相关疑难解决方法(0)

我的 Flutter 应用程序的这一部分出现了一个非常讨厌的错误，但不知道为什么：

child: GridView.builder(
    gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 1,
        childAspectRatio: 4 / 3,
        mainAxisSpacing: 30.0,
        crossAxisSpacing: 20.0),
    padding: EdgeInsets.only(left: 20),
    scrollDirection: Axis.horizontal,
    itemCount: products.length,
    itemBuilder: (context, i) => ChangeNotifierProvider.value(
      value: products[i],
      child: Consumer<Product>(
        builder: (context, product, _) {
          return ProductCard(
              product: product,
              onSelected: (prod) {
                setState(() {
                  products.forEach(
                    (item) {
                      item.isSelected = false;
                    },
                  );
                  prod.isSelected = true;
                });
here's the error: SliverGeometry is not valid: The "scrollExtent" is negative.geometry: SliverGeometry(scrollExtent: -10.0, paintExtent: 20.0, maxPaintExtent: -10.0, cacheExtent: 20.0)
scrollExtent: -10.0 …