1、添加骨架图工具类

2、添加sliver delegate工具类

lib/models/base/widget_model.dart

@@ -45,7 +45,7 @@ class WidgetModel {
       this.isGlobal});
 
   WidgetModel.fromJson(Map<String, dynamic> json) {
-    modId = json['mod_id'];
+    modId = json['mod_id'] is int ? json['mod_id'] as int : int.parse(json['mod_id']?.toString());
     modPid = json['mod_pid'];
     modName = json['mod_name'];
     position = json['position'];

lib/util/custom_sliver_persistent_header_delegate.dart

@@ -0,0 +1,32 @@
+// 自定义 SliverPersistentHeaderDelegate
+import 'package:flutter/material.dart';
+
+class CustomSliverPersistentHeaderDelegate extends SliverPersistentHeaderDelegate {
+  final double max; // 最大高度
+  final double min; // 最小高度
+  final Widget child; // 需要展示的内容
+
+  CustomSliverPersistentHeaderDelegate({@required this.max, @required this.min, @required this.child})
+      // 如果 assert 内部条件不成立，会报错
+      : assert(max != null),
+        assert(min != null),
+        assert(child != null),
+        assert(min <= max),
+        super();
+
+  // 返回展示的内容，如果内容固定可以直接在这定义，如果需要可扩展，这边通过传入值来定义
+  @override
+  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent) => child;
+
+  @override
+  double get maxExtent => max; // 返回最大高度
+
+  @override
+  double get minExtent => min; // 返回最小高度
+
+  @override
+  bool shouldRebuild(CustomSliverPersistentHeaderDelegate oldDelegate) {
+    // 是否需要更新，这里我们定义当高度范围和展示内容被替换的时候进行刷新界面
+    return max != oldDelegate.max || min != oldDelegate.min || child != oldDelegate.child;
+  }
+}

lib/util/shimmer_util.dart

@@ -0,0 +1,16 @@
+import 'package:flutter/material.dart';
+import 'package:shimmer/shimmer.dart';
+
+class ShimmerUtil {
+  static Widget getShimmerWidget({double width, double height, double radius = 0}) {
+    return Shimmer.fromColors(
+      baseColor: Colors.grey[300],
+      highlightColor: Colors.grey[100],
+      child: Container(
+        width: width,
+        height: height,
+        decoration: BoxDecoration(color: Colors.white, borderRadius: BorderRadius.circular(radius)),
+      ),
+    );
+  }
+}

lib/util/sliver_tab_bar_delegate.dart

@@ -0,0 +1,23 @@
+import 'package:flutter/material.dart';
+
+class SliverTabBarDelegate extends SliverPersistentHeaderDelegate {
+  final TabBar widget;
+
+  const SliverTabBarDelegate(this.widget) : assert(widget != null);
+
+  @override
+  Widget build(BuildContext context, double shrinkOffset, bool overlapsContent) {
+    return this.widget;
+  }
+
+  @override
+  bool shouldRebuild(SliverTabBarDelegate oldDelegate) {
+    return false;
+  }
+
+  @override
+  double get maxExtent => widget.preferredSize.height;
+
+  @override
+  double get minExtent => widget.preferredSize.height;
+}