fix: 修复水印重复叠加问题

src/hooks/web/useWatermark.ts

@@ -4,8 +4,13 @@ import { addResizeListener, removeResizeListener } from '@/utils/event'
 import { isDef } from '@/utils/is'
 
 const domSymbol = Symbol('watermark-dom')
+const sourceMap = new WeakMap<HTMLElement, {}>()
 
 export function useWatermark(appendEl: Ref<HTMLElement | null> = ref(document.body) as Ref<HTMLElement>) {
+  const appendElRaw = unref(appendEl)
+  if (appendElRaw && sourceMap.has(appendElRaw)) {
+    return sourceMap.get(appendElRaw)
+  }
   const func = useRafThrottle(function () {
     const el = unref(appendEl)
     if (!el) return
@@ -80,6 +85,7 @@ export function useWatermark(appendEl: Ref<HTMLElement | null> = ref(document.bo
     const { clientHeight: height, clientWidth: width } = el
     updateWatermark({ str, width, height })
     el.appendChild(div)
+    sourceMap.set(el, { setWatermark, clear })
     return id
   }