IP地址输入控件V1.0.1.1版的方法
核心代码:
'只允许输入数字、"." Private Sub txtField_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtField0.KeyPress, txtField1.KeyPress, txtField2.KeyPress, txtField3.KeyPress If e.KeyChar = "." Then Dim tx As TextBox = CType(sender, TextBox) '最后的文本框不可以输入"." '在其它文本框输入"."，相当于输入"Tab"键，即光标到下一文本框 If tx.Text = "" Or tx.SelectedText <> "" Then e.Handled = True End If If tx.Name <> "txtField3" Then SendKeys.Send("{TAB}") Else '最后的文本框不可以输入"." e.Handled = True End If ElseIf (Not IsNumeric(e.KeyChar)) And e.KeyChar <> ControlChars.Back Then e.Handled = True Else Dim tx As TextBox = CType(sender, TextBox) If (Len(tx.Text) = 2 And e.KeyChar <> ControlChars.Back And tx.SelectedText.Length = 0) Then If tx.Name <> "txtField3" Then SendKeys.Send("{TAB}") End If End If End If '控制ControlChars.Back退格键 Dim tx1 As TextBox = CType(sender, TextBox) If (Len(tx1.Text) = 0 And e.KeyChar = ControlChars.Back) Then Select Case tx1.Name Case "txtField3" If txtField3.Text = "" Then txtField2.Focus() End If Case "txtField2" If txtField2.Text = "" Then txtField1.Focus() End If Case "txtField1" If txtField1.Text = "" Then txtField0.Focus() End If End Select End If End Sub
当运行时：
当出现错误时：
