Flutter Textfield 捕获美元金额并申请费用

Question

我们有一个 flutter 文本字段，用户可以输入一个 int 形式的金额，我们想要做的是 int 计算出减去费用的金额。可能是我无法弄清楚我做错了什么

TextFormField(
                          controller: _offerAmountController,
                          textInputAction: TextInputAction.next,
                          decoration: const InputDecoration(
                            hintText: '5-9999',
                            prefixIcon: Icon(Icons.attach_money_rounded),
                            // labelText: 'Your Offer',
                          ),
                          keyboardType: TextInputType.number,
                          onChanged: (offerAmount) {
                            
                            double sum = int.parse(offerAmount) * 0.1;
                            _offer = sum as int;
                          }),

Text(formatCurrency.format(_offer),
                                style: Theme.of(context)
                                    .textTheme
                                    .headlineSmall
                                    .copyWith(color: Colors.blue[700]))

final formatCurrency =
    NumberFormat.simpleCurrency(locale: 'en_AU', decimalDigits: 0);

Answer 1

试试这个：

setState(() {
  _offer = sum.toInt();
});

Answer 2

试试这个

setState(() {
  _offer = (sum).round();
});

或这个

setState(() {
  _offer = sum.toInt();
});

如果您需要以下代码，也可以尝试这个

double d = 50.5;

int i = d.toInt(); // i = 50
int i = d.round(); // i = 51
int i = d.ceil();  // i = 51
int i = d.floor(); // i = 50