feature：代码初始化。

src/components/SizeSelect/index.vue

@@ -0,0 +1,45 @@
+<template>
+  <div>
+    <el-dropdown trigger="click" @command="handleSetSize">
+      <div class="size-icon--style">
+        <svg-icon class-name="size-icon" icon-class="size" />
+      </div>
+      <template #dropdown>
+        <el-dropdown-menu>
+          <el-dropdown-item v-for="item of sizeOptions" :key="item.value" :disabled="size === item.value" :command="item.value">
+            {{ item.label }}
+          </el-dropdown-item>
+        </el-dropdown-menu>
+      </template>
+    </el-dropdown>
+  </div>
+</template>
+
+<script setup>
+import useAppStore from '@/store/modules/app'
+
+const appStore = useAppStore()
+const size = computed(() => appStore.size)
+const { proxy } = getCurrentInstance()
+const sizeOptions = ref([
+  { label: '大号', value: 'large' },
+  { label: '默认', value: 'default' },
+  { label: '小号', value: 'small' }
+])
+
+function handleSetSize(size) {
+  proxy.$modal.loading('正在切换...')
+  appStore.setSize(size)
+  setTimeout(() => {
+    window.location.reload()
+  }, 1000)
+}
+</script>
+
+<style lang="scss" scoped>
+.size-icon--style {
+  font-size: 18px;
+  line-height: 50px;
+  padding-right: 7px;
+}
+</style>