private void openFileDialogBTN_Click(object sender, System.EventArgs e){
OpenFileDialog openFileDialog=new OpenFileDialog();
openFileDialog.InitialDirectory="c:\\";//注意这里写路径时要用c:\\而不是c:\
openFileDialog.Filter="文本文件|*.*|C#文件|*.cs|所有文件|*.*";
openFileDialog.RestoreDirectory=true;
openFileDialog.FilterIndex=1;
if (openFileDialog.ShowDialog()==DialogResult.OK)
{
fName=openFileDialog.FileName;
File fileOpen=new File(fName);
isFileHaveName=true;
richTextBox1.Text=fileOpen.ReadFile();
richTextBox1.AppendText("");
}
}

private void saveAsDialogBTN_Click(object sender, System.EventArgs e)
{
SaveFileDialog saveFileDialog=new SaveFileDialog();
saveFileDialog.Filter="文本文件|*.*|C#文件|*.cs|所有文件|*.*";
saveFileDialog.FilterIndex=2;
saveFileDialog.RestoreDirectory=true;
if(saveFileDialog.ShowDialog()==DialogResult.OK)
{
if(saveFileDialog.ShowDialog()==DialogResult.OK)
{
fName=saveFileDialog.FileName;
File fSaveAs=new File(fName);
isFileHaveName=true; file://保存的文件有名字
fSaveAs.WriteFile(richTextBox1.Text);
}
}
}

using System;
using System.IO;
using System.Windows.Forms;
using System.Text;

namespace dialog
{
///
/// Summary description for File.
///
public class File
{
string fileName;
public File(string fileName)
{
this.fileName=fileName;
}

public string ReadFile()
{
try
{
StreamReader sr=new StreamReader(fileName,Encoding.Default);
string result=sr.ReadToEnd();
sr.Close();
return result;
}
catch(Exception e){MessageBox.Show(e.Message);}
return null;
}

public void WriteFile(string str)
{
try
{
StreamWriter sw=new StreamWriter(fileName,false,Encoding.Default);
sw.Write(str);
sw.Close();
}
catch(Exception e){MessageBox.Show(e.Message,"保存文件出错！");}
}
}
}

private void fontDialogBTN_Click(object sender, System.EventArgs e)
{
FontDialog fontDialog=new FontDialog();
fontDialog.Color=richTextBox1.ForeColor;
fontDialog.AllowScriptChange=true;
fontDialog.ShowColor=true;
if(fontDialog.ShowDialog()!=DialogResult.Cancel)
{
richTextBox1.SelectionFont=fontDialog.Font;//将当前选定的文字改变字体
}
}

private void colorDialogBTN_Click(object sender, System.EventArgs e)
{
ColorDialog colorDialog=new ColorDialog();
colorDialog.AllowFullOpen=true;
colorDialog.FullOpen=true;
colorDialog.ShowHelp=true;
colorDialog.Color=Color.Black;//初始化当前文本框中的字体颜色，当用户在ColorDialog对话框中点击"取消"按钮
file://恢复原来的值
colorDialog.ShowDialog();
richTextBox1.SelectionColor=colorDialog.Color;
}

private void colorDialogBTN_Click(object sender, System.EventArgs e)
{
ColorDialog colorDialog=new ColorDialog();
colorDialog.AllowFullOpen=true;
colorDialog.FullOpen=true;
colorDialog.ShowHelp=true;
colorDialog.Color=Color.Black;//初始化当前文本框中的字体颜色，当用户在ColorDialog对话框中点击"取消"按钮
file://恢复原来的值
colorDialog.ShowDialog();
richTextBox1.SelectionColor=colorDialog.Color;
}

private void printDocument_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
float linesPerPage=0;//页面的行号
float yPos=0;//打印字符串的纵向位置
int count=0;//行计数器
float leftMargin =e.MarginBounds.Left;//左边距
float topMargin=e.MarginBounds.Top;//上边距
string line=null;//行字符串
Color clr=richTextBox1.SelectionColor;//当前的打印颜色,在我这个程序没有实现不同颜色打印
SolidBrush b =new SolidBrush(clr);//刷子
fnt=richTextBox1.SelectionFont;//当前的打印字体
linesPerPage=e.MarginBounds.Height/fnt.GetHeight(e.Graphics);//每页可打印的行数
file://逐行循行打印一页
while(count<LINESPERPAGE&&((LINE=LINEREADER.READLINE())!=NULL))
{
yPos=topMargin+(count*fnt.GetHeight(e.Graphics));
e.Graphics.DrawString(line,fnt,b,leftMargin,yPos,new StringFormat());
count++;
}
file://如果该页打印完成而line不为空说明还有没完成的页面，发出下一次的打印事件，
file://在下一次的打印中lineReader会自动读取上次没有打印完的内容。lineReader可以记录当前读取的位置
if(line!=null)
e.HasMorePages=true;
else
e.HasMorePages=false;
}

private void printDialogBTN_Click(object sender, System.EventArgs e)
{
PrintDialog printDialog=new PrintDialog();
printDialog.Document=printDocument;
if(printDialog.ShowDialog()!=DialogResult.Cancel)
{
try
{
printDocument.Print();
}
catch(Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}