C# Signature:
[DllImport("shlwapi.dll", CharSet=CharSet.Auto)]
static extern string PathCombine([Out] StringBuilder lpszDest, string lpszDir, string lpszFile);
VB.NET Signature
Declare Unicode Function PathCombine Lib "shlwapi.dll" Alias "PathCombineW" (<MarshalAs(UnmanagedType.LPTStr)> PathOut As System.Text.StringBuilder, <MarshalAs(UnmanagedType.LPTStr)> PathIn As String, <MarshalAs(UnmanagedType.LPTStr)> More As String) As IntPtr
VB Signature:
Declare Function PathCombine Lib "shlwapi.dll" Alias "PathCombineA" (ByVal szDest As String, ByVal lpszDir As String, ByVal lpszFile As String) As Long
Notes:
This is similar, but not identical, to PathAppend and Path.Combine. For example, combining "C:\foo" with "\bar" yields "C:\bar" rather than "C:\foo\bar" or "\bar" respectively.
Current signature is incorrect, because return value is string and CLR trying to release the same string twice (return value and lpszDest). I have unxpected crashes. I think that type of return value should change to IntPtr. This page contains some discussion about this problem: http://objectmix.com/dotnet/747522-p-invoke-signature-pathcombine.html
Tips & Tricks:
Please add some!
Sample Code:
[DllImport("shlwapi.dll", CharSet = CharSet.Auto)]
static extern string PathCombine([Out] StringBuilder lpszDest, string lpszDir, string lpszFile);
public static string GetAbsolutePath(string basePath, string relativePath)
{
StringBuilder sb = new StringBuilder();
return PathCombine(sb,basePath,relativePath);
}
//nunit test case
[Test]
public void TestGetAbsolutePath()
{
Assert.AreEqual(@"c:\abc\123.txt",IO.GetAbsolutePath(@"c:\abc\","123.txt"),"Test 1");
Assert.AreEqual(@"c:\abc\123.txt", IO.GetAbsolutePath(@"c:\abc\efg\", @"..\123.txt"), "Test 1");
}
Alternative Managed API:
