How to properly assemble a valid xlsx file from its internal sub-components?

Question

I\'m trying to create an xlsx file programmatically on iOS. Since the internal data of xlsx files is basically stored in separate xml files, I tried to recreate xlsx structu

Answer 1

I was using WinZip 15.5 to rezip xlsx xml files. Different compression types produced different results.

Note: The original file size was 555KB.

• .Zip: New filesize 3,279KB (!). Excel can open.
• .Zipx: New filesize 341KB. Excel couldn't open.
• Zip SuperFast: New filesize 606KB. Excel can open.
• Zip Enh. Deflate: New filesize 429KB. Excel couldn't open.
• Zipx bzip2: New filesize 333KB. Excel couldn't open.
• Zipx LZMA: New filesize 328KB. Excel couldn't open.
• Zipx PPMd: New filesize 317KB. Excel couldn't open.

Conclusion: Zip SuperFast is the only effective compression format.