使用DateTime.TryParse（）检查多种日期格式

Question

I'm using a method to validate textboxes.

    public bool ValidateDateTimeTextBoxes(params TextBox[] textBoxes)
    {
        DateTime value = DateTime.Today;
        //string dateFormat = "dd/mm/yyyy";

        foreach (var textBox in textBoxes)
        {
            if (!DateTime.TryParse(textBox.Text, out value))
            {
                return false;
            }
        }

        return true;
    }

I want to check the format too. It requires mm/dd/yyyy , but want it to be dd/mm/yyyy

Answer 1

Try DateTime.TryParseExact

DateTime dt;

DateTime.TryParseExact(textBox.Text, 
                       "dd/MM/yyyy", 
                       CultureInfo.InvariantCulture, 
                       DateTimeStyles.None, 
                       out dt);

If you want to check multiple formats as you updated in your question then you can do using another overload method of TryParseExact which takes format parameter as array of string.

string[] formats = { "dd/MM/yyyy", "MM/dd/yyyy" };
DateTime.TryParseExact(txtBox.Text, 
                       formats, 
                       CultureInfo.InvariantCulture, 
                       DateTimeStyles.None, 
                       out value));

Please take care of format string. As you have mentioned format as dd/mm/yyyy . Here mm represents the minute not the month. Use MM for the month representation.

Answer 2

DateTime.TryParseExact(textBox.Text, "dd/MM/yyyy", null, System.Globalization.DateTimeStyles.None, out outDt))

Answer 3

 public bool ValidateDateTimeTextBoxes(params TextBox[] textBoxes)
    {
        DateTime value = DateTime.Now;
        //string dateFormat = "dd/mm/yyyy";

        foreach (var textBox in textBoxes)
        {
            if (!DateTime.TryParse(textBox.Text,"dd/mm/yyyy",new CultureInfo("en-US"), 
                          DateTimeStyles.None out value))
            {
                return false;
            }
        }

        return true;
    }

Answer 4

Try using TryParseExact

Converts the specified string representation of a date and time to its DateTime equivalent. The format of the string representation must match a specified format exactly. The method returns a value that indicates whether the conversion succeeded.

DateTime.TryParseExact(DateValue, 
                       "dd/mm/yyyy", 
                       CultureInfo.InvariantCulture, 
                       DateTimeStyles.None, 
                       out outDatetime);

Answer 5

Use TryParseExact instead which is also faster. Example:

using System;
using System.Globalization;

class Program
{
    static void Main()
    {
        string dateString = "27/05/2012"; // <-- Valid
        string dtformat = "dd/mm/yyyy";
        DateTime dateTime;
        if (DateTime.TryParseExact(dateString, dtformat, CultureInfo.InvariantCulture,
            DateTimeStyles.None, out dateTime))
        {
           Console.WriteLine(dateTime);
        }
    }
}