Question

我想使用Tuple.Create()创建一个元组签名为Tuple<String,String,Func<String,Control>>

的元组

，但是当我这样做的时候;我收到错误：

The type arguments for method 'Tuple.Create<T1,T2,T3>(T1,T2,T3)' 
cannot be inferred from the usage. Try specifying the types explicitly.

这是我的代码段：

public List<Tuple<String, String, Func<string,Control>>> Headers { get; set; } = new List<Tuple<String, String, Func<string,Control>>> {
            Tuple.Create("Name","Type", TypeControl),
            Tuple.Create("Age","TypeAge", AgeControl),
        };

public Control TypeControl(string data = ""){
 // code returns a Control
}
public Control AgeControl(string data = ""){
 // code returns a Control
}

如果没有Tuple.Create()

，我希望使用new Tuple<T1,T2,T3>(T1,T1,T3)来实现此目的

Answer 1

您必须通过提供类型参数显式指定最后一个参数的类型：

import aioprocessing

async def producer_handler(websocket):
    while True:
        message = await inputqueue.coro_get()
        await websocket.send(message)
        await asyncio.sleep(.1)

inputqueue = aioprocessing.AioQueue()

或传递public List<Tuple<string, string, Func<string, Control>>> Headers { get; set; } = new List<Tuple<string, string, Func<string, Control>>> { Tuple.Create<string, string, Func<string, Control>>("Name","Type", TypeControl), Tuple.Create<string, string, Func<string, Control>>("Age","TypeAge", AgeControl) };：

Func<string, Control>

有关原因的更多信息：

Why can't C# compiler infer generic-type delegate from function signature?

使用多参数Func创建元组

1 个答案: