Question

If I have an absolute DirectoryInfo path and a relative FileInfo path, how can I combine them into an absolute FileInfo path?

For example:

var absoluteDir = new DirectoryInfo(@"c:\dir");
var relativeFile = new FileInfo(@"subdir\file");
var absoluteFile = new FileInfo(absoluteDir, relativeFile); //-> How to get this done?

Answer 1

If absoluteDir and relativeFile exist for the sole purpose of being used to create absoluteFile, use should probably stick with plain strings for them and leaving only absoluteFile as a FileInfo.

var absoluteDir = @"c:\dir"; 
var relativeFile = @"subdir\file"; 
var absoluteFile = new FileInfo(Path.Combine(absoluteDir, relativeFile)); 

Edit:
If otherwise you really need them to be typed, then you should use Path.Combine applied to the OriginalPath of each of them, which you can access such as in:

var absoluteDir = new DirectoryInfo(@"c:\dir");
var relativeFile = new FileInfo(@"subdir\file");
var absoluteFile = new FileInfo(Path.Combine(absoluteDir.ToString(), relativeFile.ToString()));

The OriginalPath property can not be access directly because of the "protected" statuts.