vb.net 验证文本框中的日期
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Validating a date in a textbox
提问by ghost_king
I am trying to valid user input in a textbox which will only takes dates or an empty value (hence the textbox vs a date time picker). Here are the conditions:
我正在尝试在文本框中验证用户输入，该文本框中只需要日期或空值（因此文本框与日期时间选择器）。以下是条件：
- Only a date value ("dd-mm-yyyy" or "dd-mm-yy)
- Must contain only slashes or numbers
- The date has to be on the day it is being typed in
- 只有一个日期值（“dd-mm-yyyy”或“dd-mm-yy”）
- 必须只包含斜杠或数字
- 日期必须是输入日期
This is what I have so far:
这是我到目前为止：
Private Sub tbApp1_TextChanged(sender As System.Object, e As System.EventArgs) Handles tbApp1.TextChanged
If Not Me.tbApp1.Text = String.Empty Then
If Not DateTime.TryParseExact(tbApp1.Text.Trim, formats, New Globalization.CultureInfo("en-US"), Globalization.DateTimeStyles.None, dtTemp) Then
If Not tbApp1.Text.Trim = DateTime.Today.Date Then
ErrorProvider1.SetError(tbApp1, "This is not a valid date; Enter in this format ('M/d/yyyy' or 'M/d/yy')")
End If
Else
ErrorProvider1.Clear()
End If
ElseIf Me.tbApp1.Text.Trim = "" Then
ErrorProvider1.Clear()
End If
End Sub
Masked Textbox use
蒙版文本框使用
'Private Sub mtbApp1_TypeValidationCompleted(ByVal sender As Object, ByVal e As TypeValidationEventArgs) Handles mtbApp1.TypeValidationCompleted
If Not Me.mtbApp1.Text = String.Empty Then
If (Not e.IsValidInput) Then
ErrorProvider1.SetError(mtbApp1, "The data you supplied must be a valid date in the format mm/dd/yyyy.")
Else
' Now that the type has passed basic type validation, enforce more specific type rules.
Dim UserDate As DateTime = CDate(e.ReturnValue)
If (UserDate = DateTime.Now) Then
ErrorProvider1.SetError(mtbApp1, "The data you supplied must be today's date")
e.Cancel = True
End If
End If
ErrorProvider1.Clear()
End If
End Sub'
I noticed for a date like 03/18/2014 when it loaded back into the masked textbox it converts to 31/82/014. How could i fix this? The query pulls back the field as
我注意到像 2014 年 3 月 18 日这样的日期，当它加载回掩码文本框时，它会转换为 31/82/014。我怎么能解决这个问题？查询将字段拉回为
CONVERT(VARCHAR(10),Date,101) AS Date
I set it in vb as :
我在 vb 中设置为：
Dim Approval1 As Date = Nothing
and then
进而
If Not IsDBNull(((WorklistsDS.Tables(0).Rows(0).Item("Approval1")))) Then
Approval1 = ((WorklistsDS.Tables(0).Rows(0).Item("Approval1")))
End If
and then loaded into the masked textbox as:
然后加载到掩码文本框中：
If Approval1 <> Nothing Then
Me.mtbApp1.Text = Approval1
End If
回答by Mych
You could also simplify your validation with
您还可以使用以下方法简化验证
If IsDate(tbApp1.Text) Then
'valid date now just check if date falled within permitted range
Dim CompDate As Date = CDate(tbApp1.Text)
Dim MidDate As Date = *enter your min date here*
Dim MaxDate As Date = *enter your max date here*
If CompDate >= MinDate AndAlso CompDate <= MaxDate Then
'Date is within permitted range
......
Else
'Date outside range
'Display error
End If
Else
'text in tbApp1 is not a date
'Display Error
End If
