学生管理系统----(分层开发)
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一：分层架构
搭建DAL层(数据访问层)、UI层(表示层)、BLL层(业务逻辑层)以及Model层(实体层)
各层的引用关系：
DAL、UI、BLL层引用Model层
UI层引用BLL层
BLL层引用DAL层
二：实现登录功能
DAL层：（为了防止sql注入需要使用SqlParameter）
//登录 public bool LoginStudent(Student stu) { bool flag = false; string sql = "select count(1) from Student where StudentName=@name and LoginPwd=@pwd"; SqlParameter[] para = { new SqlParameter("@name",stu.StudentName), new SqlParameter("@pwd",stu.LoginPwd) }; int count=Convert.ToInt32(SQLHelper.ExecuteScalar(sql,para)); if (count > 0) { flag = true; } return flag; }
BLL层：（只做数据传递的载体）
StudentDAL dal = new StudentDAL(); //登录 public bool IsLogin(Student stu) { bool result = dal.LoginStudent(stu); return result; }
UI层：
private void btnLogin_Click(object sender, EventArgs e) { StudentBLL bll = new StudentBLL(); Student stu = new Student(); stu.StudentName = txtName.Text; stu.LoginPwd = txtPwd.Text; bool result=bll.IsLogin(stu); if (result) { MessageBox.Show("登录成功！"); FrmMain frm = new FrmMain(); this.Hide(); frm.Show(); } else { MessageBox.Show("失败啦！"); } }
效果：
登录成功后进入主界面
三 实现新增学生用户
效果：
DAL层：
//添加学生 public bool AddStudent(Student stu) { bool flag = false; string sql = "insert into Student values(\'"+stu.StudentNo+"\',\'"+stu.LoginPwd+"\',\'"+stu.StudentName+"\',\'"+stu.Sex+"\',\'"+stu.GradeId+"\',\'"+stu.Phone+"\',\'"+stu.Address+"\',\'"+stu.BornDate+"\',\'"+stu.Email+"\')"; int count = SQLHelper.ExecuteNonQuery(sql); if (count > 0) { flag = true; } return flag; }
BLL层：
//添加 public bool Add(Student stu) { bool result = dal.AddStudent(stu); return result; }
UI层：
private void btnEdit_Click(object sender, EventArgs e) { stu.StudentNo = txtStudentNo.Text; stu.LoginPwd = txtPwd.Text; stu.StudentName = txtName.Text; stu.Sex = rbtnFemale.Checked ? "0" : "1"; stu.GradeId = Convert.ToInt32(cboGrade.SelectedValue); stu.Phone = txtPhone.Text; stu.Address = txtAddress.Text; stu.BornDate = dpBirthday.Value; stu.Email = txtEmail.Text; if (txtPwd.Text.Trim() != txtRePwd.Text.Trim()) { MessageBox.Show("密码请输入一致!"); return; } bool re = bll.Add(stu); if (re) { MessageBox.Show("添加成功!"); } else { MessageBox.Show("添加失败!"); } }
四 加载学生信息<查询>
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 List<Student> GetAllStudent() { // List<Student> list = new List<Student>(); string sql = "select * from Student"; DataTable dt= SQLHelper.ExecuteDataTable(sql); MyTool tool = new MyTool(); List<Student> list = tool.DataTableToList<Student>(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 List<Student> GetAllStudent() { List<Student> 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<Student>list= stuBll.GetAllStudent(); dgvList.DataSource = list; List<Grade> 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<Student> list = stuBll.ByGradeId(gradeid); dgvList.DataSource = list; }
五 删除学生信息
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
注：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<Student> list = stuBll.GetAllStudent(); dgvList.DataSource = list; //光标回到index-1 dgvList[0, index].Selected = true; dgvList.CurrentCell=dgvList[0,index]; } }
六 修改学生信息
DAL层
//修改 public bool UpdateInfo(Student stu) { bool flag = false; string sql = "update Student set StudentName=@stuName,Sex=@gender,BornDate=@birthday where StudentNo=@No"; SqlParameter[] para = { new SqlParameter("@stuName",stu.StudentName), new SqlParameter("@Sex",stu.Gender), new SqlParameter("@BornDate",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.Sex= dgvList.SelectedRows[0].Cells["Column3"].Value.ToString(); stu.BornDate= 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.Sex; this.txtBirthday.Text = stu.BornDate.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<Student> list = stubll.GetAllStudent(); dgvList.DataSource = list; } }
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