我有一個變數FutureOr<Duration?>,我假設它可以回傳Future<Duration?>或Duration?,對吧?
我怎樣才能FutureBuilder像普通的未來方法一樣使用它,它將等待Duration?如果它是未來,如果不是,直接使用該Duration?值。
當我嘗試以下操作時:
FutureBuilder<Duration?>(
future: durationFuture,
builder: (BuildContext context, snapshot) {
/* my widgets implementations */
},
),
這拋出這個:
The argument type 'FutureOr<Duration?>?' can't be assigned to the parameter type 'Future<Duration?>?'
該FutureOr型別如何作業以及如何基于它實作 FutureBuider?
uj5u.com熱心網友回復:
嘗試這個:
FutureBuilder<Duration?>(
future: Future.value(durationFuture),
builder: (BuildContext context, snapshot) {
/* my widgets implementations */
},
)
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