vb.net 如何自动将 datetimepicker 值设置为所选月份的第一天？
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How to set datetimepicker value to 1st of selected month automatically?
提问by Indrah
when i check monthwise radiobtn the datetimepicker value should automatically set to 1st day of selected month.
当我按月检查 radiobtn 时，datetimepicker 值应自动设置为所选月份的第一天。
how to do this??
这该怎么做？？
tried
试过了
dtpDate.value=new Date(1:MM:YYYY)
but not working as expected..
但没有按预期工作..
采纳答案by Nabeel Haxxan
You can try this :
你可以试试这个：
dtpDate.Value = Now.Date.AddDays(-(Now.Day) + 1)
Date.AddDayswill add specified number of days to the date mentioned
Date.AddDays将指定的天数添加到提到的日期
Now.Daywill give the current day
Now.Day将给出当前日期
dtpDate.Value = Now.Date.AddDays(-(Now.Day) + 1)will always points to the first day of current month
dtpDate.Value = Now.Date.AddDays(-(Now.Day) + 1)将始终指向当月的第一天
Updates:set date to 01 of selected month on month change
更新：在月份更改时将日期设置为所选月份的 01
Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DateTimePicker1.ValueChanged
DateTimePicker1.Value = CDate("01/" & DateTimePicker1.Value.Month & "/" & DateTimePicker1.Value.Year)
End Sub
回答by Matt Wilko
Just use the DateTime Constructorto create a new date value using 1 as the day of the month and set the datetime picker to that value:
只需使用DateTime 构造函数创建一个新的日期值，使用 1 作为月份中的第几天，并将日期时间选择器设置为该值：
dtpDate.Value = New DateTime(dtpDate.Value.Year, dtpDate.Value.Month, 1)
回答by Manoj Yadwad
I have found the answer very useful and very easy. I have provided the link below.
我发现答案非常有用且非常简单。我提供了下面的链接。
Getting first and last day of the current month
DateTime now = DateTime.Now;
var startDate = new DateTime(now.Year, now.Month, 1);
var endDate = startDate.AddMonths(1).AddDays(-1);
Originally Posted by Marcin Juraszek (https://stackoverflow.com/users/1163867/marcinjuraszek)
最初由 Marcin Juraszek 发布 ( https://stackoverflow.com/users/1163867/marcinjuraszek)
回答by Nabeel Haxxan
You can change manually date, month and Year of the Selected DateTime in C# by using this I m changing the Selected Date only and set Selected Date 1st Of the selected moth year...
您可以在 C# 中手动更改所选日期时间的日期、月份和年份，方法是使用此我仅更改所选日期并设置所选日期的第 1 个所选月份...
var moodifiedDate = new DateTime(input.Year, input.Month, 1)
