mvc 2 start date and end date validation

问题

Hi guys i'm trying to compare two dates, for some reason the following code will return false, if i specify 25/05/2012 (startdate) and 31/05/12 (end date).

This only happens if 25th is used as the start date, works fine if i use 26th.

 public bool IsValidDate(DateTime startDate, DateTime endDate)
    {
        return startDate < endDate && endDate > startDate;
    }

what could be wrong?

回答1:

You must be mistaken something. For the given input you specified this code returns true:

class Program
{
    static void Main()
    {
        var startDate = new DateTime(2012, 5, 25);
        var endDate = new DateTime(2012, 5, 31);
        Console.WriteLine(IsValidDate(startDate, endDate));
    }

    public static bool IsValidDate(DateTime startDate, DateTime endDate)
    {
        return startDate < endDate && endDate > startDate;
    }
}

Prints true on the console.

Now of course repeating the exact same condition twice is meaningless. Stating the condition once is more than enough:

public bool IsValidDate(DateTime startDate, DateTime endDate)
{
    return startDate < endDate;
}

回答2:

Why would you make a function to check if startDate < endDate?

private void button1_Click(object sender, EventArgs e)
{
    DateTime startDate = new DateTime(2012 , 05 , 25);
    DateTime endDate = new DateTime(2012 , 05 , 31);

    bool rtnval = IsValidDate(startDate, endDate);

}


public bool IsValidDate(DateTime startDate, DateTime endDate)
{
    return startDate < endDate && endDate > startDate; 
}

this code returns true!!!

break it up and check you have the values you want

public bool IsValidDate(DateTime startDate, DateTime endDate)
{
    bool resulta = startDate < endDate; // break here
    bool resultb = endDate > startDate; // break here
    return startDate < endDate && endDate > startDate;
}

// oops i didn't realise its been answered already

来源：https://stackoverflow.com/questions/10750356/mvc-2-start-date-and-end-date-validation

标签

datetime

asp.net-mvc-2