support for .NET framework 3.5

Still have bugs

Net35/HandyControl_Net35/Controls/StepBar/StepBarItem.cs

@@ -0,0 +1,42 @@
+using System.Windows;
+using System.Windows.Controls;
+using HandyControl.Data;
+
+namespace HandyControl.Controls
+{
+    /// <summary>
+    ///     步骤条单元项
+    /// </summary>
+    public class StepBarItem : ContentControl
+    {
+        /// <summary>
+        ///     步骤编号
+        /// </summary>
+        public static readonly DependencyProperty IndexProperty = DependencyProperty.Register(
+            "Index", typeof(int), typeof(StepBarItem), new PropertyMetadata(-1));
+
+        /// <summary>
+        ///     步骤编号
+        /// </summary>
+        public int Index
+        {
+            get => (int) GetValue(IndexProperty);
+            internal set => SetValue(IndexProperty, value);
+        }
+
+        /// <summary>
+        ///     步骤状态
+        /// </summary>
+        public static readonly DependencyProperty StatusProperty = DependencyProperty.Register(
+            "Status", typeof(StepStatus), typeof(StepBarItem), new PropertyMetadata(StepStatus.Waiting));
+
+        /// <summary>
+        ///     步骤状态
+        /// </summary>
+        public StepStatus Status
+        {
+            get => (StepStatus) GetValue(StatusProperty);
+            internal set => SetValue(StatusProperty, value);
+        }
+    }
+}