该程序实现数据导入、添加、修改、删除。
并显示信息明细，具体包括：学号、姓名、出生日期、性别、电话、邮箱、家庭住址及学生照片信息等。
功能界面如图所示：

程序如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;using System.IO;namespace StudentManage
{public partial class frmMain : Form{private string fileName = string.Empty;     //定义变量保存读取文件路径的变量  （全局变量）， 默认情况下加载时是空的，等同于 = “”；private string photoName = string.Empty;  //记录上传图片时候的文件路径；private List<string> objListStudent = new  List<string>(); //定义List存储读取到的学生信息；private List<string> objListQuery = new List<string>(); //经过查询满足条件的学生信息；private int actionFlag = 0;  //通过actionFlag值判断是添加还是修改，cationFlag=1(添加)， cationFlag=2(修改)；public frmMain(){InitializeComponent();//禁用明细区域，仅显示明细，而不能手动修改；gboxStudentDetail.Enabled = false;}//运行过程--业务逻辑；//数据的导入和展示：选择文件-》导入到DataGridView中-->展示选择学生明细-->选择学生不同，明细随之变化；/*图片： 选择图片-->通过“选择按钮”保存图片-》通过“提交”将图片另存到一个统一的相对路径；读取图片--》选择一个学员的时候，按照存储的路径展示相应的图片；*///流程：点击关闭--》询问是否保存数据，如果需要，保存，不需要直接退出；// 关于保存：添加---》添加的放到最后；  修改：如何定位到修改的学生信息？？？、//换个思维： objListStudent包含了所有数据，在保存前将现有文件清空，把objListStudent数据写入到文件；//控件事件；private void button1_Click(object sender, EventArgs e)  //导入数据并显示；{//【1】选择文件OpenFileDialog openfile = new OpenFileDialog();openfile.Filter = "CSV文件(*.csv)|*.csv|TXT文件(*.txt)|*.txt|所有文件(*.*)|*.*";    //文件类型；if (openfile.ShowDialog() == DialogResult.OK)   //选择打开按钮{fileName = openfile.FileName;   //将选择的文件名完整路径赋给全局变量fileName；}//【2】把文件的数据读取到List中；//为防止读取的时候有些文件无法正常读取,如文件已被删除，正在处理等，加一个异常处理；try{//读取文件；objListStudent = ReadFileToList(fileName);}catch (Exception ex){MessageBox.Show("读取文件出现错误，具体错误如下：" + ex.Message, "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);}//【3】把List中的数据展示在DataGridView中；    LoadDataToDataGrid(objListStudent);//【4】把DataGridView的第一行数据的明细展示在明细groupBox中；string currentSNo = dgvStudent.Rows[0].Cells[0].Value.ToString();    //通过表格读取第一行第一列，即为学号；//string currentDetail = GetStudentBySNO(currentSNo);string[] currentDetail = GetStudentBySNO(currentSNo).Split(',');  //获取当前学号学生信息，并以逗号分隔；//把当前学生展示在明细中LoadDataToDetail(currentDetail[0], currentDetail[1],currentDetail[2],currentDetail[3],currentDetail[4],currentDetail[5], currentDetail[6],currentDetail[7]);} private void dgvStudent_SelectionChanged(object sender, EventArgs e)//明细数据随着表格中选择的行为发生变化；{if (dgvStudent.CurrentRow.Selected == false) return;else{string currentSNo = dgvStudent.CurrentRow.Cells[0].Value.ToString();  //读取当前行的学号；string[] currentDetail = GetStudentBySNO(currentSNo).Split(',');LoadDataToDetail(currentDetail[0], currentDetail[1], currentDetail[2], currentDetail[3], currentDetail[4],currentDetail[5], currentDetail[6], currentDetail[7]);}}private void txtQuerySNO_TextChanged(object sender, EventArgs e)  //根据学号查询；{objListQuery.Clear();   //清空存储查询结果的List;//查询当前哪些满足条件,并添加到QueryList中；foreach(string item in objListStudent){if (item.StartsWith(txtQuerySNO.Text))//如果是查询包含某些数字的学号，可改为： item.ContainsobjListQuery.Add(item);}//清空当前表格数据dgvStudent.Rows.Clear();//把查询结果展示在DataGridView中LoadDataToDataGrid(objListQuery);}private void txtQueryMobile_TextChanged(object sender, EventArgs e) //根据手机号码查询{objListQuery.Clear();   //清空存储查询结果的List;//查询当前哪些满足条件,并添加到QueryList中；foreach (string item in objListStudent){if (item.Contains(txtQueryMobile.Text))     //是否包含查询电话；objListQuery.Add(item);}//清空当前表格数据dgvStudent.Rows.Clear();//把查询结果展示在DataGridView中LoadDataToDataGrid(objListQuery);}private void txtQueryName_TextChanged(object sender, EventArgs e)//根据姓名查询{objListQuery.Clear();   //清空存储查询结果的List;//查询当前哪些满足条件,并添加到QueryList中；foreach (string item in objListStudent){if (item.Contains(txtQueryName.Text))     //是否包含查询名字；objListQuery.Add(item);}//清空当前表格数据dgvStudent.Rows.Clear();//把查询结果展示在DataGridView中LoadDataToDataGrid(objListQuery);}             private void btnAdd_Click(object sender, EventArgs e)//添加学生信息；{//添加过程： 点击添加按钮-->数据输入-->判断数据是否有效-->提交；//控制启用和禁用；DisableButton();//让明细窗体中文本框清空txtNO.Text = string.Empty;txtName.Text = string.Empty;txtMobile.Text = string.Empty;txtHomeAddress.Text = string .Empty;txtEmali.Text = string.Empty;dtpBirthday.Text = DateTime.Now.ToString();  //日期显示为今天；rbMale.Checked = true; //默认为男生；pbCurrentPhoto.BackgroundImage = null;  //照片默认为空；//让学号的文本框获得焦点txtNO.Focus();//修改actionFlagactionFlag = 1;}private void btnUpdate_Click(object sender, EventArgs e) //修改学生信息；{//修改==删除旧的+添加新的  并到相同位置；//准备//控制按钮DisableButton();//学号不允许修改txtNO.Enabled = false;//让学生姓名文本框获得焦点txtName.Focus();//修改actionFlagactionFlag = 2;}private void btnDelete_Click(object sender, EventArgs e)//删除学生信息；{if(dgvStudent.CurrentRow.Selected == false){MessageBox.Show("删除前必须要选择某一行！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);return;}else{   string info= "您确定要删除学生 【学号："+dgvStudent.CurrentRow.Cells[0].Value.ToString()+"姓名:"+dgvStudent.CurrentRow.Cells[1].Value.ToString()+"】信息吗？？";DialogResult result= MessageBox.Show(info,"系统提示",MessageBoxButtons.YesNo, MessageBoxIcon.Question);if (result == DialogResult.Yes){string currentStudent = GetStudentBySNO(dgvStudent.CurrentRow.Cells[0].Value.ToString());foreach (string item in objListStudent){if (item.Equals(currentStudent)){objListStudent.Remove(item);  //删除；MessageBox.Show("学生信息删除成功！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);//把添加后的List展示dgvStudent.Rows.Clear();LoadDataToDataGrid(objListStudent);break;}}}else return;}}private void btnCommit_Click(object sender, EventArgs e)//提交添加和修改的操作；{if (!ValiDate()) return;  //如果返回值为false,即不满足条件直接返回else{//图片另存为： 如何保证另存为图片名称不重复（日期+时间+随机号）20201022+185020+两位随机值string photoPath = DateTime.Now.ToString("yyyyMMddHHmmss");  //年月日时分秒Random objRandom = new Random();photoPath+=objRandom.Next(0, 100).ToString("00");  //生成两位随机数，[0,100)，并转化为两位数；//再加上图像的后缀，这就需要先读取到之前的，定义一个全局变量记录上传图片时候的文件路径photoPath += photoName.Substring(photoName.Length- 4,4);   //取最后四位photoPath = ".\\image\\" + photoPath;   //保存在了相对路径  StudentManage/bin/Debug/image 中,即与生成的可执行文件在一个文件夹下；//存储Bitmap objBitmap = new Bitmap(pbCurrentPhoto.BackgroundImage);  //利用现有图片完成初始化objBitmap.Save(photoPath, pbCurrentPhoto.BackgroundImage.RawFormat);  //保存objBitmap.Dispose();//组合数据，准备添加到List中string sno = txtNO.Text.Trim();string sname = txtName.Text.Trim();string sex = rbMale.Checked == true ? "男" : "女";string birthday = dtpBirthday.Text;string mobile = txtMobile.Text;string email = txtEmali.Text;string homeAddress = txtHomeAddress.Text;// string photo = string.Empty;     //照片为空string photo = photoPath; //将图片相对路径存储；string currentStudent = sno + ',' + sname + ',' + sex + ',' + birthday + ',' + mobile + ','+ email + ',' + homeAddress + ',' + photo;switch (actionFlag){case 1:    //添加；//把数据添加到List；objListStudent.Add(currentStudent);//把添加后的List展示dgvStudent.Rows.Clear();LoadDataToDataGrid(objListStudent);//显示添加成功MessageBox.Show("学生信息添加成功！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);//控制按钮EnableButton();break;case 2:    //修改；for (int i = 0; i < objListStudent.Count;i++ )     //在所有列表中查询,用for循环是因为其能记录到位置，{if (objListStudent[i].StartsWith(sno ))  //查到第i个以该学号开头{//删除原有的objListStudent.RemoveAt(i);//插入添加的objListStudent.Insert(i, currentStudent);break;}}//把添加后的List展示dgvStudent.Rows.Clear();LoadDataToDataGrid(objListStudent);  //提示修改完成MessageBox.Show("学生信息修改成功！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);//控制按钮EnableButton();//学号文本框启用txtNO.Enabled = true;break;default:break;}}}private void btnCancle_Click(object sender, EventArgs e) //取消添加和修改的操作；{//控制按钮EnableButton();}private void btnChoosePhoto_Click(object sender, EventArgs e)//选择图片展示在PictureBox中；{//打开一个路径，选择一个图片OpenFileDialog openFile = new OpenFileDialog();    //打开文件openFile.Filter = "图片|*.png;*.jpg;*.bmp";   //图片类型if (openFile.ShowDialog() == DialogResult.OK){photoName = openFile.FileName;  //将文件名称保存到photoName ,以便在另存为时 查看图像类型pbCurrentPhoto.BackgroundImage = Image.FromFile(openFile.FileName);   //打开并展示}}private void btnClose_Click(object sender, EventArgs e) //退出{DialogResult result = MessageBox.Show("系统退出，是否保存修改", "系统提示", MessageBoxButtons.YesNo,MessageBoxIcon.Question);if (result == DialogResult.Yes){// 执行保存；// 【1】清空；File.WriteAllText(fileName, string.Empty);//【2】 把objList逐行写入StreamWriter sw = new StreamWriter(fileName, true, Encoding.Default);foreach(string item in objListStudent){sw.WriteLine(item);}sw.Close();//写入完成MessageBox.Show("写入完成！！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);}//退出Close();}//用户自定义方法；private List<string> ReadFileToList(string filePath) //把某一个文件数据读取，并以List方法返回给调用者；{List<string> objList =new List<string>();string line=string .Empty;try {  //一行行读取文件，StreamReader file =new StreamReader(filePath, Encoding.Default);while ( (line= file.ReadLine())!= null){objList.Add(line);//line = file.ReadLine();}file.Close();}catch (Exception ex){throw ex;}return objList;}private void LoadDataToDataGrid(List<string>  objList)//把List中的数据展示在DataGridView中；{//依次读取List中数据；foreach (string  item in objList){string[] studentArray = item.Split(',');   //读取的每一行，以逗号分隔开；//把读取的当前学生插入到DataGridView中；DataGridViewRow row = new DataGridViewRow();row.CreateCells(dgvStudent);row.Cells[0].Value = studentArray[0];row.Cells[1].Value = studentArray[1];row.Cells[2].Value = studentArray[2];row.Cells[3].Value = studentArray[3];row.Cells[4].Value = studentArray[4];dgvStudent.Rows.Add(row);}}private void  LoadDataToDetail(string sno, string name,string sex,string birthday,string mobile,string email,string homeAddress,string photo)//把一个学生的明细展示在明细groupbox中；{txtNO.Text = sno;txtName.Text = name;if (sex == "男") rbMale.Checked = true;else rbFemale.Checked = true;dtpBirthday.Text = birthday;txtMobile.Text = mobile;txtEmali.Text = email;txtHomeAddress.Text = homeAddress;if (photo == string.Empty) pbCurrentPhoto.BackgroundImage = null;else pbCurrentPhoto.BackgroundImage = Image.FromFile(photo);}         private string GetStudentBySNO(string  sno)  //根据学号查找某个学生的具体信息；{string currentStudent =string.Empty;foreach (string item in objListStudent){if (item.StartsWith(sno)){              currentStudent = item;break; }}return currentStudent;}private void DisableButton()//禁用按钮{//禁用按钮btnAdd.Enabled = false;btnImport.Enabled = false;btnUpdate.Enabled = false;btnDelete.Enabled = false;//启用groubboxgboxStudentDetail.Enabled = true;}private void EnableButton()//启用按钮{//启用按钮导入添加、修改、删除；btnAdd.Enabled = true;btnImport.Enabled = true;btnUpdate.Enabled = true;btnDelete.Enabled = true;//禁用groubboxgboxStudentDetail.Enabled = false;}private bool ValiDate()  //用户添加和修改后数据的校验{bool b = true;//学号和姓名不能为空，学号不能重复（添加的时候）；if (string.IsNullOrWhiteSpace(txtNO.Text)) //学号是否为空；{MessageBox.Show("学号不能为空！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);txtNO.Focus();   //让学号的文本框获得焦点b=false;}if(string.IsNullOrWhiteSpace(txtName.Text))//姓名是否为空；{MessageBox.Show("姓名不能为空！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);txtName.Focus();b=false;}if(actionFlag == 1)   //如果是添加操作{//通过方法   判断学号是否重复if (GetStudentBySNO(txtNO.Text.Trim( ))!=string .Empty){MessageBox.Show("该学号已经存在，请重新输入学号！", "系统消息", MessageBoxButtons.OK, MessageBoxIcon.Information);txtName.Focus();b=false;}}return b;}private void pictureBox1_Click(object sender, EventArgs e){}private void groupBox1_Enter(object sender, EventArgs e){}private void label3_Click(object sender, EventArgs e){}private void textBox1_TextChanged(object sender, EventArgs e){}private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e){}private void button3_Click(object sender, EventArgs e){}private void button4_Click(object sender, EventArgs e){}private void textBox2_TextChanged(object sender, EventArgs e){}private void groupBox2_Enter(object sender, EventArgs e){}private void button5_Click(object sender, EventArgs e){}private void dateTimePicker1_ValueChanged(object sender, EventArgs e){}private void label11_Click(object sender, EventArgs e){}private void Form1_Load(object sender, EventArgs e){}private void pictureBox1_Click_1(object sender, EventArgs e){}private void txtEmali_TextChanged(object sender, EventArgs e){}private void label4_Click(object sender, EventArgs e){}private void pictureBox2_Click(object sender, EventArgs e){}private void gboxStudentQuery_TextChanged(object sender, EventArgs e){}private void pbCurrentPhoto_Click(object sender, EventArgs e){}}
}

参考：1. Here