Now ZipExtractor will suggest process that is holding lock on the fil…

…e so user can exit from it.

ZipExtractor/FileUtil.cs

@@ -0,0 +1,151 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace ZipExtractor
+{
+    // https://stackoverflow.com/a/20623302/1273550
+    public static class FileUtil
+    {
+        [StructLayout(LayoutKind.Sequential)]
+        struct RM_UNIQUE_PROCESS
+        {
+            public int dwProcessId;
+            public System.Runtime.InteropServices.ComTypes.FILETIME ProcessStartTime;
+        }
+
+        const int RmRebootReasonNone = 0;
+        const int CCH_RM_MAX_APP_NAME = 255;
+        const int CCH_RM_MAX_SVC_NAME = 63;
+
+        enum RM_APP_TYPE
+        {
+            RmUnknownApp = 0,
+            RmMainWindow = 1,
+            RmOtherWindow = 2,
+            RmService = 3,
+            RmExplorer = 4,
+            RmConsole = 5,
+            RmCritical = 1000
+        }
+
+        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
+        struct RM_PROCESS_INFO
+        {
+            public RM_UNIQUE_PROCESS Process;
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_APP_NAME + 1)]
+            public string strAppName;
+
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = CCH_RM_MAX_SVC_NAME + 1)]
+            public string strServiceShortName;
+
+            public RM_APP_TYPE ApplicationType;
+            public uint AppStatus;
+            public uint TSSessionId;
+            [MarshalAs(UnmanagedType.Bool)] public bool bRestartable;
+        }
+
+        [DllImport("rstrtmgr.dll", CharSet = CharSet.Unicode)]
+        static extern int RmRegisterResources(uint pSessionHandle,
+            UInt32 nFiles,
+            string[] rgsFilenames,
+            UInt32 nApplications,
+            [In] RM_UNIQUE_PROCESS[] rgApplications,
+            UInt32 nServices,
+            string[] rgsServiceNames);
+
+        [DllImport("rstrtmgr.dll", CharSet = CharSet.Auto)]
+        static extern int RmStartSession(out uint pSessionHandle, int dwSessionFlags, string strSessionKey);
+
+        [DllImport("rstrtmgr.dll")]
+        static extern int RmEndSession(uint pSessionHandle);
+
+        [DllImport("rstrtmgr.dll")]
+        static extern int RmGetList(uint dwSessionHandle,
+            out uint pnProcInfoNeeded,
+            ref uint pnProcInfo,
+            [In, Out] RM_PROCESS_INFO[] rgAffectedApps,
+            ref uint lpdwRebootReasons);
+
+        /// <summary>
+        /// Find out what process(es) have a lock on the specified file.
+        /// </summary>
+        /// <param name="path">Path of the file.</param>
+        /// <returns>Processes locking the file</returns>
+        /// <remarks>See also:
+        /// http://msdn.microsoft.com/en-us/library/windows/desktop/aa373661(v=vs.85).aspx
+        /// http://wyupdate.googlecode.com/svn-history/r401/trunk/frmFilesInUse.cs (no copyright in code at time of viewing)
+        /// 
+        /// </remarks>
+        public static List<Process> WhoIsLocking(string path)
+        {
+            string key = Guid.NewGuid().ToString();
+            List<Process> processes = new List<Process>();
+
+            int res = RmStartSession(out var handle, 0, key);
+
+            if (res != 0)
+                throw new Exception("Could not begin restart session.  Unable to determine file locker.");
+
+            try
+            {
+                const int ERROR_MORE_DATA = 234;
+                uint pnProcInfo = 0,
+                    lpdwRebootReasons = RmRebootReasonNone;
+
+                string[] resources = new string[] {path}; // Just checking on one resource.
+
+                res = RmRegisterResources(handle, (uint) resources.Length, resources, 0, null, 0, null);
+
+                if (res != 0)
+                    throw new Exception("Could not register resource.");
+
+                //Note: there's a race condition here -- the first call to RmGetList() returns
+                //      the total number of process. However, when we call RmGetList() again to get
+                //      the actual processes this number may have increased.
+                res = RmGetList(handle, out var pnProcInfoNeeded, ref pnProcInfo, null, ref lpdwRebootReasons);
+
+                if (res == ERROR_MORE_DATA)
+                {
+                    // Create an array to store the process results
+                    RM_PROCESS_INFO[] processInfo = new RM_PROCESS_INFO[pnProcInfoNeeded];
+                    pnProcInfo = pnProcInfoNeeded;
+
+                    // Get the list
+                    res = RmGetList(handle, out pnProcInfoNeeded, ref pnProcInfo, processInfo, ref lpdwRebootReasons);
+
+                    if (res == 0)
+                    {
+                        processes = new List<Process>((int) pnProcInfo);
+
+                        // Enumerate all of the results and add them to the 
+                        // list to be returned
+                        for (int i = 0; i < pnProcInfo; i++)
+                        {
+                            try
+                            {
+                                processes.Add(Process.GetProcessById(processInfo[i].Process.dwProcessId));
+                            }
+                            // catch the error -- in case the process is no longer running
+                            catch (ArgumentException)
+                            {
+                            }
+                        }
+                    }
+                    else
+                        throw new Exception("Could not list processes locking resource.");
+                }
+                else if (res != 0)
+                    throw new Exception("Could not list processes locking resource. Failed to get size of result.");
+            }
+            finally
+            {
+                RmEndSession(handle);
+            }
+
+            return processes;
+        }
+    }
+}

ZipExtractor/FormMain.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.IO;
@@ -86,7 +87,7 @@ private void FormMain_Shown(object sender, EventArgs e)
 #else
                     // Open an existing zip file for reading.
                     var zip = ZipStorer.Open(args[1], FileAccess.Read);
-
+                    
                     // Read the central directory collection.
                     var entries = zip.ReadCentralDir();
 #endif
@@ -116,12 +117,15 @@ private void FormMain_Shown(object sender, EventArgs e)
                             bool notCopied = true;
                             while (notCopied)
                             {
+                                string filePath = String.Empty;
                                 try
                                 {
 #if NET45
-                                    entry.ExtractToFile(Path.Combine(path, entry.FullName), true);
+                                    filePath = Path.Combine(path, entry.FullName);
+                                    entry.ExtractToFile(filePath, true);
 #else
-                                    zip.ExtractFile(entry, Path.Combine(path, entry.FilenameInZip));
+                                    filePath = Path.Combine(path, entry.FilenameInZip);
+                                    zip.ExtractFile(entry, filePath);
 #endif
                                     notCopied = false;
                                 }
@@ -132,12 +136,44 @@ private void FormMain_Shown(object sender, EventArgs e)
                                     var errorCode = Marshal.GetHRForException(exception) & 0x0000FFFF;
                                     if (errorCode == errorSharingViolation || errorCode == errorLockViolation)
                                     {
-                                        Thread.Sleep(5000);
                                         retries++;
                                         if (retries > MaxRetries)
                                         {
                                             throw;
                                         }
+
+                                        List<Process> lockingProcesses = null;
+                                        if (Environment.OSVersion.Version.Major >= 6 && retries >= 2)
+                                        {
+                                            try
+                                            {
+                                                lockingProcesses = FileUtil.WhoIsLocking(filePath);
+                                            }
+                                            catch (Exception)
+                                            {
+                                                // ignored
+                                            }
+                                        }
+
+                                        if (lockingProcesses == null)
+                                        {
+                                            Thread.Sleep(5000);
+                                        }
+                                        else
+                                        {
+                                            foreach (var lockingProcess in lockingProcesses)
+                                            {
+                                                var dialogResult = MessageBox.Show(
+                                                    string.Format(Resources.FileStillInUseMessage,
+                                                        lockingProcess.ProcessName, filePath),
+                                                    Resources.FileStillInUseCaption,
+                                                    MessageBoxButtons.RetryCancel, MessageBoxIcon.Error);
+                                                if (dialogResult == DialogResult.Cancel)
+                                                {
+                                                    throw;
+                                                }
+                                            }
+                                        }
                                     }
                                     else
                                     {

ZipExtractor/Properties/Resources.resx

@@ -120,6 +120,12 @@
   <data name="CurrentFileExtracting" xml:space="preserve">
     <value>Extracting {0}</value>
   </data>
+  <data name="FileStillInUseCaption" xml:space="preserve">
+    <value>Unable to update the file!</value>
+  </data>
+  <data name="FileStillInUseMessage" xml:space="preserve">
+    <value>{0} is still open and it is using "{1}". Please close the process manually and press Retry.</value>
+  </data>
   <assembly alias="System.Windows.Forms" name="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
   <data name="ZipExtractor" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\Resources\ZipExtractor.png;System.Drawing.Bitmap, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>