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首页 - 经验之谈 - 利用[+]按钮和[-]按钮增大和减小日期
发表评论(0)作者:Mike Coleman, 平台:VB6.0+Win98, 阅读:9899, 日期:2000-10-18
Increment and decrement dates with the [+] and [-] keys
By Mike Coleman, Mike.Coleman@anixter.com
If you注释:ve ever used Quicken, you注释:ve probably noticed a handy little feature in that program注释:s date fields. You can press the [+] key to increment one day, [-] to decrement one day, [PgUp] to increment one month, and [PgDn] to decrement one month. In this tip, we注释:ll show you how to emulate this behavior with Visual Basic.

First, insert a text box on a form (txtDate). Set its text property to "" and its Locked property to TRUE.

Now place the following code in the KeyDown event:

Private Sub txtDate_KeyDown(KeyCode As Integer, Shift As Integer)
注释: 107 = "+" KeyPad
注释: 109 = "-" KeyPad
注释: 187 = "+" (Actually this is the "=" key, same as "+" w/o the shift)
注释: 189 = "-"
注释: 33 = PgUp
注释: 34 = PgDn
Dim strYear As String
Dim strMonth As String
Dim strDay As String
If txtDate.Text = "" Then
  txtDate.Text = Format(Now, "m/d/yyyy")
  Exit Sub
End If
strYear = Format(txtDate.Text, "yyyy")
strMonth = Format(txtDate.Text, "mm")
strDay = Format(txtDate.Text, "dd")
Select Case KeyCode
  Case 107, 187 注释: add a day
    txtDate.Text = Format(DateSerial(strYear, strMonth, strDay) + 1, "m/d/yyyy")
  Case 109, 189 注释: sbutract a day
    txtDate.Text = Format(DateSerial(strYear, strMonth, strDay) - 1, "m/d/yyyy")
  Case 33 注释: add a month
    txtDate.Text = Format(DateSerial(strYear, strMonth + 1, strDay), "m/d/yyyy")
  Case 34 注释: subtract a month
    txtDate.Text = Format(DateSerial(strYear, strMonth - 1, strDay), "m/d/yyyy")
End Select
End Sub

The one nasty thing about this is that if you have characters that are not the characters usually in a date (i.e., 1-9, Monday, Tuesday, or /) you get errors in the format command. To overcome this, I set the Locked property to True. This way, the user can注释:t actually type a character in the field, but the KeyDown event still fires.