如果输入的日期是过去，如何验证文本框以显示错误消息 [英] How Do I Validate A Textbox To Show Error Msg If Date Entered Is In The Past

问题描述

大家好我如何验证文本框以显示错误消息如果输入的日期是过去



i nid这样的东西：

hi guys how do i validate a textbox to show error msg if date entered is in the past

i nid sumthing like this :

string Duedate;
    txtDate.Text = Calendar1.SelectedDate.ToString("yyyy/MM/dd");
    Duedate = txtDate.Text;

        
    date = DateTime.Now;
       
    if (txtDate.Text != "" && Duedate >= date )   
        {
          do some coding for future date here
        }
    else
        {
           lblErrMsg.text =" the entered date is in the past ";
        }

推荐答案

您需要它们作为JavaScript中的日期对象，以便您可以比较它们。



例如：

You need them as date objects in JavaScript so you can compare them.

For example:

var selectedDate = new Date(txtDate.Text);
var date = new Date();

if (selectedDate < date)...

txtDate.Text = Calendar1.SelectedDate.ToString("yyyy/MM/dd");
string Duedate = txtDate.Text;
string date = (DateTime.Now).ToString("yyyy/MM/dd");

if ((txtDate.Text != "") && (Convert.ToDateTime(Duedate) >= Convert.ToDateTime(date)) )
{
do some coding for future date here
}
else
{
lblErrMsg.text =" the entered date is in the past ";
}

您正在尝试将字符串与DateTime对象进行比较。

You're trying to compare a string to a DateTime object.

txtDate.Text = Calendar1.SelectedDate.ToString("yyyy/MM/dd");
if(string.isNullOrwhitespace(txtDate.Text)
{
   lblErrMsg.text =" You must enter a date. ";
} else {

    if (Calendar1.SelectedDate >= DateTime.Now)
    {
        // do some coding for future date here
    }
    else
    {
        lblErrMsg.text =" the entered date is in the past ";
    }
}

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代码未编译，所以我提前为任何拼写问题道歉。

Code not compiled, so I apologize in advance for any spelling issues.

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