C # example code of absolute path splicing relative path

During project creation, we found that the Path. Combine method can only support directory splicing in the silly way.

Copy codeThe Code is as follows: // absolute path
String absolutePath = @ "C: \ Program Files \ Internet Explorer ";
// Relative path
String relativePath = @ ".. \ TestPath \";
// Expected splicing result
String splicingResult = string. Empty;
Console. writeLine (string. format ("Path. combine (\ "{0} \", \ "{1} \") = \ "{2} \" ", absolutePath, relativePath, Path. combine (absolutePath, relativePath )));

Output result:

The relative path and absolute path are not identified as expected, so we have to use regular expressions to match the relative path for re-stitching. The following methods only support absolute path + relative path.

// Absolute path
String absolutePath = @ "C: \ Program Files \ Internet Explorer ";
// Relative path
String relativePath = @ ".. \ TestPath \";
// Expected splicing result
String splicingResult = string. Empty;
Console. writeLine (string. format ("Path. combine (\ "{0} \", \ "{1} \") = \ "{2} \" ", absolutePath, relativePath, Path. combine (absolutePath, relativePath )));
If (! Path. IsPathRooted (relativePath ))
{
// Match the relative path and the number of directory layers to be pushed up
Regex regex = new Regex (@ "^ \ | ([..] + )");
Int backUp = regex. Matches (relativePath). Count;
List <string> pathes = absolutePath. Split ("\". ToCharArray (). ToList ();
Pathes. RemoveRange (pathes. Count-backUp, backUp );
// Match the file name, matching the number of directories to be appended
Regex = new Regex (@ "^ \ | ([a-zA-Z0-9] + )");
MatchCollection matches = regex. Matches (relativePath );
Foreach (Match match in matches)
{
Pathes. Add (match. Value );
}
// Obtain the drive address from the absolute path.
Pathes [0] = Path. GetPathRoot (absolutePath );
Foreach (string p in pathes)
{
SplicingResult = Path. Combine (splicingResult, p );
}
}
Console. WriteLine (string. Format ("Absolute Path = {0}", absolutePath ));
Console. WriteLine (string. Format ("Relative Path = {0}", relativePath ));
Console. writeLine (string. format ("Path. combine (\ "{0} \", \ "{1} \") = \ "{2} \" ", absolutePath, relativePath, splicingResult ));
Console. ReadLine ();

Output result: