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-  Foxtable(狐表)  (http://www.foxtable.com/bbs/index.asp)
--  专家坐堂  (http://www.foxtable.com/bbs/list.asp?boardid=2)
----  ValueChanged  (http://www.foxtable.com/bbs/dispbbs.asp?boardid=2&id=108976)
--  作者：huhu
--  发布时间：2017/11/1 17:43:00
--  ValueChanged
afterload
Dim rkqssj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker1")
Dim rkjzsj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker2")
Dim tjrkzq As WinForm.TextBox = e.Form.Controls("TextBox1")
rkqssj.Value = Date.Today.AddDays(-30)
rkjzsj.Value = Date.Today
Dim t1 As TimeSpan  = rkjzsj.value.AddDays(1) - rkqssj.Value
tjrkzq.text = "入库周期共计:" & t1.days & "天"

DateTimePicker1的ValueChanged代码

Dim rkqssj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker1")

Dim rkjzsj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker2")

Dim tjrkzq As WinForm.TextBox = e.Form.Controls("TextBox1")

Dim t1 As TimeSpan  = rkjzsj.value.AddDays(1) - rkqssj.Value

tjrkzq.text = "入库周期共计:" & t1.days & "天"


可是打开窗口提示

错误所在事件：窗口,仓库明细,DateTimePicker1,ValueChanged

详细错误信息：

未设置对象变量或 With 块变量。
--  作者：有点甜
--  发布时间：2017/11/1 18:01:00
--  

要判断一下值是不是空值

 

Dim rkqssj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker1")

Dim rkjzsj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker2")

Dim tjrkzq As WinForm.TextBox = e.Form.Controls("TextBox1")

 

If rkqssj.Value = Nothing Then
    msgbox("d1为空")
    Return
End If
If rkjzsj.Value = Nothing Then
    msgbox("d2为空")
    Return
End If


Dim t1 As TimeSpan  = rkjzsj.value.AddDays(1) - rkqssj.Value

tjrkzq.text = "入库周期共计:" & t1.days & "天"