Public Sub CreateMyPasswordTextBox()
    ' Create an instance of the TextBox control.
    Dim textBox1 As New TextBox()
    ' Set the maximum length of text in the control to eight.
    textBox1.MaxLength = 8
    ' Assign the asterisk to be the password character.
    textBox1.PasswordChar = "*"c
    ' Change all text entered to be lowercase.
    textBox1.CharacterCasing = CharacterCasing.Lower
    ' Align the text in the center of the TextBox control.
    textBox1.TextAlign = HorizontalAlignment.Center
End Sub

' 导入命名空间
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms

public class PasswordFieldByTextBox
   public Shared Sub Main
        Application.Run(New Form1)
   End Sub
End class

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    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

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents TextBox2 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.Button1 = New System.Windows.Forms.Button
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.Label1 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(96, 56)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(104, 104)
        Me.Button1.Name = "Button1"
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "Read Text"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(96, 160)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.TabIndex = 2
        Me.TextBox2.Text = ""
        '
        'Label1
        '
        Me.Label1.Font = New System.Drawing.Font("Microsoft Sans Serif", 24.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label1.Location = New System.Drawing.Point(0, 0)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(184, 40)
        Me.Label1.TabIndex = 3
        Me.Label1.Text = "Passwords"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(292, 273)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox2.Text = TextBox1.Text
    End Sub
End Class