修改判断assets中文件是否存在的判断方式

lib/services/local_server_service.dart

@@ -163,9 +163,12 @@ class LocalServerService {
     var version = getIt.get<SharedPreferences>().getString(Constant.h5VersionKey) ?? Constant.h5Version;
     var dir = await getApplicationSupportDirectory();
     var distFilePath = '${dir.path}/${Constant.h5DistDir}/$version.zip';
-    if (!await File(distFilePath).exists()) {
+    if (!(await File(distFilePath).exists())) {
       distFilePath = 'assets/$version.zip';
-      if (!await File(distFilePath).exists()) {
+      // 判断 assets 中的文件是否存在？抛出异常代表不存在
+      try {
+        await rootBundle.load(distFilePath);
+      } catch (e) {
         distFilePath = 'assets/dist.zip';
       }
     }