针对DataGridView中已进行过数据绑定，即已向DataGridView中添加了一些数据，可以结合Linq查询，并让匹配查询的行高亮显示，如下图：

　　

　　具体实现如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace Maxes_PC_Client
{
    public partial class frmWelcome : Form
   {
        private int beforeMatchedRowIndex = 0;

        public frmWelcome()
        {
            InitializeComponent();
        }

        private void frmWelcome_Load(object sender, EventArgs e)
       {
            this.dataGridViewInit();
        }

        /// <summary>
        /// DataGridView添加数据、初始化
        /// </summary>
        private void dataGridViewInit()
       {
            Dictionary<String, String> map = new Dictionary<String, String>();
            map.Add("Lily", "22");
            map.Add("Andy", "25");
            map.Add("Peter", "24");

            // 在这里必须创建一个BindIngSource对象，用该对象接收Dictionary<T, K>泛型集合的对象
            BindingSource bindingSource = new BindingSource();
            // 将泛型集合对象的值赋给BindingSourc对象的数据源
            bindingSource.DataSource = map;

            this.dataGridView.DataSource = bindingSource;
        }

        private void SearchButton_Click(object sender, EventArgs e)
        {
            if (this.KeyWord.Text.Equals(""))
           {
                return;
            }

            // Linq模糊查询
            IEnumerable<DataGridViewRow> enumerableList = this.dataGridView.Rows.Cast<DataGridViewRow>();
            List<DataGridViewRow> list = (from item in enumerableList
                                          where item.Cells[0].Value.ToString().IndexOf(this.KeyWord.Text) >= 0
                                          select item).ToList();

            // 恢复之前行的背景颜色为默认的白色背景
            this.dataGridView.Rows[beforeMatchedRowIndex].DefaultCellStyle.BackColor = System.Drawing.Color.White;

            if (list.Count > 0)
           {
                // 查找匹配行高亮显示
                int matchedRowIndex = list[0].Index;
                this.dataGridView.Rows[matchedRowIndex].DefaultCellStyle.BackColor = System.Drawing.Color.Yellow;
                this.beforeMatchedRowIndex = matchedRowIndex;
            }
        }
    }
}