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FindFirstFileEx (kernel32)

C# Signature:

    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern IntPtr FindFirstFileEx(
        string lpFileName,
        FINDEX_INFO_LEVELS fInfoLevelId,
        out WIN32_FIND_DATA lpFindFileData,
        FINDEX_SEARCH_OPS fSearchOp,
        IntPtr lpSearchFilter,
        int dwAdditionalFlags);

VB.NET Signature:

    <DllImport("kernel32.dll", CharSet:=CharSet.Auto)> _
    Private Function FindFirstFileEx(ByVal lpFileName As String, ByVal fInfoLevelId As FINDEX_INFO_LEVELS, ByRef lpFindFileData As WIN32_FIND_DATA, ByVal fSearchOp As FINDEX_SEARCH_OPS, lpSearchFilter As Int32, dwAdditionalFlags As Integer) As Int32
    End Function

The corrent VB signature is:

   <DllImport("kernel32.dll", CharSet:=CharSet.Unicode)> _
    Public Shared Function FindFirstFileExW(ByVal lpFileName As String, ByVal fInfoLevelId As FINDEX_INFO_LEVELS, ByRef lpFindFileData As WIN32_FIND_DATAW, ByVal fSearchOp As FINDEX_SEARCH_OPS, lpSearchFilter As IntPtr, dwAdditionalFlags As Integer) As IntPtr
    End Function

Those 'int32's are IntPtr - and using an Int32 insteade will fail on a 64-bit platform.

User-Defined Types:




// dwAdditionalFlags:
public const int FIND_FIRST_EX_CASE_SENSITIVE= 1;
public const int FIND_FIRST_EX_LARGE_FETCH = 2;



Tips & Tricks:

Please add some!

Sample Code:

    WIN32_FIND_DATA findData;
    FINDEX_INFO_LEVELS findInfoLevel = FINDEX_INFO_LEVELS.FindExInfoStandard;
    int additionalFlags = 0;
    if (Environment.OSVersion.Version.Major >= 6)
    findInfoLevel = FINDEX_INFO_LEVELS.FindExInfoBasic;
    additionalFlags = FIND_FIRST_EX_LARGE_FETCH;

    IntPtr hFile = FindFirstFileEx(
    out findData,
    int error = Marshal.GetLastWin32Error();

    if (hFile.ToInt32() != -1)
        if ((findData.dwFileAttributes & FileAttributes.Directory) != FileAttributes.Directory)
        Console.WriteLine("Found file {0}", findData.cFileName);
    while (FindNextFile(hFile, out findData));


Alternative Managed API:

The FileInfo() class provides managed access to this information. As with all .NET file handling (as of framework 4) it is constrained in terms of the length of filename allowed.


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