VB.NET PrintDocument构造函数代码示例

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

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private WithEvents printButton As System.Windows.Forms.Button
    Private printFont As Font
    Private streamToPrint As StreamReader

    Public Sub New()
        ' The Windows Forms Designer requires the following call.
        InitializeComponent()
        InitializeForm()
    End Sub

    ' The Click event is raised when the user clicks the Print button.
    Private Sub printButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles printButton.Click
        Try
            streamToPrint = New StreamReader("C:\My Documents\MyFile.txt")
            Try
                printFont = New Font("Arial", 10)
                Dim pd As New PrintDocument()
                AddHandler pd.PrintPage, AddressOf Me.pd_PrintPage
                pd.Print()
            Finally
                streamToPrint.Close()
            End Try
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

    ' The PrintPage event is raised for each page to be printed.
    Private Sub pd_PrintPage(ByVal sender As Object, ByVal ev As PrintPageEventArgs)
        Dim linesPerPage As Single = 0
        Dim yPos As Single = 0
        Dim count As Integer = 0
        Dim leftMargin As Single = ev.MarginBounds.Left
        Dim topMargin As Single = ev.MarginBounds.Top
        Dim line As String = Nothing

        ' Calculate the number of lines per page.
        linesPerPage = ev.MarginBounds.Height / printFont.GetHeight(ev.Graphics)

        ' Print each line of the file.
        While count < linesPerPage
            line = streamToPrint.ReadLine()
            If line Is Nothing Then
                Exit While
            End If
            yPos = topMargin + count * printFont.GetHeight(ev.Graphics)
            ev.Graphics.DrawString(line, printFont, Brushes.Black, leftMargin, yPos, New StringFormat())
            count += 1
        End While

        ' If more lines exist, print another page.
        If (line IsNot Nothing) Then
            ev.HasMorePages = True
        Else
            ev.HasMorePages = False
        End If
    End Sub

    Private Sub InitializeForm()
        Me.components = New System.ComponentModel.Container()
        Me.printButton = New System.Windows.Forms.Button()

        Me.ClientSize = New System.Drawing.Size(504, 381)
        Me.Text = "Print Example"

        printButton.ImageAlign = System.Drawing.ContentAlignment.MiddleLeft
        printButton.Location = New System.Drawing.Point(32, 110)
        printButton.FlatStyle = System.Windows.Forms.FlatStyle.Flat
        printButton.TabIndex = 0
        printButton.Text = "Print the file."
        printButton.Size = New System.Drawing.Size(136, 40)
        AddHandler printButton.Click, AddressOf printButton_Click

        Me.Controls.Add(printButton)
    End Sub


    ' This is the main entry point for the application.    
    Public Shared Sub Main()
        Application.Run(New Form1())
    End Sub

End Class