[VB.NET]打印和打印预览功能
打印和打印预览功能
实例说明 在本实例中,我们将制作一个能实现打印和打印预览功能的应用程序。程序运行结果如图60-1所示。 图60-1 运行结果 技术要点 l 打印预览功能的实现 l 打印功能的实现 实现过程 ■ 新建项目 打开Visual Studio.NET,选择"新建项目",在项目类型窗口中选择"Visual Basic项目",在模板窗口中选择"Windows应用程序",在名称域中输入"PrintExample",然后选择保存路径。单击"确认"。 ■ 添加控件和设置属性 向当前窗体上添加三个Button控件,将他们的Text属性改为和界面一致。 ■ 添加组件类和要打印的文件 通过菜单"项目|添加组件"为当前项目添加一个组件类,并添加一个需要打印的文件。 ■ 添加代码 '组件类中的代码 Imports System Imports System.ComponentModel Imports System.Windows.Forms Imports System.Drawing Imports System.Drawing.Printing Imports System.IO Namespace Microsoft.Samples.WinForms.VB.PrintingExample5 Public Class TextFilePrintDocument Inherits PrintDocument Private printFont As Font Private streamToPrint As StreamReader Public Sub New(streamToPrint As StreamReader) MyBase.New Me.streamToPrint = streamToPrint End Sub 'Override OnBeginPrint to set up the font we are going to use Overrides Protected Sub OnBeginPrint(ev As PrintEventArgs) MyBase.OnBeginPrint(ev) printFont = new Font("Arial",10) End Sub 'Override the OnPrintPage to provide the printing logic for the document Overrides Protected Sub OnPrintPage(ev As PrintPageEventArgs) MyBase.OnPrintPage(ev) Dim lpp 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 'Work out the number of lines per page 'Use the MarginBounds on the event to do this lpp = ev.MarginBounds.Height / printFont.GetHeight(ev.Graphics) 'Check count first so that we don't read line that we won't print line=streamToPrint.ReadLine() While ((count < lpp) And Not(line Is Nothing)) yPos = topMargin + (count * printFont.GetHeight(ev.Graphics)) ev.Graphics.DrawString (line,printFont,Brushes.Black,leftMargin,yPos,new StringFormat()) count = count + 1 if (count < lpp) then line=streamToPrint.ReadLine() end if End While If (line <> Nothing) Then ev.HasMorePages = True Else ev.HasMorePages = False End If End Sub End Class End Namespace '主窗体中的代码 Imports System Imports System.ComponentModel Imports System.Windows.Forms Imports System.Drawing Imports System.Drawing.Printing Imports System.IO Namespace Microsoft.Samples.WinForms.VB.PrintingExample5 Public Class PrintForm Inherits System.Windows.Forms.Form Private storedPageSettings As PageSettings Public Sub New () MyBase.New PrintForm = Me InitializeComponent() AddHandler printButton.Click,AddressOf printButton_Click AddHandler pageSetupButton.Click,AddressOf pageSetupButton_Click AddHandler printPreviewButton.Click,AddressOf printPreviewButton_Click End Sub '页面设置 Private Sub pageSetupButton_Click(sender As object,e As System.EventArgs) Try Dim psDlg As New PageSetupDialog If (storedPageSettings Is Nothing) Then storedPageSettings = new PageSettings() End If psDlg.PageSettings = storedPageSettings psDlg.ShowDialog Catch ex As Exception MessageBox.Show("An error occurred - " + ex.Message) End Try End Sub '开始打印 Private Sub printButton_Click(sender As object,e As System.EventArgs) Try Dim streamToPrint As StreamReader = new StreamReader ("PrintMe.Txt") Try '使用缺省打印机 Dim pd As TextFilePrintDocument = new TextFilePrintDocument(streamToPrint) If Not (storedPageSettings Is Nothing) Then pd.DefaultPageSettings = storedPageSettings End If Dim dlg As New PrintDialog() dlg.Document = pd Dim result As DialogResult = dlg.ShowDialog() If (result = System.Windows.Forms.DialogResult.OK) Then pd.Print() End If Finally streamToPrint.Close() End Try Catch ex As Exception MessageBox.Show("An error occurred printing the file - " + ex.Message) End Try End Sub '打印预览 Private Sub printPreviewButton_Click(sender As object,e As System.EventArgs) Try Dim streamToPrint As StreamReader = new StreamReader ("PrintMe.Txt") Try Dim pd As TextFilePrintDocument = new TextFilePrintDocument(streamToPrint) If Not (storedPageSettings Is Nothing) Then pd.DefaultPageSettings = storedPageSettings End If Dim dlg As New PrintPreviewDialog() dlg.Document = pd dlg.ShowDialog() Finally streamToPrint.Close() End Try Catch ex As Exception MessageBox.Show("An error occurred - " + ex.Message) End Try End Sub Public Overloads Overrides Sub Dispose() MyBase.Dispose() components.Dispose() End Sub <STAThread()> Shared Sub Main() System.Windows.Forms.Application.Run(New PrintForm()) End Sub End Class End Namespace ■ 运行程序 单击菜单"调试|启动"或单击 图标运行程序。 小结 在打印和打印预览时,我们可以使用PrintPreviewDialog,PrintPreviewControl控件和PrintDocument控件来实现。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |