Question 76554 in Flutter Question posted in
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How to Pass value from first two index value to next index textfieldcontroller same listview? – Flutter

First index value is 10. Second index value is 5

I am expecting the next index value to be 10 * 5 = 50, but I am getting the same value for all the index. Why does this happen?

expecting output

void takeCostingValue(String text, String index) {
    Map < String, int > quantities = {};
    try {
        int number = int.parse(text);
        quantities[index] = number;

        var totalObj = quantities.entries.map((e) {
            return e.value;
        }).toList();

        var result = totalObj[0] * totalObj[1];

        setState(() {
            _costtextController = result as TextEditingController;
        });
    }
}

ListView.builder(
    itemCount: costNameListData.length,
    itemBuilder: (context, index) {
        return TextField(
            controller: _costtextController,
            onChanged: (text) {
                takeCostingValue(
                    text, index);
            },
        ),
    },
),
Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0 
    List<TextEditingController> textEditingControllers = [];
 @override
  void initState() {
    super.initState();
    JsonListData.forEach((dynamic str) {
            var textEditingController = TextEditingController(text: '');
            textEditingControllers.add(textEditingController);
          });
  }

  Widget singleItemList(int index) {
    return Container(
      child: Row(
        children: [
          Expanded(
            flex: 3,
child: Row(
    children: [
Container(
                  alignment: Alignment.centerLeft,
                  width: 68,
                  height: 50,
                  child: Text(
                    '${JsonListData[index]['CostName'] ?? ''} :',
                  ),
          ),
]),
),
TextField(controller:textEditingControllers[index],
          keyboardType:TextInputType.numberWithOptions(decimal: true, signed: false),
           inputFormatters: [FilteringTextInputFormatter.allow(RegExp('^$|^(0|([1-9][0-9]{0,}))(\.[0-9]{0,})?$')),
             ],

onChanged: (text) {                                
takeCostingValue(
 text, '${[index]}');

    },), ], ), ); }

    void takeCostingValue(String text, String i) {
try {
if (i == '0') {
double value1 = double.parse(value);
        final value_2 = textEditingControllers[1].text == ''
            ? 1.0
            : textEditingControllers[1].text;
        double value2 = double.parse('${value_2}');
        final res = ((value1) * (value2));

        setState(() {
          textEditingControllers[2] =
              TextEditingController(text: '${res}');
        });
}else if (i == '1') {

 final value_1 = textEditingControllers[0].text == ''
            ? 1.0
            : textEditingControllers[0].text;
        double value2 = double.parse(value);
        double value1 = double.parse('${value_1}');
                final res = ((value1) * (value2));
        setState(() {
          textEditingControllers[3] =
              TextEditingController(text: '${res}');
        });

}
}on FormatException {}
}

  2. 0

    you should provide different TextEditingController for every TextField in yours
    ListView:_fabricCostTextController, _averageCostTextController and _costtextController. this should be the different instance of TextEditingController.
    in other words, you can not use _costtextController for every TextField.

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