fix 签名组件只有在data_id存在能查到默认值的时候，只读模式有效果

 <!--
  * @Date: 2023-03-29 17:44:24
  * @LastEditors: hookehuyr hookehuyr@gmail.com
- * @LastEditTime: 2024-06-17 10:52:18
+ * @LastEditTime: 2024-06-17 11:53:25
  * @FilePath: /data-table/src/components/SignField/MyComponent.vue
  * @Description: 文件描述
 -->
@@ -82,7 +82,6 @@ onMounted(() => {
     default_value.value = props.component_props.default?.url; // 默认值显示
     image_url.value = props.component_props.default?.url; // 动态处理sign_value值的变化
     show_control.value = false; // 不显示控制按钮
-  }
     if (!props.component_props.readonly) {
       show_sign.value = false;
       show_control.value = false;
@@ -93,6 +92,12 @@ onMounted(() => {
         esignHeight.value = (window.innerHeight) / 5;
       }, 100);
     }
+  } else {
+    setTimeout(() => {
+      esignWidth.value = wrapperRef?.value?.offsetWidth - 32;
+      esignHeight.value = (window.innerHeight) / 5;
+    }, 100);
+  }
 });
 
 const lineWidth = ref(6);