Bug fix for read-only project files. Behavior:

- Ask for permission to edit a file
- Notify it will be saved
- Save and notify so that the user to prompted to reload the project.

EditProj/EditProjPackage.cs

@@ -15,6 +15,7 @@
 using EnvDTE;
 using System.Collections.Generic;
 using System.Linq;
+using EnvDTE80;
 
 namespace rdomunozcom.EditProj
 {
@@ -44,6 +45,9 @@ public sealed class EditProjPackage : Package
         private DTE dte;
         private IDictionary<string, string> tempToProjFiles;
 
+        // Calling the QueryEditFiles method within the body pops up a query dialog. While the dialog is waiting for the user, the shell automatically can call the method checking for dirtiness and that will call CanEditFile again. To avoid recursion we use the _GettingCheckOutStatus flag as a guard
+        private bool gettingCheckoutStatus = false;
+
         /// <summary>
         /// Default constructor of the package.
         /// Inside this method you can place any initialization code that does not require 
@@ -222,7 +226,22 @@ private void exitCommand_BeforeExecute(string Guid, int ID, object CustomIn, obj
         private void UpdateProjFile(string tempFilePath)
         {
             string contents = ReadFile(tempFilePath);
-            SetFileContents(this.tempToProjFiles[tempFilePath], contents);
+            string projFile = this.tempToProjFiles[tempFilePath];
+            if (CanEditFile(this.tempToProjFiles[tempFilePath]))
+            {
+                NotifyForSave(projFile);
+                SetFileContents(projFile, contents);
+                NotifyDocChanged(projFile);
+            }
+        }
+
+        private void NotifyForSave(string p)
+        {
+            int hr;
+            IVsQueryEditQuerySave2 queryEditQuerySave = (IVsQueryEditQuerySave2)GetService(typeof(SVsQueryEditQuerySave));
+            uint result;
+            hr = queryEditQuerySave.QuerySaveFile(p, 0, null, out result);
+
         }
 
         private static void SetFileContents(string filePath, string content)
@@ -234,5 +253,50 @@ private static string ReadFile(string filePath)
         {
             return File.ReadAllText(filePath);
         }
+
+        private bool CanEditFile(string p)
+        {
+            if (gettingCheckoutStatus) return false;
+
+            try
+            {
+                gettingCheckoutStatus = true;
+
+                IVsQueryEditQuerySave2 queryEditQuerySave =
+                  (IVsQueryEditQuerySave2)GetService(typeof(SVsQueryEditQuerySave));
+
+                string[] documents = { p };
+                uint result;
+                uint outFlags;
+
+                int hr = queryEditQuerySave.QueryEditFiles(
+                  0,
+                  1,
+                  documents,
+                  null,
+                  null,
+                  out result,
+                  out outFlags);
+                if (ErrorHandler.Succeeded(hr) && (result ==
+                  (uint)tagVSQueryEditResult.QER_EditOK))
+                {
+                    return true;
+                }
+            }
+            finally
+            {
+                gettingCheckoutStatus = false;
+            }
+            return false;
+        }
+
+
+        private void NotifyDocChanged(string p)
+        {
+            IVsFileChangeEx fileChangeEx =
+              (IVsFileChangeEx)GetService(typeof(SVsFileChangeEx));
+            int hr;
+            hr = fileChangeEx.SyncFile(p);
+        }
     }
 }