特定产品的颤动增量计数器？ [英] Flutter increment counter for a specific product?

问题描述

我正在开发一个包含产品的应用程序，我需要做的是能够增加并获取要存储的增加产品的密钥，目前它们正在全部增加。

I'm doing an application in flutter that contains products, what I need to do is to be able to increase and obtain the key of the increased product to be stored, currently they are increasing all.

我留下图像和代码，谢谢您的帮助

I leave the image and my code, thanks for the help

按下添加图标时，递增两个计数器产品

Widget _buildSearchResults() {
return new ListView.builder(
  itemCount: _productSearchResult.length,
  itemBuilder: (context, i) {
    return new Card(
      child: Column(
        children: <Widget>[
          ExpansionTile(
            leading: new CircleAvatar(
              backgroundImage: new NetworkImage(_productSearchResult[i].image_url),
            ), 
            title: new Text(
              '${_productSearchResult[i].name} \nPrecio: Q${_productSearchResult[i].price} / Medida: ${_productSearchResult[i].unit } ',
            ),
            children: <Widget>[
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: [

                  new Container(
                    child: new IconButton(
                      icon: new Icon(Icons.remove),
                      highlightColor: Colors.green,
                      onPressed: (){
                          _removeProduct();
                      },
                    ),
                  ),
                  new Container(
                    child: new Text('$_counter',
                    style: Theme.of(context).textTheme.display1,),
                  ),
                  new Container( 
                    child: new IconButton(
                      icon: new Icon(Icons.add),
                      highlightColor: Colors.green,
                      onPressed: (){
                          _addProduct();
                      },
                    ),
                  ),
                  new Container( 
                    padding: new EdgeInsets.all(10.0),
                    width: 100.0,
                    child: new RaisedButton(
                      padding: const EdgeInsets.all(8.0),
                      textColor: Colors.white,
                      color: Colors.green,
                      onPressed: _addNumbers,
                      child: new Text("Agregar"),
                    ),
                  ),
                ]
              ),
            ]
          ),
        ],
      )
    );
  },
);

}

_removeProduct() {
setState(() {
  if (_counter > 0) {
    _counter--;
  }
});

}

_addProduct() {
setState(() {
  _counter++;
});

}

推荐答案

您的所有产品都有一个计数器，这就是为什么它对所有产品都显示相同的价值。您需要在_productSearchResult模型中添加计数器，然后在其中增加计数器。而不是显示

You have one counter for all your products which is why it's displaying the same value for all of them. You need to add your counter in your _productSearchResult model and increase it in there. And instead of displaying

Text('$_counter',

您将显示

Text('${_productSearchResult[i].counter}',

，您将更改addProduct方法以采用索引，因此您可以增加每种产品的计数器。

And you'll change your addProduct methods to take in an index so you can increase your counter for each product.

_addProduct(int index) {
setState(() {
  _productSearchResult[index].counter++;
});

和删除产品相同

这篇关于特定产品的颤动增量计数器？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！