为什么只返回一条数据

Question

public string GetTxt(string fileName)
    {
        string line = string.Empty;
        string strSql = "";
        //string[] stringArray;
        try
        {
            using (StreamReader sr = new StreamReader(fileName, Encoding.Default))
            {                while ((line = sr.ReadLine()) != null)
                {
                    string[] stringArray = line.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                    for (int i = 0; i < stringArray.Length; i++)
                    {
                        if (stringArray[0].Length != 16)
                        {
                            continue;
                        }
                        strSql = i + "的值是：" + stringArray[i] + "<br />";
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Response.Write("文件读取错误");
            Response.Write(ex.Message);
        }        return strSql;
    }protected void Page_Load(object sender, EventArgs e)
    {
        
        string fileName = @"D:\BegASPNET\WebSite1\txt\123.dat";
        Response.Write(GetTxt(fileName));
｝为什么只返回一条数据？

Answer 1

strSql = i + "的值是：" + stringArray[i] + "<br />";改strSql &= i + "的值是：" + stringArray[i] + "<br />";

Answer 2

不是很明白你说的一行的意思。瞎回答
看看文件里面内容和 string[] stringArray = line.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries，这语句分割符对吗?    strSql = i + "的值是：" + stringArray[i] + "<br />";
这条语句决定了返回的strSql 里面肯定是最后一行

Answer 3

for (int i = 0; i < stringArray.Length; i++)
                    {
                        if (stringArray[0].Length != 16)
                        {
                            continue;
                        }
                        strSql = i + "的值是：" + stringArray[i] + "<br />";
                    }
虽然这是个循环，但每当执行strSql = i + "的值是：" + stringArray[i] + "<br />";
这句话时候，他就覆盖了上一条记录，应该strSql = i + "的值是：" + stringArray[i] + "<br />";
改成strSql += i + "的值是：" + stringArray[i] + "<br />";
也就是把=改成+=就行了

Answer 4

public string GetTxt(string fileName)
    {
        string line = string.Empty;
        string strSql = "";
        //string[] stringArray;
        try
        {
            using (StreamReader sr = new StreamReader(fileName, Encoding.Default))
            {                while ((line = sr.ReadLine()) != null)
                {
                    string[] stringArray = line.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                    for (int i = 0; i < stringArray.Length; i++)
                    {
                        if (stringArray[0].Length != 16)
                        {
                            continue;
                        }
                        strSql += i + "的值是：" + stringArray[i] + "<br />";
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Response.Write("文件读取错误");
            Response.Write(ex.Message);
        }        return strSql;
    }protected void Page_Load(object sender, EventArgs e)
    {
        
        string fileName = @"D:\BegASPNET\WebSite1\txt\123.dat";
        Response.Write(GetTxt(fileName));
｝

Answer 5

那改用StringBuilder来操作
    using System.Text;
     ...
        public string GetTxt(string fileName)
        {
            string line = string.Empty;
            //string strSql = "";
            StringBuilder sb = new StringBuilder();
            try
            {
                using (StreamReader sr = new StreamReader(fileName, Encoding.Default))
                {                    while ((line = sr.ReadLine()) != null)
                    {
                        string[] stringArray = line.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
                        for (int i = 0; i < stringArray.Length; i++)
                        {
                            if (stringArray[0].Length != 16)
                            {
                                continue;
                            }
                            sb.AppendLine( i + "的值是：" + stringArray[i]);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Response.Write("文件读取错误");
                Response.Write(ex.Message);
            }            return sb.ToString();
        }        protected void Page_Load(object sender, EventArgs e)
        {
            string fileName = @"D:\BegASPNET\WebSite1\txt\123.dat";
            Response.Write(GetTxt(fileName));
        }