public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            //窗体加载事件

            dataGridView1.DataSource = getData2();

            DataTable table = getData2();

            textBox1.Text = DataTableToJson(getData2()) + "\r\n";

            textBox1.Text += DataTableToJson(table) + "\r\n";

        }

        #region 获得 DataTable数据

        public DataTable getData1()

        {

            DataTable dt = new DataTable();

            dt.Columns.Add("编号", typeof(Int32));

            dt.Columns.Add("姓名", typeof(string));

            dt.Columns.Add("性别", typeof(string));

            dt.Columns.Add("学历", typeof(string));

            dt.Rows.Add(, "王超", "男", "本科");

            dt.Rows.Add(, "周丽", "女", "专科");

            dt.Rows.Add(, "李娟", "女", "专科");

            dt.Rows.Add(, "杨明", "男", "硕士");

            dt.Rows.Add(, "张德", "男", "本科");

            return dt;

        }

        public DataTable getData2()

        {

            DataTable dt = new DataTable("Student");

            dt.Columns.Add("StudentId", typeof(Int32));

            dt.Columns.Add("StudentName", typeof(string));

            dt.Columns.Add("Address", typeof(string));

            dt.Columns.Add("MobileNo", typeof(string));

            //Data

            dt.Rows.Add(, "Manish", "Hyderabad", "");

            dt.Rows.Add(, "Venkat", "Hyderabad", "");

            dt.Rows.Add(, "Namit", "Pune", "");

            dt.Rows.Add(, "Abhinav", "Bhagalpur", "");

            return dt;

        }

        #endregion

        #region 从DataTable数据转为List

        public List<Student> StudentList()

        {

            DataTable dt = new DataTable();

            dt = getData2();

            List<Student> studentList = new List<Student>();

            for (int i = ; i < dt.Rows.Count; i++)

            {

                Student student = new Student();

                student.StudentId = Convert.ToInt32(dt.Rows[i]["StudentId"]);

                student.StudentName = dt.Rows[i]["StudentName"].ToString();

                student.Address = dt.Rows[i]["Address"].ToString();

                student.MobileNo = dt.Rows[i]["MobileNo"].ToString();

                studentList.Add(student);

            }

            return studentList;

        }

        #endregion

        #region 从DataTable数据 转为 Json

        public string DataTableToJson(DataTable table)

        {

            var JsonString = new StringBuilder();

            if (table.Rows.Count > )

            {

                JsonString.Append("[");

                for (int i = ; i < table.Rows.Count; i++)

                {

                    JsonString.Append("{");

                    for (int j = ; j < table.Columns.Count; j++)

                    {

                        if (j < table.Columns.Count - )

                        {

                            JsonString.Append("\"" + table.Columns[j].ColumnName.ToString() + "\":" + "\"" + table.Rows[i][j].ToString() + "\",");

                        }

                        else if (j == table.Columns.Count - )

                        {

                            JsonString.Append("\"" + table.Columns[j].ColumnName.ToString() + "\":" + "\"" + table.Rows[i][j].ToString() + "\"");

                        }

                    }

                    if (i == table.Rows.Count - )

                    {

                        JsonString.Append("}");

                    }

                    else

                    {

                        JsonString.Append("},");

                    }

                }

                JsonString.Append("]");

            }

            return JsonString.ToString();

        }

        #endregion

    }

    #region 实体类

    public class Student

    {

        public int StudentId { get; set; }

        public string StudentName { get; set; }

        public string Address { get; set; }

        public string MobileNo { get; set; }

    }

    #endregion

创建datatable   

dt = new DataTable();
dt.Columns.Add("a");
dt.Columns.Add("b");
dt.Rows.Add(1);
object[] iis = new object[2];
iis[0] = 1;
iis[1] = 2;
dt.Rows.Add(iis);
DataSource = dt;

private void button3_Click(object sender, EventArgs e)

        {

            //创建一个空表

            DataTable dt = new DataTable();

            dt.Columns.Add("列1");

            dt.Columns.Add("列2");

            dt.Columns.Add("列3");

            dt.Columns.Add("列4");

            for (int i=;

                i<;i++)

            {

                DataRow dr = dt.NewRow();

                dt.Rows.Add(dr);

                dt.Rows[]["列1"] = "第一列数据";//通过名称赋值

                dt.Rows[]["列2"] = "第二列数据";//通过名称赋值

                dt.Rows[]["列3"] = "第三列数据";//通过名称赋值

                dt.Rows[]["列4"] = "第四列数据";//通过名称赋值

            }       

        }

  dt = dal字典.SelectBy字典类型("产品类型");

                //产品类型.SelectedIndex = -1;

                DataRow dr = dt.NewRow();

                dr["字典类型"] = "产品类型";

                dr["字典值"] = "";

                //dt.Rows.Add(dr);

                dt.Rows.InsertAt(dr, );