1         private void button1_Click(object sender, EventArgs e)
 2         {
 3             StringBuilder sbSql = new StringBuilder("select * from student ");
 4             List<string> wheres = new List<string>();
 5             List<SqlParameter> parameters = new List<SqlParameter>();
 6             foreach (Control ct in panel1.Controls) //遍历容器中的集合
 7             {
 8                 //这里只介绍一种思维方式，具体逻辑还需改造方法
 9                 if (ct is TextBox) //文本框
10                 {
11                     wheres.Add(" "+ct.Name+" like @"+ct.Name+" "); //ct.Name：获取控件的Name属性，必须有命名规则，和数据库字段相同
12                     parameters.Add(new SqlParameter("@"+ct.Name+"","‘%"+ct.Text.Trim()+"%‘"));
13                     continue;
14                 }
15                 if (ct is CheckBox)
16                 {
17                     //复选框
18                 }
19                 if (ct is DateTimePicker)
20                 {
21                     //日期控件
22                 }
23                 if (ct is ComboBox)
24                 {
25                     //下拉框
26                 }
27             }
28             //开始多条件搜索拼接
29             if (wheres.Count>0) //有值
30             {
31                 sbSql.Append(" where ");
32                 sbSql.Append(string.Join(" and ",wheres.ToArray())); //调用字符串连接 string.Join
33             }
34             MessageBox.Show(sbSql.ToString()); //多条件拼接SQL成功！
35         }