关于打印预览的问题!在线等!
private   void   button1_Click(object   sender,   EventArgs   e) 
                         { 
                                     this..PrinterSettings.PrintFileName   =   @ "d:\a.txt "; 
                                     this.printDocument1.DocumentName   =    "a.txt ";   
                                     this.printPreviewDialog1.Document   =   this.printDocument1; 
                                     printPreviewDialog1.FormBorderStyle   =   FormBorderStyle.Fixed3D; 
                                     this.printPreviewDialog1.ShowDialog(); 
                         } 
 这是我在一个点击按钮中写的代码,当我点击时候,我就想预览文档,但是每次点击后只有一个预览框出来,没有预览的内容.想请教下,为什么啊?是我的printDocument1没设置好吗?
------解决方案--------------------   //在用户按下页面预览按钮时激发的事件 
         private void printPreviewButton_Click(object sender, EventArgs e) { 
             try {   
                 StreamReader streamToPrint = new StreamReader ( "PrintMe.Txt "); 
                 try { 
                     TextFilePrintDocument pd = new TextFilePrintDocument(streamToPrint); //假定为默认打印机   
                     if (storedPageSettings != null) { 
                         pd.DefaultPageSettings = storedPageSettings ; 
                     }   
                     PrintPreviewDialog dlg = new PrintPreviewDialog() ; 
                     dlg.Document = pd; 
                     dlg.ShowDialog();   
                 } finally { 
                     streamToPrint.Close() ; 
                 }   
             } catch(Exception ex) { 
                 MessageBox.Show( "试图预览要打印的文件时发生错误 -  " + ex.Message); 
             }   
         }   
 //------------------------------------------ 
 namespace Microsoft.Samples.WinForms.Cs.PrintingExample5 { 
     using System; 
     using System.ComponentModel; 
     using System.Windows.Forms; 
     using System.Drawing; 
     using System.Drawing.Printing; 
     using System.IO;   
     //  <doc>  
     //  <desc>  
     //     TextFilePrintDocument 将流输出到打印机 
     // 
     //     注意:为了避免在关闭文件时出问题, 
     //     如果发生异常,此类仅使用一个流 
     //     并将它留给调用方,以打开该文件 
     //     进行打印 
     // 
     //  </desc>  
     //  </doc>  
     public class TextFilePrintDocument : PrintDocument { 
         private Font printFont           = null ; 
         private StreamReader streamToPrint = null ;   
         public TextFilePrintDocument(StreamReader streamToPrint) : base ()  { 
             this.streamToPrint = streamToPrint ; 
         }   
         //重写 OnBeginPrint 以设置将要使用的字体 
         protected override void OnBeginPrint(PrintEventArgs ev) { 
             base.OnBeginPrint(ev) ; 
             printFont = new Font( "Arial ", 10); 
         }   
         //重写 OnPrintPage 以为文档提供打印逻辑 
         protected override void OnPrintPage(PrintPageEventArgs ev) {   
             base.OnPrintPage(ev) ;   
             float lpp = 0 ; 
             float yPos =  0 ; 
             int count = 0 ; 
             float leftMargin = ev.MarginBounds.Left; 
             float topMargin = ev.MarginBounds.Top;