C#运用实例.读取csv里面的词条，对每一个词条抓取百度百科相关资料，然后存取到数据库
第一步：首先需要将csv先装换成datatable，这样我们就容易进行对datatable进行遍历：
/// 将CSV文件的数据读取到DataTable中 /// CSV文件路径 /// 返回读取了CSV数据的DataTable public DataTable OpenCSV(string fileName) { DataTable dt = new DataTable(); FileStream fs = new FileStream(fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read); StreamReader sr = new StreamReader(fs, System.Text.Encoding.Default); //记录每次读取的一行记录 string strLine = ""; //记录每行记录中的各字段内容 string[] aryLine; //标示列数 int columnCount = 0; //标示是否是读取的第一行 bool IsFirst = true; //逐行读取CSV中的数据 while ((strLine = sr.ReadLine()) != null) { aryLine = strLine.Split(','); if (IsFirst == true) { IsFirst = false; columnCount = aryLine.Length; //创建列 for (int i = 0; i < columnCount; i++) { DataColumn dc = new DataColumn(aryLine[i]); dt.Columns.Add(dc); } } else { DataRow dr = dt.NewRow(); for (int j = 0; j < columnCount; j++) { dr[j] = aryLine[j]; } dt.Rows.Add(dr); } } sr.Close(); fs.Close(); return dt; }
特别备注：遍历dadatable的几种方式已经将datatable装换成csv文件：
一、将DataTable内容写入到CSV文件 /// /// 将DataTable中的数据保存成CSV文件 /// private void btnSaveCSV_Click(object sender, EventArgs e) { saveFileDialog1.Filter = "CSV文件|*.CSV"; saveFileDialog1.InitialDirectory = "C:\\"; if (saveFileDialog1.ShowDialog() == DialogResult.Cancel) { return; } else { string fileName = saveFileDialog1.FileName; SaveCSV(ds.Tables[0], fileName); } } /// /// 将DataTable中数据写入到CSV文件中 /// /// 提供保存数据的DataTable /// CSV的文件路径 public void SaveCSV(DataTable dt, string fileName) { FileStream fs = new FileStream(fileName, System.IO.FileMode.Create, System.IO.FileAccess.Write); StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.Default); string data = ""; //写出列名称 for (int i = 0; i < dt.Columns.Count; i++) { data += dt.Columns[i].ColumnName.ToString(); if (i < dt.Columns.Count - 1) { data += ","; } } sw.WriteLine(data); //写出各行数据 for (int i = 0; i < dt.Rows.Count; i++) { data = ""; for (int j = 0; j < dt.Columns.Count; j++) { data += dt.Rows[i][j].ToString(); if (j < dt.Columns.Count - 1) { data += ","; } } sw.WriteLine(data); } sw.Close(); fs.Close(); MessageBox.Show("CSV文件保存成功！"); }
遍历datatable的方法2009-09-08 10:02方法一： DataTable dt = dataSet.Tables[0]; for(int i = 0 ; i < dt.Rows.Count ; i++) { string strName = dt.Rows[i]["字段名"].ToString(); } 方法二： foreach(DataRow myRow in myDataSet.Tables["temp"].Rows) { var str = myRow[0].ToString(); } 方法三： foeach(DataRow dr in dt.Rows) { object value = dr["ColumnsName"]; } 方法四： DataTable dt=new DataTable(); foreach(DataRow dr in dt.Rows) { for(int i=0;i<dt.Columns.Count;i++) { dr[i]; } } 方法五 DataRow[] dataRows = null; dataRows = dataTable.Select(fieldParentID + "='" + treeNode.Tag.ToString() + "'", dataTable.DefaultView.Sort); foreach (DataRow dataRow in dataRows) { DataRow dataRow = dataTable.Rows[i]; ?? = dataRow[fieldParentID].ToString(); }
第二步呢： 就是必须用到post方式提交啦，
/// <summary>
/// post数据请求，返回html代码
/// </summary>
/// <param name="areaName">输入百科词条</param>
/// <returns></returns>
public string UrlPost(string areaName)
{
Encoding encoding = Encoding.GetEncoding("UTF-8");
Stream outstream = null;
Stream instream = null;
StreamReader sr = null;
string url = "http://baike.baidu.com/search/word?word=" + areaName;
HttpWebRequest request = null;
HttpWebResponse response = null;
// 准备请求,设置参数
request = WebRequest.Create(url) as HttpWebRequest;
request.Method = "POST";
//request.ContentType = "application/x-www-form-urlencoded";
request.ContentType = "text/xml";//注意了，上面的那种方式不可采用，因为当遇到xml格式的就会报远程服务器错误。500
byte[] data = encoding.GetBytes(url);
request.ContentLength = data.Length;
outstream = request.GetRequestStream();
outstream.Write(data, 0, data.Length);
outstream.Flush();
outstream.Close();
//发送请求并获取相应回应数据
response = request.GetResponse() as HttpWebResponse;
//直到request.GetResponse()程序才开始向目标网页发送Post请求
instream = response.GetResponseStream();
sr = new StreamReader(instream, encoding);
//返回结果网页(html)代码
string content = sr.ReadToEnd();
return content;
}
第三部，就是遍历datatable，然后遍历出每个关键字，以post方式提交到百度百科，返回html，然后用正则表达式进行对数据的筛选
/// <summary> /// 点击按钮执行程序 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void btn_click_Click(object sender, EventArgs e) { DataTable dts = OpenCSV("C:\\Users\\kingtopinfo\\Desktop\\CITYLOCATION.csv"); foreach (DataRow dr in dts.Rows) { string sql = ""; string regstr = ""; string regspit = ""; string Title, Content = ""; int Id = Convert.ToInt32(dr["ID"].ToString()); int CityId = Convert.ToInt32(dr["CITYID"].ToString()); decimal Latitude = Convert.ToDecimal(dr["LATITUDE"]); decimal Longitude = Convert.ToDecimal(dr["LONGITUDE"]); //提交数据给页面并返回html string value = dr["CITYNAME"].ToString(); string html = UrlPost(value); //对数据进行处理。 Regex reg = new Regex(@"<div class=""biItemInner"">(\s|\S)+?(<\/div>\s*?)"); MatchCollection mc = reg.Matches(html); foreach (Match m in mc) { regspit += Regex.Replace(Regex.Replace(m.Value, @"</div[^>]*>", ":"), @"</span[^>]*>", ","); } regstr = Regex.Replace(regspit, @"</?div[^>]*>|</?span[^>]*>|</?a[^>]*>| ", ""); string[] area = Regex.Split(regstr, ":", RegexOptions.IgnoreCase); foreach (string i in area) { string[] areaspit = i.Split(','); if (areaspit.Length==2) { Title = areaspit[0]; Content = areaspit[1]; SqlParameter[] paras = { new SqlParameter("@Id", Id), new SqlParameter("@cityId", CityId), new SqlParameter("@latitude", Latitude), new SqlParameter("@longitude", Longitude), new SqlParameter("@cityName", value), new SqlParameter("@title", Title), new SqlParameter("@content", Content ), }; sql = "INSERT INTO chinaarea(ID,CITYID,LATITUDE,LONGITUDE,CITYNAME,TITLE,CONTENT) VALUES (@Id,@cityId,@latitude,@longitude,@cityName,@title,@content)"; SaveSql(sql,paras); } } } }
第四部分，就是数据库的操作了
const string connString = @"Data Source =.;Database = Area;Integrated Security=True"; /// <summary> /// 存入数据库 /// </summary> /// <param name="str"></param> public void SaveSql(string str,SqlParameter[] para) { SqlConnection conn = new SqlConnection(connString); conn.Open(); string mysql = str; SqlCommand cmd = new SqlCommand(mysql, conn); cmd.Parameters.AddRange(para); cmd.ExecuteNonQuery(); conn.Close(); }
此外，这里对正则表达式进行解释
因为返回的都是这种类型的数据，而我们需要得到的是里面的内容，所以采取正则匹配和替换
<div class="biItem"><div class="biItemInner"><span class="biTitle">中文名称</span><div class="biContent">北京</div></div></div>
<div class="biItem"><div class="biItemInner"><span class="biTitle">外文名称</span><div class="biContent">Beijing</div></div></div>
Regex reg = new Regex(@"<div class=""biItemInner"">(\s|\S)+?(<\/div>\s*?)"); 找出<div class="biItemInner"><div>里的内容
Regex.Replace(Regex.Replace(m.Value, @"</div[^>]*>", ":"), @"</span[^>]*>", ","); 对div和span进行替换和以：分组（便于之后数据处理）
Regex.Replace(regspit, @"</?div[^>]*>|</?span[^>]*>|</?a[^>]*>| ", ""); 将regspit里面  还有a标签进行替换（也就是去掉里面的这些标签）
最终的代码整合：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.IO;
using System.Net;
using System.Text.RegularExpressions;
public partial class csv : System.Web.UI.Page
{
const string connString = @"Data Source =.;Database = Area;Integrated Security=True";
protected void Page_Load(object sender, EventArgs e)
{
}
/// <summary>
/// 点击按钮执行程序
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btn_click_Click(object sender, EventArgs e)
{
DataTable dts = OpenCSV("C:\\Users\\kingtopinfo\\Desktop\\CITYLOCATION.csv");
foreach (DataRow dr in dts.Rows)
{
string sql = "";
string regstr = "";
string regspit = "";
string Title, Content = "";
int Id = Convert.ToInt32(dr["ID"].ToString());
int CityId = Convert.ToInt32(dr["CITYID"].ToString());
decimal Latitude = Convert.ToDecimal(dr["LATITUDE"]);
decimal Longitude = Convert.ToDecimal(dr["LONGITUDE"]);
//提交数据给页面并返回html
string value = dr["CITYNAME"].ToString();
string html = UrlPost(value);
//对数据进行处理。
Regex reg = new Regex(@"<div class=""biItemInner"">(\s|\S)+?(<\/div>\s*?)");
MatchCollection mc = reg.Matches(html);
foreach (Match m in mc)
{
regspit += Regex.Replace(Regex.Replace(m.Value, @"</div[^>]*>", ":"), @"</span[^>]*>", ",");
}
regstr = Regex.Replace(regspit, @"</?div[^>]*>|</?span[^>]*>|</?a[^>]*>| ", "");
string[] area = Regex.Split(regstr, ":", RegexOptions.IgnoreCase);
foreach (string i in area)
{
string[] areaspit = i.Split(',');
if (areaspit.Length==2)
{
Title = areaspit[0];
Content = areaspit[1];
SqlParameter[] paras = {
new SqlParameter("@Id", Id),
new SqlParameter("@cityId", CityId),
new SqlParameter("@latitude", Latitude),
new SqlParameter("@longitude", Longitude),
new SqlParameter("@cityName", value),
new SqlParameter("@title", Title),
new SqlParameter("@content", Content ),
};
sql = "INSERT INTO chinaarea(ID,CITYID,LATITUDE,LONGITUDE,CITYNAME,TITLE,CONTENT) VALUES (@Id,@cityId,@latitude,@longitude,@cityName,@title,@content)";
SaveSql(sql,paras);
}
}
}
}
/// 将CSV文件的数据读取到DataTable中
/// CSV文件路径
/// 返回读取了CSV数据的DataTable
public DataTable OpenCSV(string fileName)
{
DataTable dt = new DataTable();
FileStream fs = new FileStream(fileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
StreamReader sr = new StreamReader(fs, System.Text.Encoding.Default);
//记录每次读取的一行记录
string strLine = "";
//记录每行记录中的各字段内容
string[] aryLine;
//标示列数
int columnCount = 0;
//标示是否是读取的第一行
bool IsFirst = true;
//逐行读取CSV中的数据
while ((strLine = sr.ReadLine()) != null)
{
aryLine = strLine.Split(',');
if (IsFirst == true)
{
IsFirst = false;
columnCount = aryLine.Length;
//创建列
for (