检查日期是否为真 [英] Checking to see if date is true

问题描述

大家好，检查日期是否是正确的日期时出现了一个小问题，即时检查日期是否不超过31天，并检查"To date"是否大于从日期"这两个功能正常工作，但现在我要检查这些日期是否有效，因此您不能说"2012/10/45"，

我该怎么做，我的日期代码如下所示

Hi all, got a slight problem when checking to see if the date is a proper date, im checking to see if the date is no more than 31 days and also to check if the "To date" is greater than the "From Date" those 2 functions work but now i got to check if those dates are valid so you cant for example say "2012/10/45",

how can i do this my code for the date is as follows

{
        DateTime dt = Convert.ToDateTime(TextBox1.Text);
        DateTime dta = Convert.ToDateTime(TextBox2.Text);
        TimeSpan pp = dta - dt;
        int days = pp.Days;

        string s = TextBox1.Text;
        string t = TextBox2.Text;

        DateTime theDateA = DateTime.Parse(s);
        DateTime theDateB = DateTime.Parse(t);

        if (theDateB > theDateA)
        {
            if (days > 31)
            {
                TextBox1.BackColor = System.Drawing.Color.Red;
                TextBox2.BackColor = System.Drawing.Color.Red;
                date_Error_cell.Text = "Select a DATE NOT more than 31 days";
                date_Error_cell.Attributes.Add("style", "font-weight:bold; text-align:center; font-family:Calibri; color:Red; font-size:large;");
                Monthly_Spend();
                label();
            }
            else
            {

                TextBox1.BackColor = System.Drawing.Color.White;
                TextBox2.BackColor = System.Drawing.Color.White;
                date_Error_cell.Text = "";
                bind_grid();
                Monthly_Spend();
            }
        }
        else
        {
            date_Error_cell.Text = "Select a VALID date";
        }
    }

推荐答案

使用 DateTime.TryParseExact [ ^ ]而不是Parse的方法-它们如果可能的话，进行转换，并返回bool值以指示成功或失败，而不会抛出异常.

Use DateTime.TryParse[^] or DateTime.TryParseExact[^] methods instead of Parse - they do the conversion if they can, and return a bool value to indicate success or failure without throwing exceptions at all.

在您的文本框中，使用正则表达式进行日期检查；

使用以下验证表达式

In your textbox use regular expression for date check;

with the below validation expression

Copy Code(0[1-9]|[12][0-9]|3[01]).(0[1-9]|1[012]).\d{4}

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