实现窗体效果图：
Model层：（实体层）
DAL层：（数据访问层）
首先在DAL层建一个SQLHelper类，进行数据库的连接，其次在StudentDAL类中书写一个ISLogin方法，进行与数据库的交互登录。
BLL层：（业务逻辑层）
在业务逻辑层进行调用，调用DAL层的登录方法，StudentBLL进行逻辑处理然后传递到UI层。
UI层:（表示层）
进行判断后登录到主界面。
按姓名查询展示效果图：
首先在DAL层StudentDAL类中写一个GetAllStudent（）方法：
BLL层进行方法调用，逻辑处理后传递到UI，和上面差不多。
主要说一下UI层，进行窗体绑定。
调用BLL，用list接收进行方法调用，最后绑定数据进行展示。
添加学生信息效果图：
StudentDAL层
//添加学生 public bool AddStudent(Student stu) { bool flag = false; string sql = "insert into Student Values(@LoginPwd,@StudentName,@Gender,@GradeId,@Phone,@Address,@Birthday,@Email)"; SqlParameter []para= { new SqlParameter("@LoginPwd",stu.LoginPwd), new SqlParameter("@StudentName",stu.StudentName), new SqlParameter("@Gender",stu.Gender), new SqlParameter("@GradeId",stu.GradeId), new SqlParameter("@Phone",stu.Phone), new SqlParameter("@Address",stu.Address), new SqlParameter("@Birthday",stu.Birthday), new SqlParameter("@Email",stu.Email), }; int count = SQLHelper.ExecuteNonQuery(sql,para); if(count>0) { flag = true; } return flag; } StudentBLL层
//添加学生 public bool AddStudent(Student stu) { bool result = dal.AddStudent(stu); return result; } UI层
//保存 private void btnEdit_Click(object sender, EventArgs e) { //从界面获取各个值 Student stu = new Student(); stu.LoginPwd = txtPwd.Text; stu.StudentName = txtName.Text; stu.Gender = rbtnFemale.Checked?"0":"1"; stu.Phone = txtPhone.Text; stu.Address = txtAddress.Text; stu.Email = txtEmail.Text; //出生日期 stu.Birthday = dpBirthday.Value; //年级编号 stu.GradeId = Convert.ToInt32(cboGrade.SelectedValue); bool result = studal.AddStudent(stu); if (result) { MessageBox.Show("添加成功！"); } else { MessageBox.Show("添加失败！"); } } 加载学生信息<查询>效果图：
DAL层
返回的是泛型集合、可使用MyTool工具类或者foreach遍历
//泛型 public ListGetAllStudent() { // List list = new List (); string sql = "select * from Student"; DataTable dt= SQLHelper.ExecuteDataTable(sql); MyTool tool = new MyTool(); List list = tool.DataTableToList (dt); //foreach (DataRow item in dt.Rows) //{ // Student stu = new Student(); // stu.StudentName = item["StudentName"].ToString(); // stu.StudentNo = Convert.ToInt32(item["StudentNo"]); // stu.LoginPwd =item["LoginPwd"].ToString(); // list.Add(stu); //} return list; }
BLL层
//泛型 public ListGetAllStudent() { List list = dal.GetAllStudent(); return list; }
UI层
StudentBLL stuBll = new StudentBLL(); GradeBLL GBll = new GradeBLL(); //主窗体 private void FrmSearchByGrade_Load(object sender, EventArgs e) { //删除英文列 dgvList.AutoGenerateColumns = false; List list= stuBll.GetAllStudent(); dgvList.DataSource = list; List glist = GBll.GetAllGrade(); //绑定年级下拉框值 cboGrade.ValueMember = "GradeId"; cboGrade.DisplayMember = "GradeName"; cboGrade.DataSource = glist; } //查询 private void btnSearch_Click(object sender, EventArgs e) { int gradeid =Convert.ToInt32(cboGrade.SelectedValue); //使用BLL层 List list = stuBll.ByGradeId(gradeid); dgvList.DataSource = list; } 删除学生信息效果图：
DAL层
//删除 public bool Delete(int stuNo) { bool flag = false; string sql="delete from Student where StudentNo=@No"; SqlParameter para = new SqlParameter("@No",stuNo); int count = SQLHelper.ExecuteNonQuery(sql,para); if(count>0) { flag = true; } return flag; } BLL层
//删除 public bool Delete(int stuNo) { return dal.Delete(stuNo); } UI层
经验：光标位置
记录选中行的索引值 定义变量index、光标回到index-1
//删除 private void tsmi_del_Click(object sender, EventArgs e) { int stuno = Convert.ToInt32(dgvList.SelectedRows[0].Cells["Column2"].Value); //记录选中行的索引值 int index = dgvList.CurrentRow.Index; //MessageBox.Show(index.ToString()); bool flag = stuBll.Delete(stuno); if(flag) { MessageBox.Show("删除成功！"); List list = stuBll.GetAllStudent(); dgvList.DataSource = list; //光标回到index-1 dgvList[0, index].Selected = true; dgvList.CurrentCell=dgvList[0,index]; } } 修改学生信息效果图：
DAL层
//修改 public bool UpdateInfo(Student stu) { bool flag = false; string sql = "update Student set StudentName=@stuName,Gender=@gender,Birthday=@birthday where StudentNo=@No"; SqlParameter[] para = { new SqlParameter("@stuName",stu.StudentName), new SqlParameter("@gender",stu.Gender), new SqlParameter("@birthday",stu.Birthday), new SqlParameter("@No",stu.StudentNo) }; int count = SQLHelper.ExecuteNonQuery(sql,para); if(count>0) { flag = true; } return flag; } BLL层：
//修改 public bool UpdateInfo(Student stu) { return dal.UpdateInfo(stu); } 窗体的关联：
private void tsmi_update_Click(object sender, EventArgs e) { FrmUpdate frm = new FrmUpdate(); frm.dgvList = dgvList; frm.Show(); } UI层 Load事件中实现窗体的传值
StudentBLL stubll = new StudentBLL(); public DataGridView dgvList; Student stu = new Student(); private void FrmUpdate_Load(object sender, EventArgs e) { stu.StudentNo = Convert.ToInt32(dgvList.SelectedRows[0].Cells["Column2"].Value); stu.StudentName = dgvList.SelectedRows[0].Cells["name"].Value.ToString(); stu.Gender = dgvList.SelectedRows[0].Cells["Column3"].Value.ToString(); stu.Birthday = Convert.ToDateTime(dgvList.SelectedRows[0].Cells["Column4"].Value); // MessageBox.Show(stu.StudentName.ToString()); this.txtNo.Text = stu.StudentNo.ToString(); this.txtName.Text = stu.StudentName; this.txtGender.Text = stu.Gender; this.txtBirthday.Text = stu.Birthday.ToString(); } private void btnUpdate_Click(object sender, EventArgs e) { stu.StudentName = txtName.Text; stu.Gender = txtGender.Text; stu.Birthday = Convert.ToDateTime(txtBirthday.Text); bool flag = stubll.UpdateInfo(stu); if(flag) { MessageBox.Show("修改成功！！"); List list = stubll.GetAllStudent(); dgvList.DataSource = list; } }