。//============================================================================================================
// Microsoft Updater Application Block for .NET
// http://msdn.microsoft.com/library/en-us/dnbda/html/updater.asp
//
// FileUtility.cs
//
// Contains the implementation of the FileUtility helper class.
//
// For more information see the Updater Application Block Implementation Overview.
//
//============================================================================================================
// Copyright ?Microsoft Corporation. All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//============================================================================================================
using System;
using System.IO;
using System.Runtime.InteropServices;
namespace Microsoft.ApplicationBlocks.Updater.Utilities
{
/// <summary>
/// Indicates how to proceed with the move file operation.
/// </summary>
[Flags]
public enum MoveFileFlag : int
{
/// <summary>
/// Perform a default move funtion.
/// </summary>
None = 0x00000000,
/// <summary>
/// If the target file exists, the move function will replace it.
/// </summary>
ReplaceExisting = 0x00000001,
/// <summary>
/// If the file is to be moved to a different volume,
/// the function simulates the move by using the CopyFile and DeleteFile functions.
/// </summary>
CopyAllowed = 0x00000002,
/// <summary>
/// The system does not move the file until the operating system is restarted.
/// The system moves the file immediately after AUTOCHK is executed, but before
/// creating any paging files. Consequently, this parameter enables the function
/// to delete paging files from previous startups.
/// </summary>
DelayUntilReboot = 0x00000004,
/// <summary>
/// The function does not return until the file has actually been moved on the disk.
/// </summary>
WriteThrough = 0x00000008,
/// <summary>
/// Reserved for future use.
/// </summary>
CreateHardLink = 0x00000010,
/// <summary>
/// The function fails if the source file is a link source, but the file cannot be tracked after the move. This situation can occur if the destination is a volume formatted with the FAT file system.
/// </summary>
FailIfNotTrackable = 0x00000020,
}
/// <summary>
/// Provides certain utilities used by configuration processors, such as correcting file paths.
/// </summary>
public sealed class FileUtility
{
#region Constructor
/// <summary>
/// Default constructor.
/// </summary>
private FileUtility()
{
}
#endregion
#region Public members
/// <summary>
/// Returns whether the path is a UNC path.
/// </summary>
/// <param name="path">The path string.</param>
/// <returns><c>true</c> if the path is a UNC path.</returns>
public static bool IsUncPath( string path )
{
// FIRST, check if this is a URL or a UNC path; do this by attempting to construct uri object from it
Uri url = new Uri( path );
if( url.IsUnc )
{
// it is a unc path, return true
return true;
}
else
{
return false;
}
}
/// <summary>
/// Takes a UNC or URL path, determines which it is (NOT hardened against bad strings, assumes one or the other is present)
/// and returns the path with correct trailing slash: backslash for UNC or
/// slash mark for URL.
/// </summary>
/// <param name="path">The URL or UNC string.</param>
/// <returns>Path with correct terminal slash.</returns>
public static string AppendSlashUrlOrUnc( string path )
{
if( IsUncPath( path ) )
{
// it is a unc path, so decorate the end with a back-slash (to correct misconfigurations, defend against trivial errors)
return AppendTerminalBackslash( path );
}
else
{
// assume URL here
return AppendTerminalForwardSlash( path );
}
}
/// <summary>
/// If not present appends terminal backslash to paths.
/// </summary>
/// <param name="path">A path string; for example, "C:/AppUpdaterClient".</param>
/// <returns>A path string with trailing backslash; for example, "C:/AppUpdaterClient/".</returns>
public static string AppendTerminalBackslash( string path )
{
if( path.IndexOf( Path.DirectorySeparatorChar, path.Length - 1 ) == -1 )
{
return path + Path.DirectorySeparatorChar;
}
else
{
return path;
}
}
/// <summary>
/// Appends a terminal slash mark if there is not already one; returns corrected path.
/// </summary>
/// <param name="path">The path that may be missing a terminal slash mark.</param>
/// <returns>The corrected path with terminal slash mark.</returns>
public static string AppendTerminalForwardSlash( string path )
{
if( path.IndexOf( Path.AltDirectorySeparatorChar, path.Length - 1 ) == -1 )
{
return path + Path.AltDirectorySeparatorChar;
}
else
{
return path;
}
}
/// <summary>
///