thesis.cs

来自「系统简介： 本系统是一个用于管理学生毕业系统的简单系统。系统包含的信息包括学生」· CS 代码 · 共 218 行

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace graduationNET
{
    public partial class thesis : Form
    {
        SqlConnection myconnection;

        SqlDataAdapter sa;

        SqlCommand sqlcmd;

        DataSet ds;

        private void GetData()
        {
            string constr = "Data Source=localhost;Initial Catalog=.NET_51671;Integrated Security= true;";
            myconnection = new SqlConnection(constr);

            sa = new SqlDataAdapter();

            sqlcmd = new SqlCommand();
            sqlcmd.CommandText = "select * from papers_51671 ";
            sqlcmd.Connection = myconnection;

            sa.SelectCommand = sqlcmd;

            ds = new DataSet();

            sa.Fill(ds, "papers_51671");

            dataGridView1.DataSource = ds.Tables["papers_51671"];
            dataGridView1.CurrentCell = this.dataGridView1[0, 0];

            showdata();
        }

        private void showdata()
        {
            string sqlstatement = "select * from papers_51671 where sno=@sno";
            sqlcmd = new SqlCommand(sqlstatement, myconnection);

            string selectedsno = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0].Value.ToString();

            sqlcmd.Parameters.AddWithValue("@sno", selectedsno);

            SqlDataReader sr;

            try
            {
                myconnection.Open();
                sr = sqlcmd.ExecuteReader();
                while (sr.Read())
                {
                    snotxt.Text = sr[0].ToString();
                    subtxt.Text = sr[1].ToString();
                    teatxt.Text = sr[2].ToString();
                    gradetxt.Text = sr[3].ToString();
                }
            }
            catch (SqlException ex)
            {
                MessageBox.Show("数据读取失败：" + ex.Message, "出现错误",
                   MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                myconnection.Close();
            }
        }
        public thesis()
        {
            InitializeComponent();
            GetData();
        }

        private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            showdata();
        }

        private void newbtn_Click(object sender, EventArgs e)
        {
            snotxt.Text = "";
            subtxt.Text = "";
            teatxt.Text = "";
            gradetxt.Text = "";
        }

        private void savebtn_Click(object sender, EventArgs e)
        {
            //  定义sql语句
            string sqlstatement;
            sqlstatement = @"insert into papers_51671 values(@sno,@sub,@tea,@grade)";

            sqlcmd = new SqlCommand(sqlstatement, myconnection);

            sqlcmd.Parameters.AddWithValue("@sno", snotxt.Text);
            sqlcmd.Parameters.AddWithValue("@sub", subtxt.Text);
            sqlcmd.Parameters.AddWithValue("@tea", teatxt.Text);
            sqlcmd.Parameters.AddWithValue("@grade", gradetxt.Text);

            //打开连接
            myconnection.Open();

            //执行sql语句
            try
            {
                int rowaffected = sqlcmd.ExecuteNonQuery();
                if (rowaffected == 1)
                {
                    MessageBox.Show("保存成功！", "信息提示",
                        MessageBoxButtons.OK, MessageBoxIcon.Information);

                    GetData();
                }

            }
            catch (SqlException ex)
            {
                MessageBox.Show("保存错误：" + ex.Message, "出现错误",
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
            }

            finally
            {
                myconnection.Close();
            }
        }

        private void deletebtn_Click(object sender, EventArgs e)
        {
            string sqlstatement = "Delete from papers_51671 where sno=@sno";

            sqlcmd = new SqlCommand(sqlstatement, myconnection);

            dataGridView1.Rows[0].Selected = true;
            string selectedstore = dataGridView1.Rows[dataGridView1.CurrentRow.Index].Cells[0].Value.ToString();

            sqlcmd.Parameters.AddWithValue("@sno", selectedstore);

            myconnection.Open();

            try
            {
                int rowaffected = sqlcmd.ExecuteNonQuery();
                if (rowaffected == 1)
                {
                    MessageBox.Show("删除成功！", "信息提示",
                       MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                GetData();
            }
            catch (SqlException ex)
            {
                MessageBox.Show("删除错误：" + ex.Message, "出现错误",
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                myconnection.Close();
            }
        }

        private void updatebtn_Click(object sender, EventArgs e)
        {
            string sqlstatement = "update papers_51671 set subject=@sub,teacher=@tea,grade=@grade ";
            sqlstatement += "where sno=@sno ";

            sqlcmd = new SqlCommand(sqlstatement, myconnection);

            sqlcmd.Parameters.AddWithValue("@sno", snotxt.Text);
            sqlcmd.Parameters.AddWithValue("@sub", subtxt.Text);
            sqlcmd.Parameters.AddWithValue("@tea", teatxt.Text);
            sqlcmd.Parameters.AddWithValue("@grade", gradetxt.Text);

            try
            {
                myconnection.Open();
                int rowafftected = sqlcmd.ExecuteNonQuery();
                if (rowafftected == 1)
                {
                    MessageBox.Show("更新成功！", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

                    GetData();
                }
            }
            catch (SqlException ex)
            {
                MessageBox.Show("更新出错：" + ex.Message, "出现错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            finally
            {
                myconnection.Close();
            }
        }

        private void thesis_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“___NET_51671DataSet.papers_51671”中。您可以根据需要移动或移除它。
            this.papers_51671TableAdapter.Fill(this.___NET_51671DataSet.papers_51671);

        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Close();
        }

    }
}