流程控制，前台可以模拟审批

Util.DiagramDesigner/Converters/InvertBoolConverter.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+using System.Windows.Markup;
+
+namespace Util.DiagramDesigner
+{
+    public class InvertBoolConverter : MarkupExtension, IValueConverter
+    {
+
+        /// <summary>
+        /// Returns the value for the target property of this markup extension.
+        /// </summary>
+        /// <param name="serviceProvider">Object that can provide services for the markup extension.</param>
+        /// <returns>Reference to the instance of this Int32IndexToNumberConverter.</returns>
+        public override object ProvideValue(IServiceProvider serviceProvider)
+        {
+            return this;
+        }
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return !(bool)value;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return !(bool)value;
+        }
+    }
+}