diff --git a/doc/source/handycontrol/extend_controls/popupWindow/index.md b/doc/source/handycontrol/extend_controls/popupWindow/index.md
index ca12ad62..823b0f55 100644
--- a/doc/source/handycontrol/extend_controls/popupWindow/index.md
+++ b/doc/source/handycontrol/extend_controls/popupWindow/index.md
@@ -1,5 +1,34 @@
 ---
-title: 建设中
+title: PopupWindow 弹出窗口
 ---
 
-建设中
\ No newline at end of file
+`PopupWindow` 相对于 `PopTip` 能更灵活地控制弹出元素的位置.
+
+{% note warning %}
+PopupWindow 在未来版本中可能会作废.
+{% endnote %}
+
+```cs
+[TemplatePart(Name = ElementMainBorder, Type = typeof(Border))]
+[TemplatePart(Name = ElementTitleBlock, Type = typeof(TextBlock))]
+public class PopupWindow : System.Windows.Window
+```
+
+# 属性
+
+|属性|描述|默认值|备注|
+|-|-|-|-|
+|PopupElement|弹出元素|||
+|ShowTitle|是否显示标题|true||
+|ShowCancel|是否显示取消按钮|false||
+|ShowBorder|是否显示边框|false|||
+
+# 方法
+
+|名称|说明|
+|-|-|
+| Show(FrameworkElement, bool) | 显示窗口(弹出元素, 是否带有背景) |
+| Show(System.Windows.Window, Point) | 显示窗口(相对窗口, 偏移坐标) |
+| Show(string) | 显示窗口(弹出信息) |
+| ShowDialog(FrameworkElement, bool) | 模态化显示窗口(弹出元素, 是否带有背景) |
+| ShowDialog(string, string title, bool) | 模态化显示窗口(弹出信息, 标题, 是否显示取消按钮) |
\ No newline at end of file
diff --git a/src/Shared/HandyControl_Shared/Controls/Window/PopupWindow.cs b/src/Shared/HandyControl_Shared/Controls/Window/PopupWindow.cs
index dcb20371..b3e3f7bf 100644
--- a/src/Shared/HandyControl_Shared/Controls/Window/PopupWindow.cs
+++ b/src/Shared/HandyControl_Shared/Controls/Window/PopupWindow.cs
@@ -192,7 +192,7 @@ namespace HandyControl.Controls
             window.Show();
         }
 
-        public static bool? ShowDialog(string message, string title = default(string), bool showCancel = false)
+        public static bool? ShowDialog(string message, string title = default, bool showCancel = false)
         {
             var window = new PopupWindow
             {