c#中txt与datagridview的数据交互

参考自：http://blog.csdn.net/polly_yang/article/details/8026149

一. txt中数据显示到datagridview中

    private void button2_Click(object sender, EventArgs e)  
            {  
//新建一个datatable用于保存读入数据 
                DataTable dt = new DataTable();  
                dt.Columns.Add("飞机编号", typeof(string));  
                dt.Columns.Add("到达时间", typeof(string));  
                dt.Columns.Add("剩余油量", typeof(string));  
                dt.Columns.Add("请求类型：起飞/降落", typeof(string));  

//读入文件 
                StreamReader sr = new StreamReader(file_path, Encoding.Default);  
while(!sr.EndOfStream)  
                {  
string[] items = sr.ReadLine().Split(' ');  
                    DataRow dr = dt.NewRow();  
                    dr[0] = items[0];  
                    dr[1] = items[1];  
                    dr[2] = items[2];  
                    dr[3] = items[3];  

                    dt.Rows.Add(dr);  
                }  
//将datatable绑定到datagridview上显示结果 
                dataGridView1.DataSource = dt;  
            }  

二.datagridview保存到txt中

     private void btnExportTxt_Click(object sender, EventArgs e)
        {
            string outFilePath = "";
            SaveFileDialog SaveFileDialog1 = new SaveFileDialog();
            SaveFileDialog1.Title = "导出TXT结果";
            SaveFileDialog1.Filter = "导出TXT结果 (*.txt)|*.txt";
            if (SaveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                string saveFilename = SaveFileDialog1.FileName;
                if (!string.IsNullOrEmpty(saveFilename))
                {
                    outFilePath = SaveFileDialog1.FileName;
                }
            }
            if (outFilePath == "")
            {
                MessageBox.Show("导出路径不存在！");
                return;
            }
            if (dataGridView == null || dataGridView.Rows.Count == 0)
            {
                MessageBox.Show("导出行数不能为空！");
                return;
            }
            FileStream fileStream = new FileStream(outFilePath, FileMode.OpenOrCreate);
            StreamWriter streamWriter = new StreamWriter(fileStream, System.Text.Encoding.Unicode);

            StringBuilder strBuilder = new StringBuilder();

            try
            {
                //添加列名  \t为制表符Tab
                for (int j = 0; j < dataGridView.Columns.Count; j++)
                {
                    strBuilder.Append(dataGridView.Columns[j].Name.ToString() + "\t");
                }
                streamWriter.WriteLine(strBuilder.ToString());
                //添加每行数据
                for (int i = 0; i < dataGridView.Rows.Count; i++)
                {
                    strBuilder = new StringBuilder();
                    for (int j = 0; j < dataGridView.Columns.Count; j++)
                    {
                        strBuilder.Append(dataGridView.Rows[i].Cells[j].Value.ToString() + "\t");
                    }
                    streamWriter.WriteLine(strBuilder.ToString());
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally
            {
                streamWriter.Close();
                fileStream.Close();
                MessageBox.Show("导出完成！");
            }   
        }

3.如果需要导出多个datagridview的数据，可以将
FileStream fileStream = new FileStream(filename, FileMode.OpenOrCreate);
改成：
FileStream fileStream = new FileStream(filename, FileMode.Append);
文件流以追加的形式写进去，这样后面DataGridView的数据也追加进去。