从DateTimePicker获取所选值

Question

从DateTimePicker获取所选值

7

我希望从VB的DateTimePicker中获取所选值（如果我只选择了日期，则只需获取所选日期值。）

在此图像中，我已从此DateTimePicker中选择了（蓝色标记）年份值。因此，我只需要这个年份值。

对于TextBox，我可以使用以下方法获取所选值

TextEndTime.SelectedText

有没有获取 DateTimePicker 选中值的语法或方法？

- Mir Shakawat Ali Jibon

@Ahmed Abdelhameed 我尝试向DTP发送DTM_GETDATETIMEPICKERINFO消息。它返回一个DATETIMEPICKERINFO，其中应该包含底层编辑控件的句柄（以尝试发送EM_GETSEL消息）。但是它没有返回它（为空）。然而，复选框和上下按钮（如果有）的位置被返回了。所以，你可以获取控件的屏幕截图...（是的，这很疯狂 :)） - Jimi

@MirJibon，这是一篇旧文章，与您想要实现的内容有些相关：http://www.vbforums.com/showthread.php?573148-RESOLVED-Select-part-of-DateTimePicker-in-code - dj079

1

与NumericUpDown不同，DTP的大部分内部都是内部的，因此您无法轻松地隔离文本控件以获取所选文本。也许可以使用PInvoke来获取文本，但如果我们知道所有这些的目的，可能更容易做其他事情。 DTP的重点是强制选择有效日期。只有年份不是日期，因此可能应该使用其他内容。 - Ňɏssa Pøngjǣrdenlarp

1

我不知道所有这些背后的业务需求。但是看起来最简单的解决方案是捕获控件的图像并进行一些图像识别。我建议寻找一个解决方法（使用另一个控件或找到另一种方式询问用户的选择）。 - Marco Guignard

通常情况下，您不应该依赖于控件的未记录特性。因为无法保证该特性始终保持不变。 - Reza Aghaei

显示剩余11条评论

2个回答

0

大家好，感谢您们提供的关于DateTimePicker控件如何操作的建议。

我在使用DateTimePicker时遇到了选择问题，当前选定的项目值无法发送到文本框中，因为DTP仅在valuechanged事件中工作。我花了4个小时的时间寻找解决方案，并编写了以下代码：

Public MyEventCounter As Integer = 0

Private Sub DTPAcquDt_DropDown(sender As Object, e As EventArgs) Handles DTPAcquDt.DropDown
        RemoveHandler DTPAcquDt.MouseUp, AddressOf dtpacqudt_closeup
End Sub
Private Sub dtpacqudt_closeup(sender As Object, e As EventArgs) Handles DTPAcquDt.CloseUp
        AddHandler DTPAcquDt.MouseUp, AddressOf dtpacqudt_closeup
        'Check the Mouse/Keys event counter
        If MyEventCounter > 0 Then
            TxtDtAcqu.Text = DTPAcquDt.Value
            'RESET The Counter
            MyEventCounter = 0
        End If
End Sub
Private Sub DTPAcquDt_KeyUp(sender As Object, e As KeyEventArgs) Handles DTPAcquDt.KeyUp
        If e.KeyValue = Keys.Left OrElse e.KeyValue = Keys.Right Then
            MyEventCounter = MyEventCounter + 1
        End If
End Sub
Private Sub DTPAcquDt_MouseUp(sender As Object, e As MouseEventArgs) Handles DTPAcquDt.MouseUp
        MyEventCounter = MyEventCounter + 1
End Sub
Private Sub DTPAcquDt_ValueChanged(sender As Object, e As EventArgs) Handles DTPAcquDt.ValueChanged
        TxtDtAcqu.Text = DTPAcquDt.Value
        'RESET The Counter
        MyEventCounter = 0
End Sub

- Mohamed Obaidulla

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可以查看英文原文，
原文链接

- MatSnow · Accepted Answer

作为DateTimePicker控件可以使用箭头键进行操作，您可以使用SendKeys更改当前选定的值。以下示例获取DateTimePicker的当前DateTime值，并在发送↑键后将值与新值进行比较。最后将DateTimePicker重置为原始值。因此，变量currSelected将包含最后一个选择。

Dim currVal As DateTime
Dim newVal As DateTime
Dim valCheck As Boolean
Dim currSelected As Selection = Selection.None

Public Enum Selection
    None = 0
    Year = 1
    Month = 2
    Day = 3
End Enum

Private Sub CheckDTPSelection(dtp As DateTimePicker)
    valCheck = True
    currVal = dtp.Value
    SendKeys.Send("{UP}")
End Sub

Sub RefreshSelection(dtp As DateTimePicker)
    If valCheck Then
        newVal = dtp.Value

        If currVal.Year <> newVal.Year Then
            currSelected = Selection.Year
        ElseIf currVal.Month <> newVal.Month Then
            currSelected = Selection.Month
        ElseIf currVal.Day <> newVal.Day Then
            currSelected = Selection.Day
        End If

        dtp.Value = currVal
        valCheck = False
    End If
End Sub

Private Sub MyDateTimePicker_DropDown(sender As Object, e As EventArgs) Handles MyDateTimePicker.DropDown
    RemoveHandler MyDateTimePicker.MouseUp, AddressOf MyDateTimePicker_MouseUp
End Sub

Private Sub MyDateTimePicker_CloseUp(sender As Object, e As EventArgs) Handles MyDateTimePicker.CloseUp
    AddHandler MyDateTimePicker.MouseUp, AddressOf MyDateTimePicker_MouseUp
    CheckDTPSelection(MyDateTimePicker)
End Sub

Private Sub MyDateTimePicker_KeyUp(sender As Object, e As KeyEventArgs) Handles MyDateTimePicker.KeyUp
    If e.KeyValue = Keys.Left OrElse e.KeyValue = Keys.Right Then
        CheckDTPSelection(MyDateTimePicker)
    End If
End Sub

Private Sub MyDateTimePicker_MouseUp(sender As Object, e As MouseEventArgs) Handles MyDateTimePicker.MouseUp
    CheckDTPSelection(MyDateTimePicker)
End Sub

Private Sub MyDateTimePicker_ValueChanged(sender As Object, e As EventArgs) Handles MyDateTimePicker.ValueChanged
    Dim dtp As DateTimePicker = DirectCast(sender, DateTimePicker)

    RefreshSelection(dtp)
End Sub

Private Sub Btn_WhatsSelected_Click(sender As Object, e As EventArgs) Handles Btn_WhatsSelected.Click
    'Show the current selected value in a MessageBox
    MessageBox.Show(currSelected.ToString())
End Sub