form1.vb

防止重载多个实例的实用源代码(Prevent Multiple Instances of a 32-bit VB Application)（VB or VB.NET）

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

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

    End Sub

    '窗体重写 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

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Label1 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Label1 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(16, 40)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(560, 21)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = "Please input a string ..."
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(16, 16)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(248, 16)
        Me.Label1.TabIndex = 1
        Me.Label1.Text = "Better Auto-Propercase:"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(592, 397)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "Form1"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "Prevent Multiple Instances of a .NET Windows Application"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If UBound(Diagnostics.Process.GetProcessesByName(Diagnostics.Process.GetCurrentProcess.ProcessName)) > 0 Then
            ''Send opening form's TEXT property as a parameter to the function "ActivatePrevInstance"
            ''This works well with an MDI form or a non-MDI form
            ''It is advised that you give a Unique name to your Form so that it doe not conflict with other applications
            'ActivatePrevInstance(Me.Text)
            ActivatePrevInstance("Prevent Multiple Instances of a .NET Windows Application")
        End If
    End Sub

    ''''''''''''''''''''''''''''''''
    'Better Auto-Propercase 
    '''''''''''''''''''''''''''''''
    'VB 6.0 codes:
    ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
    'The "Auto-Propercase Text Box at Entry" tip [VBPJ May 1997, page 63] has a simpler solution. The StrConv 
    'function can propercase any string. You can achieve the same effect with this code in the KeyUp event of
    ' a text box:

    '    Private Sub Text1_KeyUp(ByVal KeyCode As Integer, _
    '    ByVal Shift As Integer)
    '        Dim iCurPos As Integer
    '        iCurPos = Text1.SelStart
    '        Text1.Text = StrConv(Text1, vbProperCase)
    '        Text1.SelStart = iCurPos
    '    End Sub


    Private Sub TextBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp
        Dim iCurPos As Integer

        iCurPos = Me.TextBox1.SelectionStart
        Me.TextBox1.Text = StrConv(Me.TextBox1.Text, VbStrConv.ProperCase)
        Me.TextBox1.SelectionStart = iCurPos
    End Sub
End Class