fix loading error

hooks/use-radartile.ts

@@ -86,6 +86,7 @@ export function useRadarTile({
         const cachedBitmap = getFrame(frameIndex)
         if (cachedBitmap) {
             setCurrentBitmap(cachedBitmap)
+            preCacheAroundTime(timestamp)
             setIsLoading(false)
             return cachedBitmap
         }
@@ -108,8 +109,7 @@ export function useRadarTile({
             // 使用高优先级加载当前帧
             loadFrame(url, frameIndex, 'high')
 
-            // 触发预缓存
-            await preCacheAroundTime(timestamp)
+            preCacheAroundTime(timestamp)
 
             return null // 实际的bitmap会通过订阅通知获取
         } catch (err) {
@@ -125,7 +125,7 @@ export function useRadarTile({
     }, [generateUrl, getFrameIndex, getFrame, loadFrame, subscribeToFrame])
 
     // 在指定时间前后预缓存N个帧
-    const preCacheAroundTime = useCallback(async (centerTimestamp: number, timeInterval: number = 360000) => { // 默认5分钟间隔
+    const preCacheAroundTime = useCallback((centerTimestamp: number, timeInterval: number = 360000) => { // 默认5分钟间隔
         if (!generateUrl) return
 
         const urlsWithFrameIndices: Array<{ url: string, frameIndex: number }> = []
@@ -137,6 +137,11 @@ export function useRadarTile({
             const timestamp = centerTimestamp + (i * timeInterval)
             const url = generateUrl(timestamp)
             const frameIndex = getFrameIndex(timestamp)
+
+            if (isFrameCached(frameIndex)) {
+                continue
+            }
+
             urlsWithFrameIndices.push({ url, frameIndex })
         }
 
@@ -165,10 +170,6 @@ export function useRadarTile({
         }
     }, [frameLoaderError, error])
 
-    useEffect(() => {
-        setIsLoading(frameLoaderIsLoading)
-    }, [frameLoaderIsLoading])
-
     // 高级功能：清空缓存
     const clearAllCache = useCallback(() => {
         if (unsubscribeRef.current) {