当ActionViewer的ActionElement变更时直接更新MarginCorrection_Indentation值

DeedyDesigner/Deedy.Activity/ActionViewer.cs

@@ -584,7 +584,7 @@ namespace Deedy.Activity
                         else this.ClearValue(ElementIconPropertyKey);
                     }
                 }
-
+                this.MarginCorrection_Indentation = new Thickness(newValue.DepthLevel * ActionViewer.IndentRuler, 0, 0, 0);
                 if (newValue.IsLocked)
                 {
                     this.IsDraggable = false;

DeedyDesigner/Deedy.Activity/Selector/ActionTemplateSelector.cs

@@ -33,7 +33,7 @@ namespace Deedy.Activity
         public override DataTemplate SelectTemplate(object item, DependencyObject container)
         {
             this.LoadFromSource();
-
+            //TODO：根据类型与契约选择特定的数据模版
             return base.SelectTemplate(item, container);
         }
     }