VB.net:你怎么知道年初的日期?

编辑

Dim year As New DateTime(DateTime.Now.Year, 1, 1)

Dim year = new DateTime(DateTime.Now.Year, 1, 1)

Dim year As DateTime = new DateTime(DateTime.Now.Year, 1, 1)

Dim d As New Date(2009, 3, 12)

Console.WriteLine(d.DayOfYear) '71
Console.WriteLine(DateDiff(DateInterval.Day, New Date(d.Year, 1, 1), d)) '70

        Dim day1 As DateTime = New DateTime(DateTime.Now.Year, 1, 1)
    Dim ts As TimeSpan
    '
    ts = DateTime.Now - day1
    '
    Label1.Text = ts.Days.ToString
    'or
    Label1.Text = ts.TotalDays.ToString