diff --git a/inc/hgl/platform/compiler/Microsoft.h b/inc/hgl/platform/compiler/Microsoft.h
index 9bf7dc0..01150d8 100644
--- a/inc/hgl/platform/compiler/Microsoft.h
+++ b/inc/hgl/platform/compiler/Microsoft.h
@@ -18,6 +18,12 @@
 
 #define HGL_THREAD_LOCAL_STORAGE        __declspec(thread)                              //线程本地储存
 //--------------------------------------------------------------------------------------------------
+#if _MSVC_LANG>=201704L         //C++20
+using u8char    =char8_t;
+#else
+using u8char    =char;
+#endif
+
 #define HGL_FMT_I64            "%I64d"
 #define HGL_FMT_U64            "%I64u"
 //参考文档最后查阅支持版本为VC2013，网址：http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx
diff --git a/inc/hgl/platform/os/MSWindows.h b/inc/hgl/platform/os/MSWindows.h
index 506fc42..a68bce8 100644
--- a/inc/hgl/platform/os/MSWindows.h
+++ b/inc/hgl/platform/os/MSWindows.h
@@ -11,7 +11,6 @@
 //--------------------------------------------------------------------------------------------------
 using u32char           =char32_t;
 using u16char           =wchar_t;
-using u8char            =char8_t;
 using os_char           =wchar_t;
 
 #define to_oschar       to_u16
diff --git a/src/Other/CodePage.cpp b/src/Other/CodePage.cpp
index b8d9426..16425a0 100644
--- a/src/Other/CodePage.cpp
+++ b/src/Other/CodePage.cpp
@@ -22,9 +22,9 @@ namespace hgl
             return(-1);
 
         const u16char *sp=src;
-        uint8 *tp=(uint8 *)dst;
+        u8char *tp=dst;
 
-        while(*sp&&(int(tp-(uint8 *)dst)<dst_size))
+        while(*sp&&(int(tp-dst)<dst_size))
         {
             if(*sp<=0x7F)                       // U-00000000 - U-0000007F: 0xxx
             {
@@ -47,7 +47,7 @@ namespace hgl
 
 //        *tp=0;
 
-        return int(tp-(uint8 *)dst);
+        return int(tp-dst);
     }
 
     int    u8_to_u16(u16char *dst,int dst_size,const u8char *src,const int src_size)
@@ -63,7 +63,7 @@ namespace hgl
         if(!dst||dst_size<=0)
             return(-1);
 
-        const uint8 *sp=(uint8 *)src;
+        const u8char *sp=src;
         u16char *tp=dst;
 
         while(*sp&&(int(tp-dst)<dst_size))
@@ -174,11 +174,11 @@ namespace hgl
             return(nullptr);
         }
 
-        uint8 *sp=(uint8 *)src;
+        const u8char *sp=src;
 
         dst_size=0;
 
-        while(*sp&&(sp-(uint8 *)src)<src_size)
+        while(*sp&&(sp-src)<src_size)
         {
             if(*sp<0x80)                        //    U-00000000 - U-0000007F: 0xxxxxxx
             {