数据绑定

最新推荐文章于 2024-10-21 19:59:19 发布

辉哒哒

最新推荐文章于 2024-10-21 19:59:19 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/qq_36074044/article/details/53574149

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

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        DataSet a = new DataSet();
        DBHelper b = new DBHelper();
        SqlDataAdapter c = null;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            show();
            C();
        }
        public void show()
        {
            string sql = "SELECT * FROM Grade";
            c = new SqlDataAdapter(sql, b.Connection);
            c.Fill(a, "Grade");
            DataRow row = a.Tables["Grade"].NewRow();
            row["GradeId"] = -1;
            row["GradeName"] = "全部";
            a.Tables["Grade"].Rows.InsertAt(row, 0);
            this.comboBox1.DataSource = a.Tables["Grade"];
            this.comboBox1.ValueMember = "GradeId";
            this.comboBox1.DisplayMember = "GradeName";
           
        public void C()
        {
            try
            {
                StringBuilder sql = new StringBuilder("SELECT *");
                sql.AppendLine(" FROM [Student]");
                this.dataGridView1.DataSource = a.Tables["Student"];
                if (Convert.ToInt32(this.comboBox1.SelectedValue) != -1)
                {
                    sql.AppendFormat(" WHERE [GradeId]={0}", Convert.ToInt32(this.comboBox1.SelectedValue));
                }
                sql.Append(" ORDER BY [StudentNo]");
                SqlCommand command = new SqlCommand(sql.ToString(),b.Connection);
                c.SelectCommand = command;
                this.dataGridView1.DataSource = a.Tables["Student"];
                if (a.Tables["Student"] != null)
                {
                    a.Tables["Student"].Clear();
                }
                c.Fill(a, "Student");
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            C();
        }

        private void 修改ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Form2 a = new Form2();
            a.Show();
        }
    }
}