【Windows Form 实战】学生成绩管理系统(五) 学生模块设计

学生Form

1、界面设计

很简单，就是3个表格，分别显示个人信息、各科目成绩、可选课程。
一个TabControl容器里加了3个tabPage，中间那个黑框是DataGridView，每个tabPage各有一个DataGridView。设置TabControl的Dock属性为Fill，就会自动充满窗口。由于显示的内容不多，窗口和DataGridView的大小自己调整。

DataGridView设置如下：

2、frmStudent.cs

using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data;

namespace SSMS
{
    public partial class frmStudent : Form
    {
        frmLogin myLoginForm;
        public frmStudent(frmLogin afrmLogin = null)
        {
            myLoginForm = afrmLogin;
            InitializeComponent();
        }

        private void frmStudent_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (myLoginForm != null)
            {
                myLoginForm.Close();
            }
        }

        private void frmStudent_Load(object sender, System.EventArgs e)
        {
            string sqlStrPersonalInfo = @"select * from {0} where {1}='{2}'";
            sqlStrPersonalInfo = string.Format(sqlStrPersonalInfo, Data.t_student, Data.c_student_snum, Data.loginID);

            string sqlStrScore = @"select * from {0} where {1}='{2}'";
            sqlStrScore = string.Format(sqlStrScore, Data.t_sc, Data.c_sc_snum, Data.loginID);

            SqlDataAdapter sda = new SqlDataAdapter(sqlStrPersonalInfo,Data.connectionString);
            DataSet ds = new DataSet();
            sda.Fill(ds, "table1");

            sda = new SqlDataAdapter(sqlStrScore,Data.connectionString);
            sda.Fill(ds, "table2");

            dataGridView1.DataSource = ds.Tables["table1"];
            dataGridView2.DataSource = ds.Tables["table2"];
        }
    }
}

SqlDataAdapter: using System.Data.SqlClient;
DataSet: using System.Data;
给frmStudent绑定frmStudent_Load事件，这个事件是在窗口加载的时候做的事情。此后事件绑定操作无需再叙述，相信大家都已经掌握了：

运行一下，用一个学生的账号密码登录一下，101吧，先看看显示效果:

看起来不错，但是我们想把个人信息表格的列名显示成学号，姓名，班级，而且个人成绩只想显示课程名称和成绩。这就涉及到了多表查询了，需要有一定的数据库SQL知识基础。修改如下：

private void frmStudent_Load(object sender, System.EventArgs e)
{
    string sqlStrPersonalInfo = @"select * from {0} where {1}='{2}'";
    sqlStrPersonalInfo = string.Format(sqlStrPersonalInfo, Data.t_student, Data.c_student_snum, Data.loginID);

    string sc_cnum = Data.t_sc + "." + Data.c_sc_cnum;
    string course_cnum = Data.t_course + "." + Data.c_course_cnum;

    string sqlStrScore = @"select {0},{1} from {2},{3} where {4}='{5}' and {6}={7}";
    sqlStrScore = string.Format(sqlStrScore,
        Data.c_course_cname, Data.c_sc_score,
        Data.t_sc, Data.t_course,
        Data.c_sc_snum, Data.loginID,
        sc_cnum, course_cnum
        );


    SqlDataAdapter sda = new SqlDataAdapter(sqlStrPersonalInfo,Data.connectionString);
    DataSet ds = new DataSet();
    sda.Fill(ds, "table1");

    sda = new SqlDataAdapter(sqlStrScore,Data.connectionString);
    sda.Fill(ds, "table2");

    dataGridView1.DataSource = ds.Tables["table1"];
    dataGridView2.DataSource = ds.Tables["table2"];

    dataGridView1.Columns[Data.c_student_snum].HeaderText = "学号";
    dataGridView1.Columns[Data.c_student_sname].HeaderText = "姓名";
    dataGridView1.Columns[Data.c_student_sclass].HeaderText = "班级";

    dataGridView2.Columns[Data.c_course_cname].HeaderText = "课程名称";
    dataGridView2.Columns[Data.c_sc_score].HeaderText = "分数";

}

显示如下：

似乎好了，但是新的问题又来了，个人成绩这个表格由于少了一列又显示不太美观了，别担心，办法总是有的:

1、Data.cs中columnAutoAdapter函数就是解决这个问题的

/// 

/// 自动调整列宽，以适应表格大小
/// 
/// 需要被调整的DataGridView对象
public static void columnAutoAdapter(DataGridView dv)
{
    int totalWidth = 0;
    for (int i = 0; i < dv.Columns.Count; i++)
    {
        totalWidth += dv.Columns[i].Width;//记录整个DataGridView的宽度
    }
    for (int i = 0; i < dv.Columns.Count; i++)
    {
        dv.Columns[i].FillWeight = (dv.Columns[i].Width * 100) / totalWidth;
    }
    dv.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill;
}

2、frmStudent.cs加两句方法调用：

private void frmStudent_Load(object sender, System.EventArgs e)
{
    ...

    dataGridView2.Columns[Data.c_course_cname].HeaderText = "课程名称";
    dataGridView2.Columns[Data.c_sc_score].HeaderText = "分数";

    Data.columnAutoAdapter(dataGridView1);
    Data.columnAutoAdapter(dataGridView2);
}

再看看效果，虽然不是很完美，但比之前的好多了，不是吗。

最终代码

using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data;
using System.Collections;

namespace SSMS
{
    public partial class frmStudent : Form
    {
        frmLogin myLoginForm;
        const int CASEINFO = 1, CASESCORE = 2, CASEENROLL = 3;
        DataTable dtInfo, dtScore, dtEnroll;
        ArrayList selectAll;
        public frmStudent(frmLogin afrmLogin = null)
        {
            myLoginForm = afrmLogin;
            InitializeComponent();
        }

        private void frmStudent_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (myLoginForm != null)
            {
                myLoginForm.Close();
            }
        }

        void freshTable(int cas)
        {
            string selectStr = (string)selectAll[cas];
            switch (cas)
            {
                case CASEINFO:
                    dtInfo.Clear();
                    Data.fillDataTable(selectStr, dtInfo);
                    dgvInfo.DataSource = dtInfo;
                    dgvInfo.Columns[Data.c_student_snum].HeaderText = "学号";
                    dgvInfo.Columns[Data.c_student_sname].HeaderText = "姓名";
                    dgvInfo.Columns[Data.c_student_sclass].HeaderText = "班级";
                    Data.columnAutoAdapter(dgvInfo);
                    break;
                case CASESCORE:
                    dtScore.Clear();
                    Data.fillDataTable(selectStr, dtScore);
                    dgvScore.DataSource = dtScore;
                    dgvScore.Columns[Data.c_course_cname].HeaderText = "课程名称";
                    dgvScore.Columns[Data.c_sc_score].HeaderText = "分数";
                    Data.columnAutoAdapter(dgvScore);
                    break;
                case CASEENROLL:
                    dtEnroll.Clear();
                    Data.fillDataTable(selectStr, dtEnroll);
                    dgvEnroll.DataSource = dtEnroll;
                    for (int i = 1; i < dgvEnroll.Columns.Count; ++i)
                    {
                        dgvEnroll.Columns[i].ReadOnly = true;
                    }
                    Data.columnAutoAdapter(dgvEnroll);
                    break;

                default: break;
            }
        }

        private void frmStudent_Load(object sender, System.EventArgs e)
        {

            dtInfo = new DataTable();
            dtScore = new DataTable();
            dtEnroll = new DataTable();

            string sqlStrPersonalInfo = @"select * from {0} where {1}='{2}'";
            sqlStrPersonalInfo = string.Format(sqlStrPersonalInfo, Data.t_student, Data.c_student_snum, Data.loginID);

            string sc_cnum = Data.t_sc + "." + Data.c_sc_cnum;
            string course_cnum = Data.t_course + "." + Data.c_course_cnum;

            string sqlStrSelectedCourse = @"select {0},{1} from {2},{3} where {4}='{5}' and {6}={7}";
            sqlStrSelectedCourse = string.Format(sqlStrSelectedCourse,
                Data.c_course_cname, Data.c_sc_score,
                Data.t_sc, Data.t_course,
                Data.c_sc_snum, Data.loginID,
                sc_cnum, course_cnum
                );

            string sqlStrToBeSelectedCourse = @"select * from {0} B where B.{1} not in ( select A.{2} from {3} A where A.{4} = '{5}' )";
            sqlStrToBeSelectedCourse = string.Format(sqlStrToBeSelectedCourse, Data.t_course, Data.c_course_cnum, Data.c_sc_cnum, Data.t_sc, Data.c_sc_snum, Data.loginID);

            selectAll = new ArrayList();
            selectAll.Add("");
            selectAll.Add(sqlStrPersonalInfo);
            selectAll.Add(sqlStrSelectedCourse);
            selectAll.Add(sqlStrToBeSelectedCourse);


            freshTable(CASEINFO);
            freshTable(CASESCORE);


            string sqlStr = @"select * from {0}";
            sqlStr = string.Format(sqlStr, Data.t_enroll);

            DataTable dt = new DataTable();
            Data.fillDataTable(sqlStr, dt);

            if (dt.Rows[0][0].ToString().Equals("True"))
            {
                DataGridViewCheckBoxColumn dc = new DataGridViewCheckBoxColumn();
                dc.Name = "colSelect";
                dgvEnroll.Columns.Add(dc);
                freshTable(CASEENROLL);
            }
            else
            {
                tabControl1.TabPages.Remove(tabPage3);
            }

        }

        private void btnAdd_Click(object sender, System.EventArgs e)
        {

            for (int i = 0; i < dgvEnroll.Rows.Count; ++i)
            {
                if (dgvEnroll.Rows[i].Cells["colSelect"].EditedFormattedValue.ToString() == "True")
                {
                    string sqlStr = @"insert into {0} values('{1}', '{2}', NULL)";
                    sqlStr = string.Format(sqlStr, Data.t_sc, Data.loginID, dgvEnroll.Rows[i].Cells[Data.c_sc_cnum].Value.ToString());

                    SqlConnection con = new SqlConnection(Data.connectionString);
                    con.Open();
                    SqlCommand cmd = new SqlCommand(sqlStr, con);
                    cmd.ExecuteNonQuery();
                    con.Close();
                    MessageBox.Show("选课成功!");
                }
            }
        }

        private void button2_Click(object sender, System.EventArgs e)
        {
            freshTable(CASEENROLL);
        }

        private void button1_Click(object sender, System.EventArgs e)
        {
            freshTable(CASESCORE);
        }
    }
}

源代码文件下载地址