to your own function; this function, which you need to write, can store the output in any way you want.
See the documentation at http://www.libpng.org/pub/png/libpng-manual.txt
来源：https://stackoverflow.com/questions/3739667/help-converting-a-bitmap-to-a-png-in-memory-using-libpng