fix 有默认值情况下，动态处理默认值不触发表单更新问题

 <!--
  * @Date: 2023-03-29 17:44:24
  * @LastEditors: hookehuyr hookehuyr@gmail.com
- * @LastEditTime: 2024-06-17 10:34:10
+ * @LastEditTime: 2024-06-17 10:49:17
  * @FilePath: /data-table/src/components/SignField/MyComponent.vue
  * @Description: 文件描述
 -->
@@ -79,6 +79,8 @@ onMounted(() => {
   // 非只读，有默认值
   if (props.component_props.default) {
     default_value.value = props.component_props.default?.url;
+    image_url.value = props.component_props.default?.url; // 动态处理sign_value值的变化
+    show_control.value = false;
   }
   if (!props.component_props.readonly) {
     show_sign.value = false;