string qymc = textBox1.Text.ToString();  //获取文本框要模糊查询的文字

    using (SQLiteConnection con = new SQLiteConnection(DATASOURCE))

    {

        con.Open();

        using (SQLiteCommand cmd = new SQLiteCommand())

        {

            cmd.Connection = con;

            cmd.CommandText = string.Format(@"select * from test t ");　　//datagridview要显示的数据

            int rows = cmd.ExecuteNonQuery();

            SQLiteDataAdapter sda = new SQLiteDataAdapter(cmd);

            DataSet ds = new DataSet();

            sda.Fill(ds);

            DataTable dtbl = ds.Tables[];

            DataView dv = dtbl.DefaultView;

            dv.RowFilter = " name like '%"+qymc+"%' ";　　//相当于接着上面的sql语句的where子句

            dataGridView1.DataSource = dv;

        }

    }