打印功能探求之路二
Graphics g = e.Graphics;
float linesPerPage = 0;
float yPosition = 0;
int count = 0;
float leftMargin = e.MarginBounds.Left;
float topMargin = e.MarginBounds.Top;
string line = null;
StringReader lineReader= new StringReader(this.richTextBox1 .Text);
Font printFont = this.richTextBox1.Font;
SolidBrush myBrush = new SolidBrush(Color.Black);
linesPerPage = e.MarginBounds.Height / printFont.GetHeight(g);
while(count < linesPerPage && ((line=lineReader.ReadLine()) != null))
{
yPosition = topMargin + (count * printFont.GetHeight(g));
g.DrawString(line, printFont, myBrush, leftMargin, yPosition, new StringFormat());
count++;
}
if(line != null)
e.HasMorePages = true;
else
e.HasMorePages = false;
把上述代码放到控件 printDocument1 的PrintPage事件中
然后可以利用一个Button的Click 事件中写上
this.PrintDocument.Print()方法来调用它 即可
上述代码功能实现的是读取 控件richTextBox1中的文本内容进行御览打印
其他的就是GUI 编程来限制 颜色等
同理我们可以举一反三 利用上诉代码来读取一个固定文本内容
可以使用下列代码打印一个固定的txt 文档内容（msdn例子http://msdn.microsoft.com/zh-cn/developercenters/ms404294(VS.85).aspx）
前提要把将 PrintPreviewDialog 控件的 Document 属性设置为窗体上的 PrintDocument 组件。
using System;
using System.Drawing;
using System.IO;
using System.Drawing.Printing;
using System.Windows.Forms;
namespace PrintPreviewApp
{
public partial class Form1 : Form
{
private Button printPreviewButton;
private PrintPreviewDialog printPreviewDialog1 = new PrintPreviewDialog();
private PrintDocument printDocument1 = new PrintDocument();
// Declare a string to hold the entire document contents.
private string documentContents;
// Declare a variable to hold the portion of the document that
// is not printed.
private string stringToPrint;
public Form1()
{
this.printPreviewButton = new System.Windows.Forms.Button();
this.printPreviewButton.Location = new System.Drawing.Point(12, 12);
this.printPreviewButton.Size = new System.Drawing.Size(125, 23);
this.printPreviewButton.Text = "Print Preview";
this.printPreviewButton.Click += new System.EventHandler(this.printPreviewButton_Click);
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.printPreviewButton);
printDocument1.PrintPage +=
new PrintPageEventHandler(printDocument1_PrintPage);
}
private void ReadDocument()
{
string docName = "testPage.txt";
string docPath = @"c:/";
printDocument1.DocumentName = docName;
using (FileStream stream = new FileStream(docPath + docName, FileMode.Open))
using (StreamReader reader = new StreamReader(stream))
{
documentContents = reader.ReadToEnd();
}
stringToPrint = documentContents;
}
void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
{
int charactersOnPage = 0;
int linesPerPage = 0;
// Sets the value of charactersOnPage to the number of characters
// of stringToPrint that will fit within the bounds of the page.
e.Graphics.MeasureString(stringToPrint, this.Font,
e.MarginBounds.Size, StringFormat.GenericTypographic,
out charactersOnPage, out linesPerPage);
// Draws the string within the bounds of the page.
e.Graphics.DrawString(stringToPrint, this.Font, Brushes.Black,
e.MarginBounds, StringFormat.GenericTypographic);
// Remove the portion of the string that has been printed.
stringToPrint = stringToPrint.Substring(charactersOnPage);
// Check to see if more pages are to be printed.
e.HasMorePages = (stringToPrint.Length > 0);
// If there are no more pages, reset the string to be printed.
if (!e.HasMorePages)
stringToPrint = documentContents;
}
private void printPreviewButton_Click(object sender, EventArgs e)
{
ReadDocument();
printPreviewDialog1.Document = printDocument1;
printPreviewDialog1.ShowDialog();
}
[STAThread]
static void Main ()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
}
提示：既然我们可以利用上述代码求取某个固定文本的内容 那我们同样可以利用我们学习过的读取本地磁盘或文件代码来实现