C#导入和导出CSV文件

一、手工导出导出

1、winform

void DataGridViewToExcel(DataGridView dataGridView1)
{
  SaveFileDialog saveFileDialog = new SaveFileDialog();
  saveFileDialog.Filter = "Execl files (*.xls)|*.xls";
  saveFileDialog.FilterIndex = 0;
  saveFileDialog.RestoreDirectory = true;
  saveFileDialog.CreatePrompt = true;
  saveFileDialog.Title = "保存为Excel文件";
  if (saveFileDialog.ShowDialog() == DialogResult.OK)
  {
      Stream stream = saveFileDialog.OpenFile();
      StreamWriter sw = new StreamWriter(stream, System.Text.Encoding.GetEncoding(-0));

      string columnTitle = "";
      try
      {
          for (int i = 0; i < dataGridView1.ColumnCount; i++)
          {
              if (i > 0)
              {
                  columnTitle += "\t";//或者为逗号
              }
              columnTitle += dataGridView1.Columns[i].HeaderText;//写入列标题
          }
          sw.WriteLine(columnTitle);
          for (int j = 0; j < dataGridView1.Rows.Count; j++)
          {
              string columnValue = "";
              for (int k = 0; k < dataGridView1.Columns.Count; k++)
              {
                  if (k > 0)
                  {
                      columnValue += "\t";
                  }
                  columnValue += dataGridView1.Rows[j].Cells[k].Value.ToString();
              }
              sw.WriteLine(columnValue);
          }
          sw.Close();
          stream.Close();
      }
      finally
      {
          sw.Close();
          stream.Close();
      }
  }
}

2、Web导出

不用存磁盘文件<iframe>导出。

string exportFileName = "Export" + DateTime.Now.ToString("yyyyMMddHHmmss");
System.Web.HttpContext context = System.Web.HttpContext.Current;
StringBuilder sb = new StringBuilder();
sb.Append("FirstName,LastName,PhoneNo.,State,TimeZone,ZipCode\n");
for (int i = 0; i < result.PhoneList.Count; i++)
{
  sb.Append(result.PhoneList[i].FirstName + "," + result.PhoneList[i].LastName + "," + result.PhoneList[i].ZipCode + "\n");
}
StringWriter sw = new StringWriter(sb);//一定要StringWriter/StreamWriter才能直接导出
sw.Close();
context.Response.ClearHeaders();
context.Response.Clear();
context.Response.Charset = "UTF-8";
context.Response.ContentEncoding = System.Text.Encoding.UTF8;
context.Response.HeaderEncoding = System.Text.Encoding.UTF8;
context.Response.ContentType = "text/csv";
context.Response.BinaryWrite(new byte[] { 0xEF, 0xBB, 0xBF });//防止中文乱码
context.Response.Write(sw);
context.Response.AppendHeader("content-disposition", "attachment; filename=" + HttpUtility.UrlEncode("1.csv", System.Text.Encoding.UTF8).Replace("+", "%20"));
sw.Close();
context.Response.Flush();
context.Response.End();

二、利用LumenWorks.Framework.IO.Csv读取CSV文件

需要引用LumenWorks.Framework.IO.dll，读取的时候编码格式要选对，否则会乱码，表头自己设置

• phatcher/CsvReader: Extended version of Sebastian Lorien's fast CSV Reader (github.com)
• NuGet Gallery | LumenWorksCsvReader 4.0.0

static DataTable GetData(Stream stream)
{
  using (stream)
  {
      using (StreamReader input = new StreamReader(stream, Encoding.GetEncoding("shift_jis")))
      {
          using (CsvReader csv = new CsvReader(input, false))
          {
              DataTable dt = new DataTable();
              int columnCount = csv.FieldCount;
              for (int i = 0; i < columnCount; i++)
              {
                  dt.Columns.Add("col" + i.ToString());
              }
              while (csv.ReadNextRecord())
              {
                  DataRow dr = dt.NewRow();
                  for (int i = 0; i < columnCount; i++)
                  {
                      if (!string.IsNullOrWhiteSpace(csv[i]))
                      {
                          dr[i] = csv[i];
                      }
                  }
                  dt.Rows.Add(dr);
              }
              return dt;
          }
      }
  }
}

基本使用场景

using System.IO;
using LumenWorks.Framework.IO.Csv;
void ReadCsv()
{
  // open the file "data.csv" which is a CSV file with headers
  using (CsvReader csv =
         new CsvReader(new StreamReader("data.csv"), true))
  {
      int fieldCount = csv.FieldCount;

      string[] headers = csv.GetFieldHeaders();
      while (csv.ReadNextRecord())
      {
          for (int i = 0; i < fieldCount; i++)
              Console.Write(string.Format("{0} = {1};",
                            headers[i], csv[i]));
          Console.WriteLine();
      }
  }
}

复杂的数据绑定方案（Windows窗体）

using System.IO;
using LumenWorks.Framework.IO.Csv;
void ReadCsv()
{
  // open the file "data.csv" which is a CSV file with headers
  using (CachedCsvReader csv = new
         CachedCsvReader(new StreamReader("data.csv"), true))
  {
      // Field headers will automatically be used as column names
      myDataGrid.DataSource = csv;
  }
}

关于C#导入和导出CSV文件的文章就介绍到这了。希望对大家的学习有所帮助，也希望大家多多支持编程宝库。

 子类与父类的相互转换1.父类不能直接强制转换成子类2.子类可以强制转换成父类，但是在父类中只能取父类的字段与方法因此在一个父类对应多个子类的时候，不知道具体是哪个子类的时候，就可以先声明一个父类的类 ...