form1.cs

本程序可以作为数据库入门的一个小程序

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 TEN
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        //【加载】按钮，将数据库中的数据加载到窗体上的文本框中
        private void button1_Click(object sender, EventArgs e)
        {
            /* this.txtSNo.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.dataSet11, "Student.SNo"));//将表中数据绑定到相应文本框
             this.txtFName.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.dataSet11, "Student.FirstName"));
             this.txtLName.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.dataSet11, "Student.LastName"));
             this.txtScore.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.dataSet11, "Student.Score"));*/
            sqlDataAdapter1.Fill(dataSet11, "Student");

        }
        //【第一个】按钮

        private void btnmf_Click(object sender, EventArgs e)
        {
            this.BindingContext[dataSet11, "Student"].Position = 0; //移动到第一个记录

        }

        //【前一个】按钮
        private void btnmp_Click(object sender, EventArgs e)
        {
            this.BindingContext[dataSet11, "Student"].Position -= 1;  // 移动到前一个记录
        }
        //【下一个】按钮

        private void btnmn_Click(object sender, EventArgs e)
        {
            this.BindingContext[dataSet11, "Student"].Position += 1; //移动到下一个记录

        }

        //【最后一个】按钮

        private void btnml_Click(object sender, EventArgs e)
        {
            this.BindingContext[dataSet11, "Student"].Position = this.BindingContext[dataSet11, "Student"].Count - 1; //移动到最后一个记录
        }


        //【删除】按钮
        //删除一个已存在的记录
        private void btnDelete_Click(object sender, EventArgs e)
        {
            if (MessageBox.Show("你想删除记录吗？", "删除", System.Windows.Forms.MessageBoxButtons.YesNo, System.Windows.Forms.MessageBoxIcon.Warning) == DialogResult.Yes)
            {
                DataRow dr;// 删除一个已存在的记录
                int vSNo = Int32.Parse(txtSNo.Text);
                dr = dataSet11.Tables["Student"].Rows.Find(vSNo);
                dr.Delete();
            }
            try
            { sqlDataAdapter1.Update(dataSet11, "Student"); }//更新表
            catch (Exception ex)
            { MessageBox.Show(ex.Message); }

        }


        //{添加】按钮：把文本框清空，以便输入新数据，并使【更新】按钮可见。
        private void btnAdd_Click(object sender, EventArgs e)
        {
            btnAdd.Visible = false;
            btnEdit.Visible = false;
            btnDelete.Enabled = false;
            btnClose.Enabled = false;
            btnmf.Enabled = false;
            btnml.Enabled = false;
            btnmn.Enabled = false;
            btnmp.Enabled = false;
            btnUpdate.Visible = true;
            btnCancel.Visible = true;
            /*   SqlConnection conn = new SqlConnection("server=56907a770758413;database=student;uid=sa;pwd=123;");
               conn.Open();
               SqlCommand cmd = new SqlCommand();

               cmd.CommandText = "insert into student values('" + this.txtSNo.Text + "','" + this.txtFName.Text + "'"; 
                 cmd.Connection=conn; 
                      cmd.ExecuteNonQuery(); 
                    //下面是查询数据用的 
                    SqlDataAdapter sda = new SqlDataAdapter("select *from student", conn); 
                      DataSet dataSet11=new DataSet(); 
                   sda.Fill(dataSet11,"student"); 
                       conn.Close(); */


            //  int vSNo = Int32.Parse(txtSNo.Text); //编辑一个已存在的记录


            txtSNo.Text = "";
            txtFName.Text = "";
            txtLName.Text = "";
            txtScore.Text = "";
            txtSNo.Focus();
            btnUpdate.Text = "插入有效";
             //AddUpdate = true;
            /* DataRow drAdd;
             int vSNo = Int32.Parse(txtSNo.Text);
             drAdd = dataSet11.Tables["Student"].Rows.Find(vSNo);
           
             int vScore = Int32.Parse(txtScore.Text);
            
                // drAdd = dataSet11.Tables["Student"].Rows.Find(vSNo);
            
          
             drAdd = dataSet11.Tables["Student"].NewRow();

                 drAdd[0] = vSNo;
                 drAdd[1] = txtFName.Text;
                 drAdd[2] = txtLName.Text;
                 drAdd[3] = vScore;*/
            //
            /* DataRow drAdd;
              drAdd = dataSet11.Tables["Student"].NewRow();

              drAdd["SNo"] = "9";
              drAdd["FirstName"] = "李";
              drAdd["LastName"] = "里";
              drAdd["Score"] = "99";*/

            /*    DataRow drAdd;
                drAdd = dataSet11.Tables["Student"].NewRow();



                    dataSet11.Tables["Student"].Rows.Add(drAdd);
              
                    sqlDataAdapter1.Update(dataSet11, "Student");

                  //  dataSet11.Tables["Student"].AcceptChanges();
            
             /*   catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }*/


        }


        //  【编辑】按钮：把光标指向txtSNo文本框，并且在数据库表Student中找到要更新的相应“学号”。
        private  void btnEdit_Click(object sender, EventArgs e)
        {

            btnAdd.Visible = false;
            btnEdit.Visible = false;
            btnDelete.Enabled = false;
            btnClose.Enabled = false;
            btnmf.Enabled = false;
            btnml.Enabled = false;
            btnmn.Enabled = false;
            btnmp.Enabled = false;
            btnUpdate.Visible = true;
            btnCancel.Visible = true;
            // int i = BindingContext[dataSet11, "Student"].Position;
            // int vSNo = Int32.Parse(txtSNo.Text); //编辑一个已存在的记录
            txtSNo.Focus();

         //AddUpdate = false;
            //DataRow drUpdate = dataSet11.Tables["Student"].Rows.Find(vSNo);
            // drUpdate = dataSet11.Tables["Student"].NewRow();
            /*    drUpdate.BeginEdit();
                drUpdate["SNo"] = Int32.Parse(txtSNo.Text);
                drUpdate["FirstName"] = txtFName.Text;
                drUpdate["LastName"] = txtLName.Text;
                drUpdate["Score"] = Int32.Parse(txtScore.Text);
                  
               // dataSet11.Tables["Student"].Rows[i].Delete();
                  //dataSet11.Tables["Student"].Rows.Add(drUpdate);
                  drUpdate.EndEdit();
                sqlDataAdapter1.Update(dataSet11, "Student");
               // dataSet11.Tables["Student"].AcceptChanges();
    //   txtSNo.Focus();//把光标指向txtSNo文本框
       //AddUpdate = false;*/
            //在数据库表Student中找到要更新相应"学号"

        }



        //【更新】按钮：当用户单击【编辑】或【添加】按钮时有效。
        private void btnUpdate_Click(object sender, EventArgs e)
        {
         
            //bool AddUpdate;
            if ( btnUpdate.Text =="插入有效")
            {
                try
                {
                    int vSNo = Int32.Parse(txtSNo.Text); //添加一个新记录
                    int vScore = Int32.Parse(txtScore.Text);
                    DataRow drAdd;
                    drAdd = dataSet11.Tables["Student"].NewRow();
                    
                    drAdd["SNo"] = vSNo;
                    drAdd["FirstName"] = txtFName.Text;
                    drAdd["LastName"] = txtLName.Text;
                    drAdd["Score"] = vScore;
                   ;
                    dataSet11.Tables["Student"].Rows.Add(drAdd);
                    sqlDataAdapter1.Update(dataSet11, "Student");
                    sqlDataAdapter1.Fill(dataSet11, "Student");
                    MessageBox.Show("添加成功", "提示");
                }
                catch (Exception ex)
                { MessageBox.Show(ex.Message); }
            }

            else
            {
                try
                {
                    int vSNo = Int32.Parse(txtSNo.Text); //编辑一个已存在的记录
                    int vScore = Int32.Parse(txtScore.Text);
                    DataRow drUpdate;
                    drUpdate = dataSet11.Tables["Student"].Rows.Find(Int32.Parse(txtSNo.Text));
                    drUpdate.BeginEdit();
                    drUpdate["SNo"] = vSNo;
                    drUpdate["FirstName"] = txtFName.Text;
                    drUpdate["LastName"] = txtLName.Text;
                    drUpdate["Score"] = vScore;
                    drUpdate.EndEdit();

                    sqlDataAdapter1.Update(dataSet11, "Student");
                    MessageBox.Show("编辑成功", "提示");
                }
                catch (Exception ex)
                { MessageBox.Show(ex.Message); }

            }
        }


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





        private void btnCancel_Click(object sender, EventArgs e)
        {
            btnUpdate.Text ="更新";
            btnAdd.Visible = true;
            btnEdit.Visible = true;
            btnDelete.Enabled = true;
            btnClose.Enabled = true;
            btnmf.Enabled = true;
            btnml.Enabled = true;
            btnmn.Enabled = true;
            btnmp.Enabled = true;
            btnUpdate.Visible = false;
            btnCancel.Visible = false;
            //this.Close();
        }

       












    }
}