你是想实现你前面那个问题中的查找功能吧？！
改改文件排版格式就没有这种问题了。

private void button2_Click(object sender, System.EventArgs e)
        {
            StreamWriter writer = new StreamWriter(@"c:\Customer.txt",true,Encoding.Default);

//所有信息在一行，，查找时遍历一次文件每行的第一个字段就行了。

//或者你用xml格式的文件保存，查找更方便。。
            writer.Write(this.txtName.Text+"\t");//"\t"是制表符，，分隔符的一种
            writer.Write(this.txtPhone.Text+"\t");
            writer.WriteLine(this.txtAddress.Text);
            writer.Close();



            MessageBox.Show("追加成功","提示");
            this.txtName.Clear();
            this.txtAddress.Clear();
            this.txtPhone.Clear();
            this.txtName.Focus();
        }

[quote]你是想实现你前面那个问题中的查找功能吧？！
改改文件排版格式就没有这种问题了。

private void button2_Click(object sender, System.EventArgs e)
        {
            StreamWriter writer = new StreamWriter(@"c:\Customer.txt",true,Encoding.Default);

//所有信息在一行，，查找时遍历一次文件每行的第一个字段就行了。

//或者你用xml格式的文件保存，查找更方便。。
            writer.Write(this.txtName.Text+"\t");//"\t"是制表符，，分隔符的一种
            writer.Write(this.txtPhone.Text+"\t");
            writer.WriteLine(this.txtAddress.Text);
            writer.Close();



            MessageBox.Show("追加成功","提示");
            this.txtName.Clear();
            this.txtAddress.Clear();
            this.txtPhone.Clear();
            this.txtName.Focus();
        }
[/quote]
其实这道题的Customer.txt是有格式要求的：
电话： 464643131
姓名:  杨可
地址： 河北

就像上面这样，要求必须把姓名放在第二行。这样的话怎么实现？

public ArrayList readTxtFile(string path,string fgf)
        {
            if (!File.Exists(path))
            {
                Console.WriteLine("文件不存在！");
                Console.WriteLine("按回车键退出！");
                Console.ReadLine();
                return null;
            }                
            try
            {
                //读出一行文本，并临时存放在ArrayList中
                StreamReader sr = new StreamReader(path, Encoding.GetEncoding("gb2312"));
                string l;
                ArrayList content = new ArrayList();
                ArrayList row = new ArrayList();
                int i = 0;
                while((l = sr.ReadLine()) != null)
                {
                    l = l.Trim();
                    row.Add(l);
                    if(Math.IEEERemainder((i-2),3)==0)//取余函数，被3整除。
                    {
                        row.TrimToSize();
                        content.Add(row);
                        row.Clear();
                    }
                    i++;
                }
                sr.Close();
                content.TrimToSize();
                return content;
            }
            catch(IOException ex)
            {
                Console.WriteLine("读文件出错！请检查文件是否正确。");
                Console.WriteLine(ex.ToString());
                return null;
            }
        }

我写过一个其他格式文本文件读取的函数。。下面列出来，你可以看看对你有没有用；
//用ArrayList必须加这句；
using System.Collections;
//读文件；
//path 工作目录； fgf 分隔符；
public ArrayList readTxtFile(string path,string fgf)
        {
            if (!File.Exists(path))
            {
                Console.WriteLine("文件不存在！");
                Console.WriteLine("按回车键退出！");
                Console.ReadLine();
                return null;
            }                
            try
            {
                //读出一行文本，并临时存放在ArrayList中
                StreamReader sr = new StreamReader(path, Encoding.GetEncoding("gb2312"));
                string l;
                ArrayList content = new ArrayList();
                while((l = sr.ReadLine()) != null)
                {
                    ArrayList row = new ArrayList();
                    l = l.Trim();
                    int length = l.Length;
                    int i = 0;
                    bool fgf_flag = false;
                    while(i < length)
                    {
                        string x = l[i].ToString();
                        i++;
                        if (x.Equals(fgf))
                        {
                            fgf_flag = true;
                            row.Add(l.Substring(0,i-1));
                            length = length-i+1;
                            i = 0;
                        }    
                    }
                    if (!fgf_flag)
                        row.Add(l);
                    row.TrimToSize();

                    //将多行文本储存在ArrayList中，并返回；
                    content.Add(row);
                }
                sr.Close();
                content.TrimToSize();
                return content;
            }
            catch(IOException ex)
            {
                Console.WriteLine("读文件出错！请检查文件是否正确。");
                Console.WriteLine(ex.ToString());
                return null;
            }
        }

//写文件；
public void writeTxtFile(string path,string fgf,ArrayList a)
        {
            //保存文件已存在
            if (File.Exists(path))
            {
                Console.WriteLine("文件已存在！是否覆盖（O）、追加（A）该文件？退出直接按回车键。");
                string over_flag = Console.ReadLine().ToString().Trim();
                
                //追加到文件末尾
                if (over_flag.Equals("A")||over_flag.Equals("a"))
                {
                    try
                    {
                        StreamWriter sw = new StreamWriter(path,true,Encoding.GetEncoding("gb2312"));
                        IEnumerator cIE = a.GetEnumerator();
                        while (cIE.MoveNext())
                        {
                            ArrayList row =(ArrayList)cIE.Current;

                            //读取文本行中的字符段，并输出文件
                            IEnumerator rIE = row.GetEnumerator();
                            int length = row.Count;
                            int i = 0;
                            while (rIE.MoveNext())
                            {
                                string st = rIE.Current.ToString();
                                if (i==length-1)
                                    sw.Write(st);
                                else
                                    sw.Write(st+fgf);
                                i++;
                            }
                            sw.WriteLine();
                        }
                        sw.Close();
                        Console.WriteLine("写文件完毕，按回车键退出。。。");
                        Console.ReadLine();
                    }
                    catch(IOException ex)
                    {
                        Console.WriteLine(ex.ToString());
                        Console.WriteLine("写文件出错！请检查文件是否正确。按回车键退出。。。");
                        Console.ReadLine();
                    }
                }
            }
            
        }
    }
}
//文件太长，只保留了追加文件这个功能；

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