add nativeapis

Signed-off-by: Nzengyawen <zengyawen1@huawei.com>

en/application-dev/reference/native-apis/_region.md

+# Region
+
+
+## Overview
+
+Defines the rectangle (dirty region) where the content is to be updated in the local native window.
+
+**Related Modules:**
+
+[NativeWindow](_native_window.md)
+
+
+## Summary
+
+
+
+### Member Variables
+
+| Name | Description | 
+| -------- | -------- |
+| [rects](#rects) | If **rects** is a null pointer, the buffer size is the same as the size of the dirty region by default. | 
+| [rectNumber](#rectnumber) | If **rectNumber** is **0**, the buffer size is the same as the size of the dirty region by default.  | 
+
+
+## Member Variable Description 
+
+
+### rectNumber
+
+  
+```
+int32_t Region::rectNumber
+```
+**Description**<br>
+If **rectNumber** is **0**, the buffer size is the same as the size of the dirty region by default.
+
+
+### *rects
+
+```
+struct Rect Region::*rects
+```
+
+**Description**<br>
+If **rects** is a null pointer, the buffer size is the same as the size of the dirty region by default.
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