1、增加LoadingUtils

lib/utils/loading_uitls.dart

+import 'package:flutter_easyloading/flutter_easyloading.dart';
+
+export 'package:flutter_easyloading/flutter_easyloading.dart';
+
+class LoadingUtils {
+  static void showLoading(String str) {
+    EasyLoading.show(status: str, maskType: EasyLoadingMaskType.black);
+  }
+
+  static void dismiss() {
+    EasyLoading.dismiss();
+  }
+}