Validating my money | 易学教程

问题

I am having some trouble validating a money input. I have used some pointers from my other questions to write some better code. The following is what I'm using to validate whether or not the input is money.

static void Main(string[] args)
{
    string myTest1 = "$1,234.56";
    string myTest2 = "$1.00";
    string myTest3 = "$1000.01";
    string myTest4 = "$1,234,567.89";

    myIsMaybeMoneyValidator Miimv = new myIsMaybeMoneyValidator();

    bool myResult1 = Miimv.isMaybeMoney(myTest1);
    bool myResult2 = Miimv.isMaybeMoney(myTest2);
    bool myResult3 = Miimv.isMaybeMoney(myTest3);
    bool myResult4 = Miimv.isMaybeMoney(myTest4);
}

public bool isMaybeMoney(object theirMaybeMoney)
{
    string myMaybeMoney = theirMaybeMoney.ToString();

    if (myMaybeMoney.StartsWith("-"))
    {
        myMaybeMoney.Remove(0, 1);
    }

    if (!myMaybeMoney.StartsWith("$"))
    {
        return false;
    }

    myMaybeMoney.Remove(0, 1);

    string[] myMaybeMoneyStringArray = myMaybeMoney.Split('.');

    string myMaybeMoneyDollars = myMaybeMoneyStringArray[0];
    string myMaybeMoneyCents = myMaybeMoneyStringArray[1];

    if (!isDollars(myMaybeMoneyDollars))
    {
        return false;
    }

    if (!isCents(myMaybeMoneyCents))
    {
        return false;
    }

    return true;
}

private bool isDollars(string theirMaybeMoneyDollars)
{
    if (!isNumber(theirMaybeMoneyDollars))
        return false;

    try
    {
        int myMaybeDollars = Convert.ToInt32(theirMaybeMoneyDollars);

        if (myMaybeDollars < 1)
            return false;

        return true;
    }
    catch (Exception)
    {
        return false;
    }

    return true;
}

private bool isCents(string theirMaybeMoneyCents)
{
    if (!isNumber(theirMaybeMoneyCents))
        return false;

    try
    {
        int myMaybeCents = Convert.ToInt32(theirMaybeMoneyCents);

        if (myMaybeCents > 99)
            return false;
        if (myMaybeCents < 1)
            return false;

        return true;
    }
    catch (Exception)
    {
        return false;
    }

    return true;
}

private bool isNumber(object theirMaybeNumber)
{
    return Microsoft.VisualBasic.Information.IsNumeric(theirMaybeNumber);
}

The results are all not money, which is pretty confusing to me.

回答1:

Looks like there is a builtin validation for money in C#.

float num;
bool isValid = float.TryParse(str, 
NumberStyles.Currency,
CultureInfo.GetCultureInfo("en-US"), // cached
out num);

FROM: https://stackoverflow.com/a/617847/290822

回答2:

Try decimal.TryParse(myTest4, NumberStyles.Currency, new CultureInfo("en-US"), out myResult4)

回答3:

Just use:

float value;
bool isMoney= float.TryParse(str, 
    NumberStyles.Currency,
    CultureInfo.GetCultureInfo("en-US"),
    out value);

If you want to know what's wrong with your code, it's probably Microsoft.VisualBasic.Information.IsNumeric(theirMaybeNumber); Not handling the commas.

来源：https://stackoverflow.com/questions/9182858/validating-my-money

标签

validation

numbers

currency