add native_control doc of ScrollViewer

ScrollViewer

doc/source/handycontrol/native_controls/scrollViewer/index.md

@@ -1,5 +1,48 @@
 ---
-title: 建设中
+title: ScrollViewer 滚动视图
 ---
 
-建设中
+# ScrollViewerNativeBaseStyle
+
+滚动视图的基础样式，不推荐直接使用，应该始终被其它样式以BasedOn的方式使用。
+
+案例：
+
+```xml
+<Style BasedOn="{StaticResource ScrollViewerNativeBaseStyle}" TargetType="ScrollViewer"/>
+```
+
+`xaml`中：
+
+```xml
+<ScrollViewer>
+   <Grid Height="500">
+      <TextBlock Text="内容区域"></TextBlock>
+   </Grid>
+</ScrollViewer>
+```
+
+效果：
+
+![ScrollViewer.DefaultStyle](https://raw.githubusercontent.com/HandyOrg/HandyOrgResource/master/HandyControl/Doc/native_controls/ScrollViewer.DefaultStyle.png)
+
+# ScrollViewerUpDown
+
+显示上下按钮的滚动视图样式
+
+案例：
+
+```xml
+<ScrollViewer Style="{DynamicResource ScrollViewerUpDown}">
+    <StackPanel Height="500">
+        <TextBlock Text="内容区域" Height="250"></TextBlock>
+        <TextBlock Text="内容区域" Height="250"></TextBlock>
+        <TextBlock Text="内容区域"></TextBlock>
+        <TextBlock Text="内容区域"></TextBlock>
+    </StackPanel>
+</ScrollViewer>
+```
+
+效果：
+
+![ScrollViewer.UpDownStyle](https://raw.githubusercontent.com/HandyOrg/HandyOrgResource/master/HandyControl/Doc/native_controls/ScrollViewer.UpDownStyle.png)