添加项目文件。

gong-wpf-dragdrop/src/GongSolutions.WPF.DragDrop/ScrollingMode.cs

@@ -0,0 +1,13 @@
+namespace GongSolutions.Wpf.DragDrop
+{
+    /// <summary>
+    /// Specifies how <see cref="T:System.Windows.Controls.ScrollViewer" /> reacts to drop operation.
+    /// </summary>
+    public enum ScrollingMode
+    {
+        None,
+        HorizontalOnly,
+        VerticalOnly,
+        Both
+    }
+}