move num ext padding to widget ext

lib/extension/num_extension.dart

@@ -11,11 +11,6 @@ extension NumExt on num {
   ///获取 EdgeInsets.all
   EdgeInsets get edge => EdgeInsets.all(this.w);
 
-  EdgeInsets pading(double horizontal, [double vertical]) => EdgeInsets.symmetric(
-        horizontal: horizontal,
-        vertical: vertical,
-      );
-
   ///圆角
   BorderRadius get radius => BorderRadius.circular(this.w);
 

lib/extension/widget_extension.dart

@@ -3,4 +3,11 @@ import 'package:flutter/material.dart';
 extension WidgetExt on Widget {
   Widget get expanded => Expanded(child: this);
   Widget get center => Center(child: this);
+  Widget padding(double horizontal, [double vertical]) => Padding(
+        padding: EdgeInsets.symmetric(
+          horizontal: horizontal,
+          vertical: vertical,
+        ),
+        child: this,
+      );
 }