Add NoTestFileCreate property in FileDialog

src/Microsoft.DotNet.Wpf/src/PresentationFramework/Microsoft/Win32/FileDialog.cs

@@ -190,6 +190,22 @@ public bool CheckPathExists
             }
         }
 
+        /// <summary>
+        /// The file is not created before the dialog box is closed. This flag should be specified if the application saves the file on a create-nonmodify network share. When an application specifies this flag, the library does not check for write protection, a full disk, an open drive door, or network protection. Applications using this flag must perform file operations carefully, because a file cannot be reopened once it is closed. 
+        /// </summary>
+        public bool NoTestFileCreate
+        {
+            get
+            {
+                return GetOption(NativeMethods.OFN_NOTESTFILECREATE);
+            }
+            set
+            {
+
+                SetOption(NativeMethods.OFN_NOTESTFILECREATE, value);
+            }
+        }
+
         /// <summary>
         /// The AddExtension property attempts to determine the appropriate extension
         /// by using the selected filter.  The DefaultExt property serves as a fallback - 

src/Microsoft.DotNet.Wpf/src/Shared/MS/Win32/NativeMethodsCLR.cs

@@ -1411,7 +1411,8 @@ public const int
         OFN_EXPLORER = 0x00080000,
         OFN_NODEREFERENCELINKS = 0x00100000,
         OFN_ENABLESIZING = 0x00800000,
-        OFN_USESHELLITEM = 0x01000000;
+        OFN_USESHELLITEM = 0x01000000,
+        OFN_NOTESTFILECREATE = 0x00010000;
 
 #if never
         public const int OLEIVERB_PRIMARY = 0,