VB.NET MessageBox.Show方法代码示例

Private Sub DisplayMessageBoxText()

    MessageBox.Show("Hello, world.")
End Sub

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

' Display message box parented to the main form. 
' The Help button opens the Mspaint.chm Help file, 
' and the "mspaint.chm::/paint_brush.htm" Help keyword shows the 
' associated topic.
Dim r8 As DialogResult = MessageBox.Show(Me, "Message with Help file and keyword.", _
                                   "Help Caption", MessageBoxButtons.OK, _
                                   MessageBoxIcon.Question, _
                                   MessageBoxDefaultButton.Button1, 0, _
                                   "mspaint.chm", _
                                   "mspaint.chm::/paint_brush.htm")

' Display a message box. The Help button opens the Mspaint.chm Help file, 
' shows index with the "ovals" keyword selected, and displays the
' associated topic.
Dim r5 As DialogResult = MessageBox.Show("Message with Help file and Help navigator with additional parameter.", _
                                   "Help Caption", MessageBoxButtons.OK, _
                                   MessageBoxIcon.Question, _
                                   MessageBoxDefaultButton.Button1, _
                                   0, "mspaint.chm", _
                                   HelpNavigator.KeywordIndex, "ovals")

' Display a message box parented to the main form. 
' The Help button opens the Mspaint.chm Help file.
Dim r2 As DialogResult = MessageBox.Show(Me, "Message with Help file.", _
                                   "Help Caption", MessageBoxButtons.OK, _
                                   MessageBoxIcon.Question, _
                                   MessageBoxDefaultButton.Button1, _
                                   0, _
                                   "mspaint.chm")

' Display a message box. The Help button opens 
' the Mspaint.chm Help file and shows the Help contents 
' on the Index tab.
Dim r3 As DialogResult = MessageBox.Show("Message with Help file and Help navigator.", _
                                   "Help Caption", MessageBoxButtons.OK, _
                                   MessageBoxIcon.Question, _
                                   MessageBoxDefaultButton.Button1, _
                                   0, "mspaint.chm", _
                                   HelpNavigator.Index)

' Display a message box. The Help button opens the Mspaint.chm Help file, 
' and the "mspaint.chm::/paint_brush.htm" Help keyword shows the 
' associated topic.
Dim r7 As DialogResult = MessageBox.Show("Message with Help file and keyword.", _
                                   "Help Caption", MessageBoxButtons.OK, _
                                   MessageBoxIcon.Question, _
                                   MessageBoxDefaultButton.Button1, 0, _
                                   "mspaint.chm", _
                                   "mspaint.chm::/paint_brush.htm")

Private Sub ValidateUserEntry2()


    ' Checks the value of the text.

    If ServerName.Text.Length = 0 Then

        ' Initializes variables to pass to the MessageBox.Show method.

        Dim Message As String = "You did not enter a server name. Cancel this operation?"
        Dim Caption As String = "No Server Name Specified"
        Dim Buttons As Integer = MessageBoxButtons.YesNo

        Dim Result As DialogResult

        'Displays a MessageBox using the Question icon and specifying the No button as the default.

        Result = MessageBox.Show(Me, Message, Caption, MessageBoxButtons.YesNo, _
            MessageBoxIcon.Question, MessageBoxDefaultButton.Button1, MessageBoxOptions.RightAlign)


        ' Gets the result of the MessageBox display.

        If Result = System.Windows.Forms.DialogResult.Yes Then

            ' Closes the parent form.

            Me.Close()

        End If

    End If

End Sub

' Display a message box with a help button. 
' The Help button opens the Mspaint.chm Help file.
Dim r1 As DialogResult = MessageBox.Show("Message with Help file.", _
                                   "Help Caption", MessageBoxButtons.OK, _
                                   MessageBoxIcon.Question, _
                                   MessageBoxDefaultButton.Button1, _
                                   0, _
                                   "mspaint.chm")

' Display a message box with a Help button. Show a custom Help window
' by handling the HelpRequested event.
Private Function AlertMessageWithCustomHelpWindow() As DialogResult

    ' Handle the HelpRequested event for the following message.
    AddHandler Me.HelpRequested, AddressOf Me.Form1_HelpRequested

    Me.Tag = "Message with Help button."

    ' Show a message box with OK and Help buttons.
    Dim r As DialogResult = MessageBox.Show("Message with Help button.", _
                                          "Help Caption", MessageBoxButtons.OK, _
                                          MessageBoxIcon.Question, _
                                          MessageBoxDefaultButton.Button1, _
                                          0, True)

    ' Remove the HelpRequested event handler to keep the event
    ' from being handled for other message boxes.
    RemoveHandler Me.HelpRequested, AddressOf Me.Form1_HelpRequested

    ' Return the dialog box result.
    Return r
End Function

Private Sub Form1_HelpRequested(ByVal sender As System.Object, ByVal hlpevent As System.Windows.Forms.HelpEventArgs)

    ' Create a custom Help window in response to the HelpRequested event.
    Dim helpForm As Form = New Form

    ' Set up the form position, size, and title caption.
    With helpForm
        .StartPosition = FormStartPosition.Manual
        .Size = New Size(200, 400)
        .DesktopLocation = New Point(Me.DesktopBounds.X + _
                                     Me.Size.Width, Me.DesktopBounds.Top)
        .Text = "Help Form"
    End With

    ' Create a label to contain the Help text.
    Dim helpLabel As Label = New Label

    ' Add the label to the form and set its text.
    helpForm.Controls.Add(helpLabel)
    helpLabel.Dock = DockStyle.Fill

    ' Use the sender parameter to identify the context of the Help request.
    ' The parameter must be cast to the Control type to get the Tag property.
    Dim senderControl As Control = CType(sender, Control)

    helpLabel.Text = "Help information shown in response to user action on the '" & _
                      CStr(senderControl.Tag) & "' message."

    ' Set the Help form to be owned by the main form. This helps
    ' to ensure that the Help form is disposed of.
    Me.AddOwnedForm(helpForm)

    ' Show the custom Help window.
    helpForm.Show()

    ' Indicate that the HelpRequested event is handled.
    hlpevent.Handled = True
End Sub

' Display message box parented to the main form. 
' The Help button opens the Mspaint.chm Help file
' and shows the Help contents on the Index tab.
Dim r4 As DialogResult = MessageBox.Show(Me, _
                                      "Message with Help file and Help navigator.", _
                                      "Help Caption", MessageBoxButtons.OK, _
                                      MessageBoxIcon.Question, _
                                      MessageBoxDefaultButton.Button1, _
                                      0, "mspaint.chm", _
                                      HelpNavigator.Index)

Private Sub ValidateUserEntry4()

    ' Checks the value of the text.

    If ServerName.Text.Length = 0 Then

        ' Initializes variables to pass to the MessageBox.Show method.

        Dim Message As String = "You did not enter a server name. Cancel this operation?"
        Dim Caption As String = "No Server Name Specified"
        Dim Buttons As Integer = MessageBoxButtons.YesNo

        Dim Result As DialogResult

        'Displays a MessageBox using the Question icon and specifying the No button as the default.

        Result = MessageBox.Show(Me, Message, Caption, MessageBoxButtons.YesNo, MessageBoxIcon.Question)

        ' Gets the result of the MessageBox display.

        If Result = System.Windows.Forms.DialogResult.Yes Then

            ' Closes the parent form.

            Me.Close()

        End If

    End If

End Sub

Private Sub ValidateUserEntry3()

    ' Checks the value of the text.

    If ServerName.Text.Length = 0 Then

        ' Initializes variables to pass to the MessageBox.Show method.

        Dim Message As String = "You did not enter a server name. Cancel this operation?"
        Dim Caption As String = "No Server Name Specified"
        Dim Buttons As Integer = MessageBoxButtons.YesNo

        Dim Result As DialogResult

        'Displays a MessageBox using the Question icon and specifying the No button as the default.

        Result = MessageBox.Show(Me, Message, Caption, MessageBoxButtons.YesNo, MessageBoxIcon.Question, _
            MessageBoxDefaultButton.Button1)

        ' Gets the result of the MessageBox display.

        If Result = System.Windows.Forms.DialogResult.Yes Then

            ' Closes the parent form.

            Me.Close()

        End If

    End If
End Sub

Private Sub ValidateUserEntry5()

    ' Checks the value of the text.

    If ServerName.Text.Length = 0 Then

        ' Initializes variables to pass to the MessageBox.Show method.

        Dim Message As String = "You did not enter a server name. Cancel this operation?"
        Dim Caption As String = "No Server Name Specified"
        Dim Buttons As Integer = MessageBoxButtons.YesNo

        Dim Result As DialogResult

        'Displays a MessageBox using the Question icon and specifying the No button as the default.

        Result = MessageBox.Show(Me, Message, Caption, MessageBoxButtons.YesNo)

        ' Gets the result of the MessageBox display.

        If Result = System.Windows.Forms.DialogResult.Yes Then

            ' Closes the parent form.

            Me.Close()

        End If

    End If

End Sub

' Declare ComboBox1.
Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox

' Initialize ComboBox1.
Private Sub InitializeComboBox()
    Me.ComboBox1 = New ComboBox
    Me.ComboBox1.Location = New System.Drawing.Point(128, 48)
    Me.ComboBox1.Name = "ComboBox1"
    Me.ComboBox1.Size = New System.Drawing.Size(100, 21)
    Me.ComboBox1.TabIndex = 0
    Me.ComboBox1.Text = "Typical"
    Dim installs() As String = New String() _
        {"Typical", "Compact", "Custom"}
    ComboBox1.Items.AddRange(installs)
    Me.Controls.Add(Me.ComboBox1)
End Sub

' Handles the ComboBox1 DropDown event. If the user expands the  
' drop-down box, a message box will appear, recommending the
' typical installation.
Private Sub ComboBox1_DropDown _ 
    (ByVal sender As Object, ByVal e As System.EventArgs) _ 
    Handles ComboBox1.DropDown
    MessageBox.Show("Typical installation is strongly recommended.", _
    "Install information", MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub