C# 方法不断循环

Question

I am struggling to create a program that records the balance of a user. I have constructed four methods that are used to manage the user's method. The methods include Main(), GetAmount(), Withdraw(), and Deposit. Each method performs a specific operation on the data. However, the GetAmount() method continuously loops without returning the amount inputted. I have attempted to use break statements to break out of the loop in the GetAmount() method however it continuously loops the entire method. I would like to check if the input is double. The input should be passed to the method that performs the operation chosen by the user.

 public static void Main() //THIS IS A COPY OF MY CODE
    {
        char transaction;
        Console.WriteLine("Please enter a character 'W' to withdrawl, 'D' to deposit, 'P' to print balance, 'Q' to quit program)");

        while (!char.TryParse(Console.ReadLine(), out transaction) )
        {
            Console.WriteLine("Please enter valid character: ");
        }

        double balance = 0;
        double amount = GetAmount();

        do
        {
            switch (transaction)
            {
                case 'w':
                case 'W':

                    {

                        Withdrawal(amount, ref balance);
                        return;


                    }
                case 'd':
                case 'D':
                    {
                        Deposit(amount, ref balance);
                        return;
                    }
                case 'p':
                case 'P':
                    {
                        Print(balance);
                        return;
                    }
            }
        } while (char.ToUpper(transaction) != 'Q');

        Console.WriteLine("You have typed Q to quit the program!");
        Console.ReadLine();
    }



    public static double GetAmount()
    {
        double amount;
        Console.WriteLine("Please enter amount to withdraw or deposit");
         do
        {
           if (!double.TryParse(Console.ReadLine(), out amount))
            {
                Console.WriteLine("Please enter a valid amount.");
                break;
            }
            if (amount < 0)
            {
                Console.WriteLine("Please enter a value that is > 0.");
                break;
            }

        } while (amount > 0);

        return GetAmount();
    }
    public static void Withdrawal(double amount, ref double balance)
    {
            balance -= amount - 1.5;
        return;
    }

    public static void Deposit(double amount, ref double balance)
    {
        if (amount > 2000)
        {
            balance += amount * 1.01;
        }
        else
        { 
            balance += amount;
        }
        return;
    }
    public static void Print(double balance)
    {
        Console.WriteLine("Your total balance is {0:C}.", balance);
        return;
    }

Answer 1

At the end of the GetAmount() method, say:

return amount;

instead of:

return GetAmount();

The latter is incorrect because it is a recursive method call: https://en.wikipedia.org/wiki/Recursion