Fix file access issues in LocalFileDownloader

Remove unneeded .Close() calls, too. Also set FileShare to .Read just for safety.

Closes #512

Co-Authored-By: sdijoseph <6656812+sdijoseph@users.noreply.github.com>

Author: Deadpikle

src/NetSparkle/Downloaders/LocalFileDownloader.cs

@@ -109,7 +109,7 @@ private async Task CopyFileAsync(string sourceFile, string destinationFile, Canc
                 using (var sourceStream =
                       new FileStream(sourceFile, FileMode.Open, FileAccess.Read, FileShare.Read, bufferSize, fileOptions))
                 using (var destinationStream =
-                      new FileStream(destinationFile, FileMode.CreateNew, FileAccess.Write, FileShare.None, bufferSize, fileOptions))
+                      new FileStream(destinationFile, FileMode.CreateNew, FileAccess.Write, FileShare.Read, bufferSize, fileOptions))
                 {
                     IsDownloading = true;
                     var wasCanceled = false;
@@ -127,8 +127,8 @@ private async Task CopyFileAsync(string sourceFile, string destinationFile, Canc
                         UpdateDownloadProgress(totalRead, totalFileLength);
                     }
                     IsDownloading = false;
-                    DownloadFileCompleted?.Invoke(this, new AsyncCompletedEventArgs(null, wasCanceled, null));
                 }
+                DownloadFileCompleted?.Invoke(this, new AsyncCompletedEventArgs(null, wasCanceled, null));
             }
             catch (Exception e)
             {

src/NetSparkle/Downloaders/WebClientFileDownloader.cs

@@ -161,7 +161,7 @@ private async Task StartFileDownloadAsync(Uri uri, string downloadFilePath)
                         }
                         return;
                     }
-                    using (FileStream fileStream = new FileStream(downloadFilePath, FileMode.Create, FileAccess.Write, FileShare.None, 8192, true))
+                    using (FileStream fileStream = new FileStream(downloadFilePath, FileMode.Create, FileAccess.Write, FileShare.Read, 8192, true))
                     using (Stream contentStream = await response.Content.ReadAsStreamAsync())
                     {
                         long totalLength = response.Content.Headers.ContentLength ?? 0;
@@ -191,11 +191,9 @@ private async Task StartFileDownloadAsync(Uri uri, string downloadFilePath)
                             UpdateDownloadProgress(totalRead, totalLength);
                         } while (IsDownloading);
                         IsDownloading = false;
-                        fileStream.Close();
-                        contentStream.Close();
-                        UpdateDownloadProgress(totalRead, totalLength);
-                        DownloadFileCompleted?.Invoke(this, new AsyncCompletedEventArgs(null, false, null));
                     }
+                    UpdateDownloadProgress(totalRead, totalLength);
+                    DownloadFileCompleted?.Invoke(this, new AsyncCompletedEventArgs(null, false, null));
                 }
             }
             catch (Exception e)