为了开发省力一点-写了通用的textbox类

Imports System.Data
Imports System.Data.SqlClient
Imports System.Windows
Imports System.Windows.Forms
Imports BaseItem.BaseDataOperations
Public Class CommTextBox
    Inherits System.Windows.Forms.TextBox

#Region " 组件设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        ' 该调用是组件设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    'Control 重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    '控件设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是组件设计器所必需的
    ' 可以使用组件设计器修改此过程。不要使用
    ' 代码编辑器修改它。
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        components = New System.ComponentModel.Container
    End Sub

#End Region
#Region "Properties"
    Dim _ConnString As String
    Public Property ConnString() As String
        Get
            Return _ConnString
        End Get
        Set(ByVal Value As String)
            _ConnString = Value
        End Set
    End Property
    Dim _strKey As String = ""
    Public Property strKey() As String
        Get
            Return _strKey
        End Get
        Set(ByVal Value As String)
            _strKey = Value
        End Set
    End Property
    Dim _objRefFrm As Windows.Forms.Form
    Public Property objRefFrm() As Windows.Forms.Form '设置参考窗体
        Get
            Return _objRefFrm
        End Get
        Set(ByVal Value As Windows.Forms.Form)
            _objRefFrm = Value
        End Set
    End Property
    Dim _strTableName As String = ""
    Public Property strTableName() As String
        Get
            Return _strTableName
        End Get
        Set(ByVal Value As String)
            _strTableName = Value
        End Set
    End Property
    Dim _strColumnName As String = ""
    Public Property strColumnName() As String
        Get
            Return _strColumnName
        End Get
        Set(ByVal Value As String)
            _strColumnName = Value
        End Set
    End Property
    Dim _strTargetColumn As String = ""
    Public Property strTargetColumn() As String
        Get
            Return _strTargetColumn
        End Get
        Set(ByVal Value As String)
            _strTargetColumn = Value
        End Set
    End Property
    Dim _blValidate As Boolean = False
    Public Property blValidate() As Boolean
        Get
            Return _blValidate
        End Get
        Set(ByVal Value As Boolean)
            _blValidate = Value
        End Set
    End Property
    Dim _IsValidated As Boolean = False
    Public ReadOnly Property IsValidated() As Boolean
        Get
            Return _IsValidated
        End Get
    End Property
#End Region
    Protected Overrides Sub OnPaint(ByVal pe As System.Windows.Forms.PaintEventArgs)
        MyBase.OnPaint(pe)
        '在此添加自定义绘画代码
    End Sub
    Protected Overrides Sub OnKeyDown(ByVal e As System.Windows.Forms.KeyEventArgs)
        MyBase.OnKeyDown(e)
        If e.KeyCode = Keys.F3 Then
            If Not IsNothing(_objRefFrm) Then
                Dim frm As New Form
                frm = _objRefFrm
                frm.Text = MyBase.Text
                If frm.ShowDialog = DialogResult.OK Then
                    _strKey = frm.Text
                    If _strTargetColumn <> _strColumnName Then
                        MyBase.Text = BaseDataOperation.getValue(_strTableName, _strColumnName, _strKey, _strTargetColumn, _ConnString)
                    Else
                        MyBase.Text = _strKey
                    End If
                    _IsValidated = True
                End If
            End If
        End If
    End Sub
    Protected Overrides Sub OnKeyPress(ByVal e As System.Windows.Forms.KeyPressEventArgs)
        If e.KeyChar = Chr(13) Then
            If MyBase.Text <> _strKey Then
                If MyBase.Text = "" Then
                    _strKey = ""
                Else
                    If IsNothing(_objRefFrm) Then
                        Exit Sub
                    End If
                    If _strTableName = "" Then
                        Exit Sub
                    End If
                    Dim tString As String = MdComm.GetUniqueValue(_strTableName, MyBase.Text, _strColumnName, _strTargetColumn, True)
                    If tString = "" Then
                        Dim frm As New Form
                        frm = _objRefFrm
                        frm.Text = MyBase.Text
                        If frm.ShowDialog = DialogResult.OK Then
                            _strKey = frm.Text
                            If _strTargetColumn <> _strColumnName Then
                                MyBase.Text = BaseDataOperation.getValue(_strTableName, _strColumnName, _strKey, _strTargetColumn, _ConnString)
                            Else
                                MyBase.Text = _strKey
                            End If
                            _IsValidated = True
                        End If
                    Else
                        _strKey = tString
                        If _strTargetColumn <> _strColumnName Then
                            MyBase.Text = BaseDataOperation.getValue(_strTableName, _strColumnName, _strKey, _strTargetColumn, _ConnString)
                        Else
                            MyBase.Text = _strKey
                        End If
                        _IsValidated = True
                    End If
                End If
            End If
        End If
    End Sub
    Protected Overrides Sub OnValidating(ByVal e As System.ComponentModel.CancelEventArgs)
        If _blValidate Then
            If Not _IsValidated Then
                MessageBox.Show("未能确定唯一项", "提示", MessageBoxButtons.OK)
                e.Cancel = True
            End If
        End If
        'If _strKey <> MyBase.Text Then
        'If _blValidate Then
        'MessageBox.Show("未能确定唯一项", "提示", MessageBoxButtons.OK)
        'e.Cancel = True
        'Else
        '    _strKey = ""
        '    'MyBase.Text = ""
        'End If
        'End If
    End Sub

    Protected Overrides Sub OnTextChanged(ByVal e As System.EventArgs)
        If _IsValidated Then
            _IsValidated = False
        End If
    End Sub
End Class