日期范围选择器错误:initialDate必须在lastDate或之前

Question

im试图使用我在网上找到的日期范围选择器包，但在初次启动时一直收到这个错误

这是我的代码

onTap: () async {
final List<DateTime> picked = await DateRagePicker.showDatePicker(
context: context,
initialFirstDate: new DateTime.now(),
initialLastDate: (new DateTime.now()).add(new Duration(days: 7)),
firstDate: new DateTime(2015),
lastDate: new DateTime(2020)
);
if (picked != null && picked.length == 2) {
print(picked);
}
print("Tapped on container"); 
}

错误：

Failed assertion: line 1280 pos 10: '!initialLastDate.isAfter(lastDate)': initialDate must be on or before lastDate)

Answer 1

断言说initialLastDate在lastDate之后。这是不可能的。DateTime(2020)在2020年初创建DateTime。在撰写本文时，我们已经远远超过了这个日期。将lastDate更改为initialLastDate之后。

final List<DateTime> picked = await DateRagePicker.showDatePicker(
context: context,
initialFirstDate: new DateTime.now(),
initialLastDate: (new DateTime.now()).add(new Duration(days: 7)),
firstDate: new DateTime(2015),
lastDate: new DateTime(2021)//Cannot be 2020
);