修复一些问题

README.md

@@ -54,7 +54,7 @@ RT-Thread online packages
 
 ## 4、注意事项
 
-无
+如果串口终端不支持中文显示(UTF-8),显示可能会有问题
 
 
 ## 5、联系方式 & 感谢

examples/UrlEncode_Example.c

@@ -21,7 +21,7 @@ int UrlEncode_test(int argc, char* argv[])
     UrlEncode(src, obj, 200);
 
     rt_kprintf("result: %s\n", obj);
-    rt_kprintf("result: %d\n", rt_strlen(obj));
+    rt_kprintf("result length: %d\n", rt_strlen(obj));
  
     return 0;
 }
@@ -48,7 +48,7 @@ int UrlDecode_test(int argc, char* argv[])
     UrlDecode(src, obj, 100);
 
     rt_kprintf("result: %s\n", obj);
-    rt_kprintf("result: %d\n", rt_strlen(obj));
+    rt_kprintf("result length: %d\n", rt_strlen(obj));
  
     return 0;
 }

src/UrlEncode.c

@@ -34,7 +34,7 @@ int UrlEncode(const char *str, char *result, const int max_length)
         {
             if (j + 3 < max_length)
             {
-                sprintf(result + j, "%%%02X", (unsigned char)ch);
+                rt_sprintf(result + j, "%%%02X", (unsigned char)ch);
                 j += 3;
             }
             else