将数值从文本框更新为db [英] update numeric value from textbox to db
问题描述
我已经坚持了一段时间..
i've been stuck with it for a while..
我的db(sqlite)值设置为double。当我尝试从文本框更新(每个keydown更新数据库)我每次删除一个值时出现一堆错误,文本框是空白的,当我偶然键入一个字符或尝试使用减号" - " ;。
my db (sqlite) value is set to double. when i try to update from a textbox (each keydown updates the db) i get bunch of errors every time i delete a value and the textbox is blank, when i type a charecter by accident or try to use the minus sign "-".
实际上,如果我在输入一个数字后使用它而不是之前使用减号它会起作用..
actually, with the minus sign it works if i use it after entering a number and not before..
我理解db不能接受非数字字符的逻辑,但我不能强迫它只提供数字,减号或保持空白..
i understand the logic that the db cant accept non-numeric characters but i can't force it to reffer only to numbers ,minus sign or keep it blank..
帮助任何人吗?
推荐答案
你好noampro8
Hi noampro8
这样做
Private Sub TextBox_KeyDown(Sender As Object, e As KeyEventArgs) Handles TextBox.KeyDown
Try
If e.KeyCode = Keys.Enter Then
If String.IsNullOrEmpty(Sender.Text) = False AndAlso
Microsoft.VisualBasic.IsNumeric(Sender.Text) Then
'Do Update
e.SuppressKeyPress = True
Else
System.Windows.Forms.SendKeys.Send("{TAB}")
e.SuppressKeyPress = True
End If
End If
Catch ex As Exception
System.Windows.Forms.MessageBox.Show(ex.Message, "Error", System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Error)
End Try
End Sub
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