商城：增加商城首页

(cherry picked from commit 3802fee661)

src/utils/index.ts

@@ -237,6 +237,19 @@ export const fenToYuan = (price: string | number): number => {
   return formatToFraction(price)
 }
 
+/**
+ * 计算环比
+ *
+ * @param value 当前数值
+ * @param reference 对比数值
+ */
+export const calculateRelativeRate = (value?: number, reference?: number) => {
+  // 防止除0
+  if (!reference) return 0
+
+  return ((100 * ((value || 0) - reference)) / reference).toFixed(0)
+}
+
 export const treeFormatter = (ary: any, val: string, valueField = 'value', nameField = 'label') => {
   let o = ''
   if (ary != null) {