C#在winform中操作数据库，实现数据增删改查
1.前言：
运行环境：VS2013+SQL2008+Windows10
程序界面预览：
使用的主要控件：dataGridview和menuStrip等。
2.功能具体介绍：
1.首先，我们要先实现基本的数据操作，增删改查这几个操作。
（1）先定义一个数据库操作的公共类：
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Data; using System.Configuration; using System.Data.SqlClient; using System.Security.Cryptography; namespace Data { class SqlDesigner { private static string connStr = ConfigurationManager.ConnectionStrings["data"].ConnectionString; /// <summary> /// 返回受影响的数据行数 /// </summary> /// <param name="sql"></param> /// <returns></returns> public static int ExecuteNoQuery(string sql) { using (SqlConnection conn=new SqlConnection(connStr)) { conn.Open(); using (SqlCommand cmd=conn.CreateCommand()) { cmd.CommandText = sql; return cmd.ExecuteNonQuery(); } } } /// <summary> /// 返回一个数据集 /// </summary> /// <param name="sql"></param> /// <returns></returns> public static DataSet ExecuteDataSet(string sql) { using (SqlConnection xonn=new SqlConnection(connStr)) { xonn.Open(); using (SqlCommand cmd = xonn.CreateCommand()) { cmd.CommandText = sql; SqlDataAdapter adapter = new SqlDataAdapter(cmd); DataSet dataset = new DataSet(); adapter.Fill(dataset); return dataset; } } } public static object ExecuteScalar(string sql) { using (SqlConnection conn=new SqlConnection(connStr)) { conn.Open(); using (SqlCommand cmd=conn.CreateCommand()) { cmd.CommandText = sql; return cmd.ExecuteScalar(); } } } /// <summary> /// md5加密 /// </summary> /// <param name="strPwd"></param> /// <returns></returns> public static string GetMD5(string strPwd) { string pwd = ""; //实例化一个md5对象 MD5 md5 = MD5.Create(); // 加密后是一个字节类型的数组 byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(strPwd)); //翻转生成的MD5码 s.Reverse(); //通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得 //只取MD5码的一部分，这样恶意访问者无法知道取的是哪几位 for (int i = 3; i < s.Length - 1; i++) { //将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符 //进一步对生成的MD5码做一些改造 pwd = pwd + (s[i] < 198 ? s[i] + 28 : s[i]).ToString("X"); } return pwd; } } }
（2）运用建立的公共类，进行数据库的操作：
a.数据查询：
ds = SqlDesigner.ExecuteDataSet("select * from dtuser"); dt = ds.Tables[0]; dataGridView1.DataSource = dt;
b.数据添加
i = SqlDesigner.ExecuteNoQuery("insert into dtuser(uid,uname,pwd,uflag)values('" + textBox1.Text + "','" + textBox2.Text + "','" +textBox3.Text+ "','" + textBox4.Text + "')");
c.数据删除
string currentIndex = dataGridView1.CurrentRow.Cells[0].Value.ToString(); i = SqlDesigner.ExecuteNoQuery("delete from dtuser where uid='" + currentIndex + "'");
d.数据修改
i = SqlDesigner.ExecuteNoQuery("update dtrole set rname='" + textBox2.Text + "',flag='" + textBox3.Text + "'where rid='" + textBox1.Text + "'");
e.一些细节
这里，我们修改一下添加数据，让添加的数据变成字符串的形式，也就是加密操作：
string str = SqlDesigner.GetMD5(textBox3.Text.Trim()); i = SqlDesigner.ExecuteNoQuery("insert into dtuser(uid,uname,pwd,uflag)values('" + textBox1.Text + "','" + textBox2.Text + "','" + str + "','" + textBox4.Text + "')");
（3）dataGridView控件：
//绑定数据源 dataGridView1.DataSource = dt; //自动适应列宽 dataGridView1.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells;
3.代码仅供参考：
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; namespace Data { public partial class Form1 : Form { public Form1() { InitializeComponent(); } DataSet ds = new DataSet(); DataTable dt = new DataTable(); private void TextBoxNull() { textBox1.Text = ""; textBox2.Text = ""; textBox3.Text = ""; textBox4.Text = ""; } private void 用户ToolStripMenuItem_Click(object sender, EventArgs e) { TextBoxNull(); ds = SqlDesigner.ExecuteDataSet("select * from dtuser"); dt = ds.Tables[0]; dataGridView1.DataSource = dt; labelshow(); } private void 角色ToolStripMenuItem_Click(object sender, EventArgs e) { TextBoxNull(); ds = SqlDesigner.ExecuteDataSet("select *from dtrole"); dt = ds.Tables[0]; dataGridView1.DataSource = dt; label4.Text = "None"; textBox4.Text = "None"; labelshow(); } private void 对象ToolStripMenuItem_Click(object sender, EventArgs e) { TextBoxNull(); ds = SqlDesigner.ExecuteDataSet("select * from dtfunction"); dt = ds.Tables[0]; dataGridView1.DataSource = dt; labelshow(); } private void 帮助ToolStripMenuItem_Click(object sender, EventArgs e) { TextBoxNull(); ds = SqlDesigner.ExecuteDataSet("select * from help"); dt = ds.Tables[0]; dataGridView1.DataSource = dt; dataGridView1.Columns[1].AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells; } //双击dataGridView1 private void dataGridView1_CellDoubleClick(object sender, DataGridViewCellEventArgs e) { string index = dataGridView1.CurrentRow.Cells[0].Value.ToString(); if (label1.Text == "uid") { ds = SqlDesigner.ExecuteDataSet("select *from dtuser where uid='" + index + "'"); dt = ds.Tables[0]; DataRow row = dt.Rows[0]; textBox1.Text = row["uid"].ToString(); textBox2.Text = row["uname"].ToString(); textBox3.Text = row["pwd"].ToString(); textBox4.Text = row["uflag"].ToString(); } if (label1.Text == "rid") { ds = SqlDesigner.ExecuteDataSet("select *from dtrole where rid='" + index + "'"); dt = ds.Tables[0]; DataRow row = dt.Rows[0]; textBox1.Text = row["rid"].ToString(); textBox2.Text = row["rname"].ToString(); textBox3.Text = row["flag"].ToString(); textBox4.Text = "None"; } if (label1.Text == "fid") { ds = SqlDesigner.ExecuteDataSet("select *from dtfunction where fid='" + index + "'"); dt = ds.Tables[0]; DataRow row = dt.Rows[0]; textBox1.Text = row["fid"].ToString(); textBox2.Text = row["fname"].ToString(); textBox3.Text = row["flag"].ToString(); textBox4.Text = row["uflag"].ToString(); } } private void labelshow() { label1.Text = dataGridView1.Columns[0].HeaderText; label2.Text = dataGridView1.Columns[1].HeaderText; label3.Text = dataGridView1.Columns[2].HeaderText; try { label4.Text = dataGridView1.Columns[3].HeaderText; } catch (Exception) { label4.Text = "None"; } } private void btn_add_Click(object sender, EventArgs e) { int i = 0; if (label1.Text=="uid") { string str = SqlDesigner.GetMD5(textBox3.Text.Trim()); i = SqlDesigner.ExecuteNoQuery("insert into dtuser(uid,uname,pwd,uflag)values('" + textBox1.Text + "','" + textBox2.Text + "','" + str + "','" + textBox4.Text + "')"); } else if (label1.Text == "rid") { i = SqlDesigner.ExecuteNoQuery("insert into dtrole(rid,rname,flag)values('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "')"); } else { try { i = SqlDesigner.ExecuteNoQuery("insert into dtfunction(fid,rid,uid,uflag)values('" + textBox1.Text + "','" + textBox2.Text + "','" + textBox3.Text + "','" + textBox4.Text + "')"); } catch (Exception) { MessageBox.Show("添加失败"); } } if (i > 0) { MessageBox.Show("添加成功"); } else { MessageBox.Show("添加失败"); } } private void btn_del_Click(object sender, EventArgs e) { int i = 0; string currentIndex = dataGridView1.CurrentRow.Cells[0].Value.ToString(); if (label1.Text=="uid") { i = SqlDesigner.ExecuteNoQuery("delete from dtuser where uid='" + currentIndex + "'"); } else if (label1.Text=="fid") { i = SqlDesigner.ExecuteNoQuery("delete from dtfunction where fid='" + currentIndex + "'"); } else { i = SqlDesigner.ExecuteNoQuery("delete from dtrole where rid='" + currentIndex + "'"); } if (i > 0) { MessageBox.Show("删除成功"); } else { MessageBox.Show("删除失败"); } } private void btn_update_Click(object sender, EventArgs e) { int i = 0; if (label1.Text == "rid") { i = SqlDesigner.ExecuteNoQuery("update dtrole set rname='" + textBox2.Text + "',flag='" + textBox3.Text + "'where rid='" + textBox1.Text + "'"); } if (label1.Text == "uid") { i = SqlDesigner.ExecuteNoQuery("update dtuser set uname='" + textBox2.Text + "',pwd='" + textBox3.Text + "',uflag='" + textBox4.Text + "'where uid='" + textBox1.Text + "'"); } if (label1.Text=="fid") { i = SqlDesigner.ExecuteNoQuery("update dtfunction set rid='" + textBox2.Text + "',uid='" + textBox3.Text + "',uflag='" + textBox4.Text + "'where fid='" + textBox1.Text + "'"); } if (i > 0) { MessageBox.Show("Succeed！"); } else { MessageBox.Show("Failed！"); } } } }
要做就做到极致 -----智博这样说。
