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Winform的三层架构详细案例分析

Winform的三层架构详细案例分析

hygge
2022-11-23 / 0 评论 / 23 阅读 / 正在检测是否收录...
写了几个Winform程序后发现一个类的行数直逼2000行...维护十分困难,想起来之前学过三层架构,转篇文章记录一下!

三层架构将整个业务应用划分为:(1)界面UI层;(2)业务逻辑层;(3)数据访问层。

对于复杂的系统分层可以让结构更加清晰,模块更加独立,便于维护。

latlkjf4.png

各层的任务:

(1)数据访问层:负责数据库的操作。

(2)业务逻辑层:实现功能模块的业务逻辑。

(3)界面UI层:绘制界面,以及负责界面相关代码。

(4)实体类:将数据库中的表转化为面向对象思想中的类。

一、案例需求

使用三层架构实现学生管理:

latlkv3f.png

(1)专业下拉框绑定专业表数据,网格控件绑定学生数据,并且点击"搜索"按钮可以多条件组合查询。

(2)选中某一行,右键可以弹出"删除"菜单,点击"删除"菜单可以删除学生数据。

(3)点击"新增"按钮,弹出新增窗体,在此窗体中完成学生的新增操作。

latll1wg.png

(4)选中某一行,点击"编辑"按钮,弹出编辑窗体,在此窗体中完成数据的修改。

latll746.png

备注:其中性别的单选框,以及爱好的多选框分别用两个Pannel容器包含。

数据库准备:

--专业
create table ProfessionInfo
(
    ProfessionID int primary key identity(1,1), --专业编号
    ProfessionName varchar(50) not null unique --专业名称
)
--学生
create table StudentInfo
(
    StuID varchar(20) primary key,  --学生学号
    StuName varchar(50) not null,        --学生姓名
    StuAge int not null check(StuAge > 0 and StuAge < 130), --学生年龄
    StuSex char(2) not null check(StuSex in('男','女')),  --学生性别
    StuHobby nvarchar(100), --爱好
    ProfessionID int not null references ProfessionInfo(ProfessionID), --所属专业编号
)
--添加专业信息
insert into ProfessionInfo(ProfessionName) values('电子竞技')
insert into ProfessionInfo(ProfessionName) values('软件开发')
insert into ProfessionInfo(ProfessionName) values('医疗护理')
--插入学生信息
insert into StudentInfo(StuID,StuName,StuAge,StuSex,StuHobby,ProfessionID)
values('001','刘备',18,'男','',1)
insert into StudentInfo(StuID,StuName,StuAge,StuSex,StuHobby,ProfessionID)
values('002','关羽',20,'男','',2)
insert into StudentInfo(StuID,StuName,StuAge,StuSex,StuHobby,ProfessionID)
values('003','张飞',19,'男','',2)
insert into StudentInfo(StuID,StuName,StuAge,StuSex,StuHobby,ProfessionID)
values('004','孙尚香',17,'女','',3)

二、项目结构

(1)创建一个空白解决方案。

(2)在解决方案中创建类库项目MyEntity代表"实体类"。

(3)在解决方案中创建类库项目MyDAL代表"数据访问层"。

(4)在解决方案中创建类库项目MyBLL代表"业务逻辑层"。

(5)在解决方案中创建Windows窗体应用程序MyUI代表"界面UI层"。

latllgoa.png

三、实体类编写

在MyEntity项目中添加两个实体类,实体类代码如下:

ProfessionInfoEntity:

public class ProfessionInfoEntity
{
    public ProfessionInfoEntity()
    {
        this.ProfessionID = 0;
        this.ProfessionName = "";
    }
    public int ProfessionID { get; set; }  //专业编号
    public string ProfessionName { get; set; }//专业名称
}

StudentInfoEntiy:

public class StudentInfoEntiy
{
    public StudentInfoEntiy()
    {
        this.StuID = "";
        this.StuName = "";
        this.StuAge = 0;
        this.StuSex = "";
        this.StuHobby = "";
        this.ProfessionID = 0;
        this.ProfessionName = "";
    }
    public string StuID { get; set; }  //学生学号
    public string StuName { get; set; }  //学生姓名
    public int StuAge { get; set; }  //学生年龄
    public string StuSex { get; set; }  //学生性别
    public string StuHobby { get; set; }  //学生爱好
    public int ProfessionID { get; set; }  //学生所属专业编号
    public string ProfessionName { get; set; } //学生所属专业名称
}

四、数据访问层编写

(1)由于数据访问层需要使用实体类,所以需要添加实体类的引用。

即在MyDAL项目上右键-->添加-->引用-->项目,在项目中勾选MyEntity项目。

(2)将之前封装好的DBHelper文件复制到MyDAL项目中,并通过添加现有项,将DBHelper加入项目。

(3)在MyDAL项目中添加两个类,类代码如下:

ProfessionInfoDAL:

public class ProfessionInfoDAL
{
    #region 新增
    public int Add(ProfessionInfoEntity entity)
    {
        string sql = "insert into ProfessionInfo(professionName) values(@professionName)";
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("ProfessionName",entity.ProfessionName);
        return DBHelper.ExecNonQuery();
    }
    #endregion

    #region 删除
    public int Delete(int id)
    {
        string sql = "delete from ProfessionInfo where ProfessionID=@ProfessionID";
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("ProfessionID", id);
        return DBHelper.ExecNonQuery();
    }
    #endregion

    #region 修改
    public int Update(ProfessionInfoEntity entity)
    {
        string sql = "update ProfessionInfo set professionName=@professionName where ProfessionID=@ProfessionID";
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("professionName", entity.ProfessionName);
        DBHelper.SetParameter("ProfessionID", entity.ProfessionID);
        return DBHelper.ExecNonQuery();
    }
    #endregion

    #region 列表
    public List<ProfessionInfoEntity> List()
    {
        string sql = "select * from ProfessionInfo";
        DataTable dt = new DataTable();
        DBHelper.PrepareSql(sql);
        dt = DBHelper.ExecQuery();
        List<ProfessionInfoEntity> list = new List<ProfessionInfoEntity>();
        foreach (DataRow item in dt.Rows)
        {
            ProfessionInfoEntity entity = new ProfessionInfoEntity();
            entity.ProfessionID = int.Parse(item["ProfessionID"].ToString());
            entity.ProfessionName = item["ProfessionName"].ToString();
            list.Add(entity);
        }
        return list;
    }
    #endregion

    #region 详情
    public ProfessionInfoEntity Detail(int id)
    {
        string sql = "select * from ProfessionInfo where ProfessionID=@ProfessionID";
        DataTable dt = new DataTable();
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("ProfessionID", id);
        dt = DBHelper.ExecQuery();
        if (dt.Rows.Count == 0)
            return null;
        ProfessionInfoEntity entity = new ProfessionInfoEntity();
        entity.ProfessionID = int.Parse(dt.Rows[0]["ProfessionID"].ToString());
        entity.ProfessionName = dt.Rows[0]["ProfessionName"].ToString();
        return entity;
    }
    #endregion
}

StudentInfoDAL:

public class StudentInfoDAL
{
    #region 新增
    public int Add(StudentInfoEntiy entity)
    {
        string sql = "insert into StudentInfo(StuID,StuName,StuAge,StuSex,StuHobby,ProfessionID) values(@StuID,@StuName,@StuAge,@StuSex,@StuHobby,@ProfessionID)";
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("StuID", entity.StuID);
        DBHelper.SetParameter("StuName", entity.StuName);
        DBHelper.SetParameter("StuAge", entity.StuAge);
        DBHelper.SetParameter("StuSex", entity.StuSex);
        DBHelper.SetParameter("StuHobby", entity.StuHobby);
        DBHelper.SetParameter("ProfessionID", entity.ProfessionID);
        return DBHelper.ExecNonQuery();
    }
    #endregion

    #region 删除
    public int Delete(string id)
    {
        string sql = "delete from StudentInfo where StuID=@StuID";
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("StuID", id);
        return DBHelper.ExecNonQuery();
    }
    #endregion

    #region 修改
    public int Update(StudentInfoEntiy entity)
    {
        string sql = "update StudentInfo set StuName=@StuName,StuAge=@StuAge,StuSex=@StuSex,StuHobby=@StuHobby,ProfessionID=@ProfessionID where StuID=@StuID";
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("StuName", entity.StuName);
        DBHelper.SetParameter("StuAge", entity.StuAge);
        DBHelper.SetParameter("StuSex", entity.StuSex);
        DBHelper.SetParameter("StuHobby", entity.StuHobby);
        DBHelper.SetParameter("ProfessionID", entity.ProfessionID);
        DBHelper.SetParameter("StuID", entity.StuID);
        return DBHelper.ExecNonQuery();
    }
    #endregion

    #region 列表
    public List<StudentInfoEntiy> List()
    {
        string sql = "select * from StudentInfo";
        DataTable dt = new DataTable();
        DBHelper.PrepareSql(sql);
        dt = DBHelper.ExecQuery();
        List<StudentInfoEntiy> list = new List<StudentInfoEntiy>();
        foreach (DataRow item in dt.Rows)
        {
            StudentInfoEntiy entity = new StudentInfoEntiy();
            entity.StuID = item["StuID"].ToString();
            entity.StuName = item["StuName"].ToString();
            entity.StuAge = int.Parse(item["StuAge"].ToString());
            entity.StuSex = item["StuSex"].ToString();
            entity.StuHobby = item["StuHobby"].ToString();
            entity.ProfessionID = int.Parse(item["ProfessionID"].ToString());
            list.Add(entity);
        }
        return list;
    }
    #endregion

    #region 详情
    public StudentInfoEntiy Detail(string id)
    {
        string sql = "select * from StudentInfo where StuID=@StuID";
        DataTable dt = new DataTable();
        DBHelper.PrepareSql(sql);
        DBHelper.SetParameter("StuID", id);
        dt = DBHelper.ExecQuery();
        if (dt.Rows.Count == 0)
            return null;
        StudentInfoEntiy entity = new StudentInfoEntiy();
        entity.StuID = dt.Rows[0]["StuID"].ToString();
        entity.StuName = dt.Rows[0]["StuName"].ToString();
        entity.StuAge = int.Parse(dt.Rows[0]["StuAge"].ToString());
        entity.StuSex = dt.Rows[0]["StuSex"].ToString();
        entity.StuHobby = dt.Rows[0]["StuHobby"].ToString();
        entity.ProfessionID = int.Parse(dt.Rows[0]["ProfessionID"].ToString());
        return entity;
    }
    #endregion
}

五、业务逻辑层编写

(1)由于业务逻辑层需要使用实体类,所以需要添加实体类的引用。

即在MyBLL项目上右键-->添加-->引用-->项目,在项目中勾选MyEntity项目。

(2)由于业务逻辑层需要调用数据访问层,所以需要添加数据访问层的引用。

即在MyBLL项目上右键-->添加-->引用-->项目,在项目中勾选MyDAL项目。

(3)在MyBLL项目中添加两个类,类代码如下:

ProfessionInfoBLL:

public class ProfessionInfoBLL
{
    ProfessionInfoDAL dal = new ProfessionInfoDAL();
    #region 新增
    public int Add(ProfessionInfoEntity entity)
    {
        return dal.Add(entity);
    }
    #endregion

    #region 删除
    public int Delete(int id)
    {
        return dal.Delete(id);
    }
    #endregion

    #region 修改
    public int Update(ProfessionInfoEntity entity)
    {
        return dal.Update(entity);
    }
    #endregion

    #region 列表
    public List<ProfessionInfoEntity> List()
    {
        return dal.List();
    }
    #endregion

    #region 详情
    public ProfessionInfoEntity Detail(int id)
    {
        return dal.Detail(id);
    }
    #endregion
}

StudentInfoBLL:

public class StudentInfoBLL
{
    StudentInfoDAL dal = new StudentInfoDAL();
    #region 新增
    public int Add(StudentInfoEntiy entity)
    {
        return dal.Add(entity);
    }
    #endregion

    #region 删除
    public int Delete(string id)
    {
        return dal.Delete(id);
    }
    #endregion

    #region 修改
    public int Update(StudentInfoEntiy entity)
    {
        return dal.Update(entity);
    }
    #endregion

    #region 列表
    public List<StudentInfoEntiy> List()
    {
        return dal.List();
    }
    #endregion

    #region 详情
    public StudentInfoEntiy Detail(string id)
    {
        return dal.Detail(id);
    }
    #endregion
}

六、界面UI层代码编写

(1)由于界面UI层需要使用实体类,所以需要添加实体类的引用。

即在MyUI项目上右键-->添加-->引用-->项目,在项目中勾选MyEntity项目。

(2)由于界面UI层需要调用业务逻辑层,所以需要添加业务逻辑层的引用。

即在MyUI项目上右键-->添加-->引用-->项目,在项目中勾选MyBLL项目。

查询窗体界面及代码:

latlmksp.png

(1)由于查询学生需要多条件组合查询,所以给数据访问层和业务逻辑层添加条件搜索的方法。

给数据访问层MyDAL中StudentInfoDAL类添加方法:

#region 条件查询
public List<StudentInfoEntiy> Search(StudentInfoEntiy searchObj)
{
    string sql = "select * from StudentInfo inner join ProfessionInfo on StudentInfo.ProfessionID = ProfessionInfo.ProfessionID where 1 = 1";
    if (searchObj.ProfessionID != 0)
        sql += " and StudentInfo.ProfessionID = " + searchObj.ProfessionID;
    if (!searchObj.StuName.Equals(""))
        sql += " and StuName like '%" + searchObj.StuName + "%'";
    DataTable dt = new DataTable();
    DBHelper.PrepareSql(sql);
    dt = DBHelper.ExecQuery();
    List<StudentInfoEntiy> list = new List<StudentInfoEntiy>();
    foreach (DataRow item in dt.Rows)
    {
        StudentInfoEntiy entity = new StudentInfoEntiy();
        entity.StuID = item["StuID"].ToString();
        entity.StuName = item["StuName"].ToString();
        entity.StuAge = int.Parse(item["StuAge"].ToString());
        entity.StuSex = item["StuSex"].ToString();
        entity.StuHobby = item["StuHobby"].ToString();
        entity.ProfessionID = int.Parse(item["ProfessionID"].ToString());
        entity.ProfessionName = item["ProfessionName"].ToString();
        list.Add(entity);
    }
    return list;
}
#endregion

给业务逻辑层MyBLL中StudentInfoBLL类添加方法:

#region 条件查询
public List<StudentInfoEntiy> Search(StudentInfoEntiy searchObj)
{
    return dal.Search(searchObj);
}
#endregion

(2)在此界面中多个功能需要调用业务逻辑层,定义两个业务逻辑层对象:

ProfessionInfoBLL proBll = new ProfessionInfoBLL();
StudentInfoBLL stuBll = new StudentInfoBLL();

(3)查询窗体绑定专业信息、绑定学生信息以及搜索功能代码:

#region 绑定下拉框
private void BindPro()
{
    List<ProfessionInfoEntity> list = new List<ProfessionInfoEntity>();
    list = proBll.List();
    list.Insert(0,new ProfessionInfoEntity { ProfessionID=0,ProfessionName="--请选择--"});
    this.cmbPro.DataSource = list;
    this.cmbPro.DisplayMember = "ProfessionName";
    this.cmbPro.ValueMember = "ProfessionID";
}
#endregion

#region 绑定学生数据
private void BindData()
{
    StudentInfoEntiy searchObj = new StudentInfoEntiy();
    searchObj.ProfessionID = int.Parse(this.cmbPro.SelectedValue.ToString());
    searchObj.StuName = this.txtName.Text;
    this.dataGridView1.AutoGenerateColumns = false;
    this.dataGridView1.DataSource = stuBll.Search(searchObj);
}
#endregion

#region 窗体加载
private void FrmSelect_Load(object sender, EventArgs e)
{
    BindPro();
    BindData();
}
#endregion

#region 搜索按钮
private void btSearch_Click(object sender, EventArgs e)
{
    BindData();
}
#endregion

(4)删除菜单代码:

private void 删除ToolStripMenuItem_Click(object sender, EventArgs e)
{
    //添加是否确定删除的对话框
    DialogResult result = MessageBox.Show("确定要删除数据吗,删除之后无法恢复!", "提示框",
        MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
    if (result == DialogResult.Cancel)
        return;
    string stuid = this.dataGridView1.SelectedRows[0].Cells[0].Value.ToString();
    if(stuBll.Delete(stuid) == 1)
        MessageBox.Show("删除成功!");
    else
        MessageBox.Show("删除失败!");
    BindData();
}

新增窗体界面及代码:

latlmwm5.png

ProfessionInfoBLL proBll = new ProfessionInfoBLL();
StudentInfoBLL stuBll = new StudentInfoBLL();
#region 绑定下拉框
private void BindPro()
{
    List<ProfessionInfoEntity> list = new List<ProfessionInfoEntity>();
    list = proBll.List();
    list.Insert(0, new ProfessionInfoEntity { ProfessionID = 0, ProfessionName = "--请选择--" });
    this.cmbPro.DataSource = list;
    this.cmbPro.DisplayMember = "ProfessionName";
    this.cmbPro.ValueMember = "ProfessionID";
}
#endregion
private void FrmAdd_Load(object sender, EventArgs e)
{
    BindPro();
}

private void btAdd_Click(object sender, EventArgs e)
{
    //性别处理
    string sex = "";
    if (this.rbBoy.Checked == true) sex = this.rbBoy.Text;
    if (this.rbGirl.Checked == true) sex = this.rbGirl.Text;
    //爱好处理
    string hobby = "";
    foreach (CheckBox ck in this.panel2.Controls)
    {
        if (ck.Checked == true)
        {
            if (!hobby.Equals(""))
                hobby += ",";
            hobby += ck.Text;
        }
    }
    StudentInfoEntiy entity = new StudentInfoEntiy();
    entity.StuID = this.txtId.Text;
    entity.StuName = this.txtName.Text;
    entity.StuAge = int.Parse(this.txtAge.Text);
    entity.StuSex = sex;
    entity.StuHobby = hobby;
    entity.ProfessionID = int.Parse(this.cmbPro.SelectedValue.ToString());
    if (stuBll.Add(entity) == 1)
        MessageBox.Show("新增成功!");
    else
        MessageBox.Show("新增失败!");
    this.Close();
}

编辑修改窗体界面及代码:

latln4bd.png

public string StuID { get; set; } //学生编号
ProfessionInfoBLL proBll = new ProfessionInfoBLL();
StudentInfoBLL stuBll = new StudentInfoBLL();
#region 绑定下拉框
private void BindPro()
{
    List<ProfessionInfoEntity> list = new List<ProfessionInfoEntity>();
    list = proBll.List();
    list.Insert(0, new ProfessionInfoEntity { ProfessionID = 0, ProfessionName = "--请选择--" });
    this.cmbPro.DataSource = list;
    this.cmbPro.DisplayMember = "ProfessionName";
    this.cmbPro.ValueMember = "ProfessionID";
}
#endregion

#region 绑定详情
private void BindDetail()
{
    StudentInfoEntiy entity = new StudentInfoEntiy();
    entity = stuBll.Detail(this.StuID);
    this.txtId.Text = entity.StuID;
    this.txtName.Text = entity.StuName;
    this.txtAge.Text = entity.StuAge.ToString();
    this.cmbPro.SelectedValue = entity.ProfessionID;
    //性别处理
    if (entity.StuSex.Equals("男"))
        this.rbBoy.Checked = true;
    else
        this.rbGirl.Checked = true;
    //爱好处理
    string[] arrHobby = entity.StuHobby.Split(',');
    foreach (string hobby in arrHobby)
    {
        foreach (CheckBox ck in this.panel2.Controls)
        {
            if (ck.Text.Equals(hobby))
                ck.Checked = true;
        }
    }
}
#endregion

private void FrmEdit_Load(object sender, EventArgs e)
{
    BindPro();
    BindDetail();
}

private void btUpdate_Click(object sender, EventArgs e)
{
    //性别处理
    string sex = "";
    if (this.rbBoy.Checked == true) sex = this.rbBoy.Text;
    if (this.rbGirl.Checked == true) sex = this.rbGirl.Text;
    //爱好处理
    string hobby = "";
    foreach (CheckBox ck in this.panel2.Controls)
    {
        if (ck.Checked == true)
        {
            if (!hobby.Equals(""))
                hobby += ",";
            hobby += ck.Text;
        }
    }
    StudentInfoEntiy entity = new StudentInfoEntiy();
    entity.StuID = this.txtId.Text;
    entity.StuName = this.txtName.Text;
    entity.StuAge = int.Parse(this.txtAge.Text);
    entity.StuSex = sex;
    entity.StuHobby = hobby;
    entity.ProfessionID = int.Parse(this.cmbPro.SelectedValue.ToString());
    if (stuBll.Update(entity) == 1)
        MessageBox.Show("修改成功!");
    else
        MessageBox.Show("修改失败!");
    this.Close();
}

查询窗体中"新增"和"编辑"按钮代码:

private void btAdd_Click(object sender, EventArgs e)
{
    FrmAdd frm = new FrmAdd();
    frm.Show();
}

private void btEdit_Click(object sender, EventArgs e)
{
    string stuid = this.dataGridView1.SelectedRows[0].Cells[0].Value.ToString();
    FrmEdit frm = new FrmEdit();
    frm.StuID = stuid;
    frm.Show();
}

本文来自博客园,作者:码农阿亮,转载请注明原文链接:https://www.cnblogs.com/wml-it/p/15967883.html

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