是否有像C 中那樣的flush(stdin)來清除F#中的緩沖區？

目前我正在學習一種新的程式語言，即 F#。現在，我正在做一個關于食品訂購系統的專案。而且，我目前遇到的一個問題是，當我完成所有訂購后，系統會提示“您要繼續購買嗎？”。然后我輸入與條件相關的小y和大Y，但系統立即給我“感謝您購買”并按任意鍵繼續陳述。有沒有人有任何想法來處理這個問題？謝謝謝謝。

open System

let menu()=
        printfn "---------------------------------------"
        printfn "        Food ordering system"
        printfn "---------------------------------------"
        printfn "1. ORDER FOOD "
        printfn "2. ORDER DRINK"   
        Console.Write("Enter your selection : ")


let loop()=
       Console.Write("Do you want to continue pruchase?:")

let choice=Console.ReadLine()
if(choice="y"||choice="Y")then
    menu()

let food()=

printfn "\n1.MCD CHICKEN RM 10 \n2.FILET-O-FISH RM 13 \n3.FRENCH FRIES RM 5 \n4.APPLE PIE RM 4"

Console.Write("\nEnter food code that you want :")
let option=Console.ReadLine()
Console.Write("How many you want :")
let qty=Console.ReadLine()

if(option = "1")then
    let price = 10
    let total = int qty*int price
    Console.Write("\nThe price for {0} set MCD CHICKEN ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
elif(option = "2")then
    let price = 13
    let total = int qty*int price
    Console.Write("\nThe price for {0} set FILET-O-FISH ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
elif(option = "3")then
    let price = 5
    let total = int qty*int price
    Console.Write("\nThe price for {0} FRENCH FRIES ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
elif(option = "4")then
    let price = 4
    let total = int qty*int price
    Console.Write("\nThe price for {0} APPLE PIE ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
else
    printfn "Invalid input"
    menu()

let drink()=

printfn "\n1.ICE BLENDED CHOCOLATE MEDIUM RM 8 \n2.MANGO PEACH RM 11 \n3.PEPSI RM 4 \n4.ICE LEMON TEA RM 4"
Console.Write("\nEnter beverage code that you want :")
let option=Console.ReadLine()
Console.Write("How many you want :")
let qty=Console.ReadLine()

if(option = "1")then
    let price = 8
    let total = int qty*int price
    Console.Write("\nThe price for {0} ICE BLENDED CHOCOLATE MEDIUM ",qty)
    Console.Write("is RM {0} \n",total)

    loop()
elif(option = "2")then
    let price = 11
    let total = int qty*int price
    Console.Write("\nThe price for {0} MANGO PEACH ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
elif(option = "3")then
    let price = 4
    let total = int qty*int price
    Console.Write("\nThe price for {0} PEPSI ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
elif(option = "4")then
    let price = 4
    let total = int qty*int price
    Console.Write("\nThe price for {0} ICE LEMON TEA ",qty)
    Console.Write("is RM {0} \n",total)
    loop()
    Console.Write("\nThank you for your purchase ")
else
    printfn "Invalid input"
    menu()


let main()=

menu()
let selection=Console.ReadLine()
if(selection = "1") then
    food()
else
    drink()

main()

uj5u.com熱心網友回復：

這不是重繪 緩沖區的問題。您正在呼叫menufrom loop，但在繼續之前不等待用戶的輸入。

解決此問題的一種方法是將ReadLine呼叫移入menu，但隨后您將遞回呼叫foodand drinkfrom menu，它已經從loop內部food和呼叫drink。這會創建可能不是您真正想要的嵌套控制流。

相反，我建議重新考慮設計，以便不同級別之間的依賴關系是干凈的。每個函式都應該回傳一個由其呼叫函式使用的值，而不是包含回傳選單的回圈。

uj5u.com熱心網友回復：

老實說，這段代碼在很多方面都過于命令式和非慣用的 F#。

我謙虛地建議您將此代碼發布到https://codereview.stackexchange.com/并在那里獲得代碼審查以從中學習。

標籤：调试 编译器错误 F＃

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