委托和等待任务

Question

创建方法委托时，我遇到了一个问题：

D_AmortizationCalsAsync d_AmortizationCalsAsync = AmortizationCalsAsync; // here i have error

public delegate Func<Task<decimal>> D_AmortizationCalsAsync(int amortization, int installmentNumber);

public async Task<decimal> AmortizationCalsAsync(int amortization, int installmentNumber)
    {
      (...)
    }

Tak AmortizationCalsAsync (int，int)返回类型错误

https://learn.microsoft.com/en-us/dotnet/csharp/misc/cs0407?f1url=%3FappId%3Droslyn%26k%3Dk(CS0407)

Answer 1

AmortizationCalsAsync返回一个Task<decimal>，而不是一个Func<Task<decimal>>。如果要将其分配给委托，则需要更改委托的类型：

public delegate Task<decimal> D_AmortizationCalsAsync(int amortization, int installmentNumber);

或者使用匿名lambda创建一个具有正确签名和返回类型的函数(即接受2个整数的函数，并返回不带参数的func和Task<decimal>返回类型)：

D_AmortizationCalsAsync d_AmortizationCalsAsync = 
    (a, i) => () => AmortizationCalsAsync(a, i);