问题
When I first saw the System.IOUtils unit with functions like TFile.ReadAllBytes and TFile.ReadAllText and the TStreamReader and TBinaryReader classes in System.Classes I was quite excited to have easy ways to read binary and text files.
After using them for a while I noticed that the default share mode is implicitly fmShareCompat, since they all use TFileStream.Create, but do not explicitly specify a share mode.
Since fmShareCompat is treated as fmShareExclusive on Windows this leads to file locking problems when using them.
Is this an oversight by the Delphi developers? Or is there a reason to not use fmShareDenyWrite by default?
Also why is there no way to specify a share mode?
I am now tempted to write my own version of these classes in order to make them more sharing friendly.
来源：https://stackoverflow.com/questions/23359813/why-do-the-system-ioutils-functions-and-tstreamreader-use-fmsharecompat