混合使用CloseUp和DropDown事件以及绑定数据可能是解决方案
Imports System.Windows.Forms
Namespace WindowsFormsApplication1
Public Partial Class Form1
Inherits Form
Private isDropedDown As Boolean
Private m_dataSale As DateTime = DateTime.Now
Public Property DataSale() As DateTime
Get
Return m_dataSale
End Get
Set
If isDropedDown Then
If m_dataSale.[Date].AddMonths(1).[Date] = value.[Date] OrElse m_dataSale.[Date].AddMonths(-1).[Date] = value.[Date] OrElse New DateTime(m_dataSale.Year, m_dataSale.Month, 1).AddMonths(1).[Date] = value.[Date] OrElse New DateTime(m_dataSale.Year, m_dataSale.Month, 1).AddMonths(-1).[Date] = value.[Date] Then
MessageBox.Show("Month is changing")
End If
End If
m_dataSale = value
End Set
End Property
Public Sub New()
InitializeComponent()
Dim binding = dateTimePicker1.DataBindings.Add("Value", Me, "DataSale")
binding.DataSourceUpdateMode = DataSourceUpdateMode.OnPropertyChanged
End Sub
Private Sub dateTimePicker1_CloseUp(sender As Object, e As EventArgs)
isDropedDown = False
End Sub
Private Sub dateTimePicker1_DropDown(sender As Object, e As EventArgs)
isDropedDown = True
End Sub
End Class
End Namespace
