C#_会员管理系统：开发六（数据搜索）

增加界面中的搜索功能

会员资料管理界面(VIPManager.cs):

详细代码如下：

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

 namespace 会员管理系统
 {
     public partial class VIPManager : Form
     {
         public VIPManager()
         {
             InitializeComponent();
         }

         //连接字符串 获取配置文件里的连接路径,多次需要调用，放在外面方便
         static string connStr = ConfigurationManager.ConnectionStrings["str"].ConnectionString;
         //窗体运行自动加载
         private void VipManager_Load(object sender, EventArgs e)
         {
             //刷新数据
             Refresh();
             cmbforfieldSelecting.Text = "全局搜索";
             cmbforfieldSelecting.Items.Add("全局搜索");
             cmbforfieldSelecting.Items.Add("编号");
             cmbforfieldSelecting.Items.Add("名字");
             cmbforfieldSelecting.Items.Add("性别");
             cmbforfieldSelecting.Items.Add("年龄");
             cmbforfieldSelecting.Items.Add("地址");
             cmbforfieldSelecting.Items.Add("电话");
         }

         //写一个刷新数据的方法(跟查看数据一样)
         public void Refresh(bool isAdded = false)
         {
             //查询数据库字符串
             string sql = String.Format("select vId '{0}',vName '{1}',vGender '{2}',vAge '{3}',vAddress '{4}',vPhone '{5}' from VipInformation", "编号", "名字", "性别", "年龄", "地址", "电话");
             //连接数据库对象
             SqlConnection conn = new SqlConnection(connStr);
             //操作数据库对象
             SqlCommand cmd = new SqlCommand(sql, conn);
             //创建表对象
             System.Data.DataTable dt = new System.Data.DataTable();
             //创建数据库填充操作对象(语句)
             SqlDataAdapter sda = new SqlDataAdapter(cmd);
             //把数据填充进dt表中
             sda.Fill(dt);
             //指定dgvManager控件的数据源:dt
             dgvManager.DataSource = dt;

             //if (isAdded)
             //{
             //    if (dt.Rows.Count > 0)
             //        dgvManager.Rows[0].Selected = false;
             //    dgvManager.Rows[dt.Rows.Count - 1].Selected = true;
             //}
         }

         //刷新数据界面
         private void btnView_Click(object sender, EventArgs e)
         {
             //刷新数据
             Refresh();
         }

         //添加数据
         private void btnAdd_Click(object sender, EventArgs e)
         {
             //判断文本框是否为空，提示数据完整性
             if (txtName.Text == "" || txtGender.Text == "" || txtAge.Text == "" || txtAddress.Text == "" || txtPhone.Text == "")
             {
                 MessageBox.Show("数据不能为空，请填写齐全");
                 return;
             }
             //插入数据库字符串
             string sql = string.Format("insert into VipInformation values('{0}','{1}',{2},'{3}','{4}')",txtName.Text.Trim(),txtGender.Text.Trim(),txtAge.Text.Trim(),txtAddress.Text.Trim(),txtPhone.Text.Trim());
             //连接数据库对象
             SqlConnection conn = new SqlConnection(connStr);
             //操作数据库对象
             SqlCommand cmd = new SqlCommand(sql, conn);
             //创建表对象
             System.Data.DataTable dt = new DataTable();
             //创建数据库填充操作对象(语句)
             SqlDataAdapter sda = new SqlDataAdapter(cmd);
             //把数据填充进dt表中
             sda.Fill(dt);
             //指定dgvManager控件的数据源:dt
             dgvManager.DataSource = dt;
             //刷新数据
             Refresh();
         }

         //删除数据
         private void btnDelete_Click(object sender, EventArgs e)
         {
             //使用sql删除语句,where 1=1 就是没有条件，等于全部数据删除
             string sql = "delete from VipInformation where 1=1";
             //如果选中某行则执行
             if (dgvManager.CurrentRow.Selected)
             {
                 sql = sql + " and vid=" + Convert.ToInt32(dgvManager.CurrentRow.Cells[].Value.ToString());
             }
             int n = ;
             //创建连接数据库对象
             SqlConnection conn = new SqlConnection(connStr);
             //创建操作数据库对象
             SqlCommand cmd = new SqlCommand(sql, conn);
             //打开数据库
             conn.Open();
             //取得ExecuteNonQuery返回的受影响行数，无影响则为0
             n = cmd.ExecuteNonQuery();
             if (n == )
             {
                 MessageBox.Show("删除操作失败!不存在的ID");
                 conn.Close();
                 return;
             }
             else if (n > )
             {
                 MessageBox.Show("删除操作成功!");
             }
             //关闭数据库连接
             conn.Close();
             //刷新数据界面
             Refresh();
         }

         //修改数据
         private void btnSave_Click(object sender, EventArgs e)
         {
             if (txtName.Text == "" || txtGender.Text == "" || txtAge.Text == "" || txtAddress.Text == "" || txtPhone.Text == "")
             {
                 MessageBox.Show("所提供的数据不完整，请填写完整数据");
                 return;
             }
             int n = ;
             //更新SQL语句
             string sqlupdate = "update VipInformation set vName='" + txtName.Text + "',vgender='" + txtGender.Text + "',vage=" + txtAge.Text + ",vaddress='" + txtAddress.Text + "',vphone='" + txtPhone.Text + "' where vid='" + dgvManager.CurrentRow.Cells[].Value.ToString() + "'";
             SqlConnection conn = new SqlConnection(connStr);
             SqlCommand cmd = new SqlCommand(sqlupdate, conn);
             conn.Open();
             n = cmd.ExecuteNonQuery();
             if (n == )
             {
                 MessageBox.Show("修改操作失败！");
                 conn.Close();
                 return;
             }
             else if (n > )
             {
                 MessageBox.Show("修改操作成功!");
             }
             conn.Close();
             Refresh();
         }

         //点击dgvManager在文本框上显示
         private void dgvManager_CellContentClick(object sender, DataGridViewCellEventArgs e)
         {
             txtName.Text = dgvManager.CurrentRow.Cells[].Value.ToString();
             txtGender.Text = dgvManager.CurrentRow.Cells[].Value.ToString();
             txtAge.Text = dgvManager.CurrentRow.Cells[].Value.ToString();
             txtAddress.Text = dgvManager.CurrentRow.Cells[].Value.ToString();
             txtPhone.Text = dgvManager.CurrentRow.Cells[].Value.ToString();
         }

         string selectedValue;
         //事件索引改变时触发
         private void cmbforfieldSelecting_SelectedIndexChanged(object sender, EventArgs e)
         {
             string strSelected = cmbforfieldSelecting.Text;
             switch (strSelected)
             {
                 case "全局搜索":
                     selectedValue = "全局搜索";
                     break;
                 case "编号":
                     selectedValue="vid";
                     break;
                 case "名字":
                     selectedValue = "vname";
                     break;
                 case "性别":
                     selectedValue = "vgender";
                     break;
                 case "年龄":
                     selectedValue = "vage";
                     break;
                 case "地址":
                     selectedValue = "vaddress";
                     break;
                 case "电话":
                     selectedValue = "vphone";
                     break;
                 default:
                     selectedValue = "全局搜索";
                     break;
             }
         }

         private void txtDataforQuery_TextChanged(object sender, EventArgs e)
         {
             string sql = "";
             if (txtDataforQuery.Text.Trim() == "")
             {
                 //执行查询语句
                 sql = "select * from VipInformation";
             }
             else if (cmbforfieldSelecting.Text.Trim() == "全局搜索" || selectedValue == "全局搜索")
             {
                 //全字段搜索
                 sql = "select * from VipInformation where vName like '%" + txtDataforQuery.Text.Trim() + "%' or vgender like '%" + txtDataforQuery.Text.Trim() + "%' or vage like '%" + txtDataforQuery.Text.Trim() + "%' or vaddress like '%" + txtDataforQuery.Text.Trim() + "%' or vphone like '%" + txtDataforQuery.Text.Trim() + "%'";
             }
             else if (selectedValue == "vid" || selectedValue == "vname" || selectedValue == "vgender" || selectedValue == "vage" || selectedValue == "vaddress" || selectedValue == "vphone")
             {
                 //通过相应的字段进行搜索
                 sql = "select * from VipInformation where " + selectedValue + " like '%" + txtDataforQuery.Text.Trim() + "%'";
             }

             SqlConnection conn = new SqlConnection(connStr);
             SqlCommand cmd = new SqlCommand(sql, conn);
             conn.Open();
             DataTable dt = new DataTable();
             SqlDataAdapter sda = new SqlDataAdapter(cmd);
             sda.Fill(dt);
             dgvManager.DataSource = dt;
             conn.Close();
         }

         private void btnBack_Click(object sender, EventArgs e)
         {
             VIPMain vmain = new VIPMain();
             vmain.Show();
             this.Hide();
         }

         private void btnClose_Click(object sender, EventArgs e)
         {
             VIPLog vpl = new VIPLog();
             vpl.GetExitTime();
             vpl.AddMsg();
             //彻底的退出
             System.Environment.Exit();
         }

     }
 }

日志查看(VIPLog.cs)：

详细代码如下：

 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;
 using System.Configuration;

 namespace 会员管理系统
 {
     public partial class VIPLog : Form
     {
         public VIPLog()
         {
             InitializeComponent();
         }
         //连接数据库字符串多次调用，放在外面省代码量
         public static string connstr = ConfigurationManager.ConnectionStrings["str"].ToString();

         private void btnClose_Click(object sender, EventArgs e)
         {
             //获取当前时间
             GetExitTime();
             //添加当前的用户信息到日志中
             AddMsg();
             //退出程序
             System.Environment.Exit();
         }

         private void btnBack_Click(object sender, EventArgs e)
         {
             VIPMain vm = new VIPMain();
             vm.Show();
             this.Hide();
         }

         private void VIPLog_Load(object sender, EventArgs e)
         {
             //AddMsg();
             ShowMsg();
         }
         //写一个窗体加载自动从数据库获取数据并显示在datagridview的方法
         public void ShowMsg()
         {
             //连接数据库对象
             SqlConnection conn = new SqlConnection(connstr);
             string sql = "select [id] 编号,vName 名字,situation 状态,[time] 登录或退出时间,vtype 权限 from [log]";
             //操作数据库对象
             SqlCommand cmd = new SqlCommand(sql, conn);
             //创建表对象
             DataTable dt = new DataTable();
             //创建数据库填充操作对象(语句)
             SqlDataAdapter sda = new SqlDataAdapter(cmd);
             //把数据填充进dt表中
             sda.Fill(dt);
             //指定dgvManager控件的数据源:dt
             dgvLog.DataSource = dt;
         }
         //写一个窗体加载(或者退出)自动添加当前用户登录信息进数据库的方法
         public void AddMsg()
         {
             //连接数据库对象
             SqlConnection conn = new SqlConnection(connstr);

             string sql = string.Format("insert into [Log](vName,situation,time) values('{0}','{1}','{2}')",VIPLogin.uid,VIPLogin.situation,VIPLogin.time);
             //操作数据库对象
             SqlCommand cmd = new SqlCommand(sql,conn);
             //打开数据库连接
             conn.Open();
             //执行操作数据库对象并返回受影响条数
             int n = cmd.ExecuteNonQuery();
             //关闭数据库连接
             conn.Close();
         }
         //写一个获取当前系统时间的方法(退出时间)
         //退出时顺手修改登录状态
         public void GetExitTime()
         {
             VIPLogin.time = DateTime.Now;
             VIPLogin.situation = "退出";
         }

         //日志查询
         private void btnLogQuery_Click(object sender, EventArgs e)
         {
             //初始化 showSql语句
             string sql = "";
             //如果文本框txtQuery 输入的内容为空值
             if (txtLogQuery.Text.Trim() == "")
             {
                 //显示所有数据
                 sql = "select * from [log]";
             }
             else
             {
                 //否则 进行 全局搜索 将文本框里的内容与 各字段 进行 匹配
                 sql = "select * from [Log] where [id] like '%" + txtLogQuery.Text.Trim() + "%' or vname like '%" + txtLogQuery.Text.Trim() + "%' or situation like '%" + txtLogQuery.Text.Trim() + "%' or [time] like '%" + txtLogQuery.Text.Trim() + "%' or vtype like '%" + txtLogQuery.Text.Trim() + "%'";
             }
             SqlConnection conn = new SqlConnection(connstr);
             SqlCommand cmd = new SqlCommand(sql, conn);
             conn.Open();
             DataTable dt = new DataTable();
             SqlDataAdapter sda = new SqlDataAdapter(cmd);
             sda.Fill(dt);
             dgvLog.DataSource = dt;
         }

     }
 }