ADO.NET编程(3)在内存中对DataTable进行增/删/改操作

　　我们可以在内存中创建DataTable对象，同样也可以对它们进行进一步的各种操作，下面的示例程序中，让我们来学习如何对它们进行基本的增删改的操作。作为示例程序的第一步我们应该是先创建一个Windows Forms的项目，然后定义一个存储和传递数据的类。

1.定义一个Employee类

　　在Employee类中定义基本的成员属性，构造函数和获取对象集合的静态方法。如下：

      /// <summary>
      /// 员工类
      /// </summary>
      public class Employee
      {
          /// <summary>
          /// 员工ID
          /// </summary>
          public Int64 ID { get; set; }
  
          /// <summary>
          /// 全名
          /// </summary>
          public string FullName { get; set; }
  
          /// <summary>
          /// 手机号
          /// </summary>
          public string PhoneNumber { get; set; }
  
          /// <summary>
          /// Email
          /// </summary>
          public string Email { get; set; }
  
          /// <summary>
          /// 无参构造函数
          /// </summary>
          public Employee() { }
  
          /// <summary>
          /// 有参构造函数
          /// </summary>
          /// <param name="id"></param>
          /// <param name="fullName"></param>
          /// <param name="phoneNumber"></param>
          /// <param name="email"></param>
          public Employee(Int64 id, string fullName, string phoneNumber, string email)
          {
              this.ID = id;
              this.FullName = fullName;
              this.PhoneNumber = phoneNumber;
              this.Email = email;
          }
  
          /// <summary>
          /// 获取员工对象集合
          /// </summary>
          /// <returns></returns>
          public static List<Employee> GetEmployeeList()
          {
              return new List<Employee>
              {
                  new Employee(id:1,fullName:"小强",phoneNumber:"18656678765",email:"xiaoqiang@126.com"),
                  new Employee(id:2,fullName:"如花",phoneNumber:"15156678765",email:"ruhua@126.com"),
                  new Employee(id:3,fullName:"玉面小飞龙",phoneNumber:"13856787665",email:"feilong@126.com"),
                  new Employee(id:4,fullName:"旺财",phoneNumber:"13497747665",email:"wancai@126.com"),
                  new Employee(id:5,fullName:"来福",phoneNumber:"13908778765",email:"laifu@126.com")
               };
          }
      } 

2.创建EmployeeManager.cs的窗体

　　界面设计很简单，一个DataGridView控件和两个Button控件，如下：

3.创建EmployeeDetail.cs窗体

　　这个窗体是用来添加、修改DataTable数据的，对应Employee类几个属性的文本框和确定、取消按钮，设计如下：

整个示例就只有这两个简单的窗体，关键代码在后面给出。

4.在内存中创建和Employee类对应的DataTable并添加数据

         /// <summary>
         /// 获取Employee表
         /// </summary>
         /// <returns></returns>
         public DataTable GetEmployeeTable()
         {
             //定义表名称
             DataTable empDt = new DataTable("Employee");
 
             //增加列
             empDt.Columns.Add("ID", typeof(Int64));
             empDt.Columns.Add("FullName", typeof(string));
             empDt.Columns.Add("PhoneNumber", typeof(string));
             empDt.Columns.Add("Email", typeof(string));
 
             //定义主键
             empDt.PrimaryKey = new DataColumn[] { empDt.Columns["ID"] };
 
             //增加行数据
             foreach (Employee oneEmp in Employee.GetEmployeeList())
             {
                 //获取一个符合Employee表架构的Row对象
                 //DataRow oneData = empDt.NewRow();
 
                 //oneData["ID"] = oneEmp.ID;
                 //oneData["FullName"] = oneEmp.FullName;
                 //oneData["PhoneNumber"] = oneEmp.PhoneNumber;
                 //oneData["Email"] = oneEmp.Email;
                 //empDt.Rows.Add(oneData);
                 empDt.Rows.Add(new object[] { oneEmp.ID, oneEmp.FullName, oneEmp.PhoneNumber, oneEmp.Email });
             }
             return empDt;
         } 

5.双击DataGridView任意行时，编辑行数据

         /// <summary>
         /// 双击任意单元格发生
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void Employee_DataGrid_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
         {
             if (e.RowIndex == -1) return;
             this.btn_delete.Enabled = true;
 
             Employee oneEmployee = new Employee();
 
             int currentIndex = Employee_DataGrid.CurrentCell.RowIndex;
             oneEmployee.ID = (Int64)(this.Employee_DataGrid.Rows[currentIndex].Cells[0].Value);
             oneEmployee.FullName = this.Employee_DataGrid.Rows[currentIndex].Cells[1].Value.ToString();
             oneEmployee.PhoneNumber = this.Employee_DataGrid.Rows[currentIndex].Cells[2].Value.ToString();
             oneEmployee.Email = this.Employee_DataGrid.Rows[currentIndex].Cells[3].Value.ToString();
 
             //DataRow editRow = (this.Employee_DataGrid.Rows[currentIndex].DataBoundItem as DataRowView).Row;
             DataRow editRow = (this.Employee_DataGrid.CurrentRow.DataBoundItem as DataRowView).Row;
 
             EmployeeDetail detail = new EmployeeDetail(this.EmployeeTable, oneEmployee, editRow, TableAction.Edit);
 
             if (detail.ShowDialog() == DialogResult.OK)
             {
                 //DataRow oneRow = detail.EmployeeEntry;
                 //删除成功
                 MessageBox.Show("修改成功!");
             }
         }

6.添加删除数据行的代码

        /// <summary>
        /// 删除数据行
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btn_delete_Click(object sender, EventArgs e)
        {
            if (Employee_DataGrid.Rows.Count > 0)
            {
                int currentIndex = Employee_DataGrid.CurrentCell.RowIndex;

                DataRow editRow = (this.Employee_DataGrid.CurrentRow.DataBoundItem as DataRowView).Row;
                // DataRow editRow = (this.Employee_DataGrid.Rows[currentIndex].DataBoundItem as DataRowView).Row;
                if (editRow != null)
                {
                    editRow.Delete();
                    this.EmployeeTable.AcceptChanges();
                }
            }
        }

7.添加增加数据行的代码

        /// <summary>
        /// 增加数据行
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btn_Add_Click(object sender, EventArgs e)
        {
            EmployeeDetail detail = new EmployeeDetail(this.EmployeeTable, TableAction.Add);
            if (detail.ShowDialog() == DialogResult.OK)
            {
                DataRow oneRow = detail.EmployeeEntry;
                try
                {
                    this.EmployeeTable.Rows.Add(oneRow);
                    this.EmployeeTable.AcceptChanges();
                }
                catch (Exception ex)
                {
                    MessageBox.Show("错误:" + ex.Message);
                }
            }
        }

最后我们运行示例程序:

增加数据:

编辑数据:

删除数据:

猛击下载：示例源码

作者：晴天猪

出处：http://www.cnblogs.com/IPrograming 

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