如何在asp.net中减去两个日期

如何减去两个日期（lblexpyrydate.Text-Label3.Text）

lblexpyrydate.Text=01/05/2013

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Label3.Text=01/04/2011

您可以从一个日期减去另一个日期以获得时间跨度。您不应该尝试对字符串进行日期计算：您的程序可能会在某个地方与假定的日期格式发生冲突

Dim dateFormat As String = "dd/MM/yyyy"
Dim rightNow As DateTime = DateTime.Now

Dim expiryDate As DateTime = rdr.GetDateTime(0)

Dim daysToExpiry As Integer = (expiryDate - rightNow).Days

LblExpirydate.Text = expiryDate.ToString(dateFormat)
Label3.Text = expiryDate.ToString(dateFormat)
LabelExpires.Text = daysToExpiry.ToString & " days"

Dim dateFormat As String = "dd/MM/yyyy"
Dim rightNow As DateTime = DateTime.Now

Dim expiryDate As DateTime = rdr.GetDateTime(0)

Dim daysToExpiry As Integer = (expiryDate - rightNow).Days

LblExpirydate.Text = expiryDate.ToString(dateFormat)
Label3.Text = expiryDate.ToString(dateFormat)
LabelExpires.Text = daysToExpiry.ToString & " days"