Question

gridview怎么实现增删改查学习

Answer 1

using System;
using System.Collections.Generic;
using System.Web.UI.WebControls;

namespace WebApplicationSample
{

/// <summary>
/// 这个实例主要演示了如何使用GridView进行数据的增、删、改、查。
/// 更多有关于该控件的知识，可以参考 http://msdn.microsoft.com/zh-cn/library/vstudio/system.web.ui.webcontrols.gridview.aspx （请仔细阅读）
/// </summary>
public partial class Default : System.Web.UI.Page
{
/// <summary>
/// 这是我们定义的一个业务实体类，用来保存界面上的列表数据，为了保存，必须支持序列化
/// </summary>
[Serializable]
public class Employee
{
public string FirstName { get; set; }
public string LastName { get; set; }
}

private List<Employee> data = new List<Employee>();//这是用来保存那个列表数据的字段
/// <summary>
/// 重写这个方法来保存视图状态。因为每次页面刷新的时候，默认情况下，data都会被清空，如果希望在多次回发的过程中保存数据，则重写该方法
/// </summary>
/// <returns></returns>
protected override object SaveViewState()
{
var obj = new object[] { base.SaveViewState(), data };
return obj;
}
/// <summary>
/// 重写该方法，是与上面这个方法配套，在回发回来之后加载并还原
/// </summary>
/// <param name="savedState"></param>
protected override void LoadViewState(object savedState)
{
var obj = savedState as object[];

base.LoadViewState(obj[0]);
data = obj[1] as List<Employee>;
}
/// <summary>
/// 页面初始化的时候执行该代码
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{//这里只是一个示例，默认给页面添加一个初始的员工，实际在做的时候，可以不加
data = new List<Employee>(){
new Employee(){FirstName ="ares",LastName ="chen"}
};

gvData.DataSource = data;
gvData.DataBind();
}
}

/// <summary>
/// 添加新的员工时执行该代码
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btAddNew_Click(object sender, EventArgs e)
{
data.Add(new Employee());//创建一个空的对象
gvData.DataSource = data;//设置数据源
gvData.EditIndex = data.Count - 1;//设置当前这个对象为编辑状态
gvData.DataBind();//绑定数据

}

/// <summary>
/// 当用户决定要删除某一行数据时执行该代码
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void gvData_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
//删除某一行
data.RemoveAt(e.RowIndex);
gvData.DataSource = data;
gvData.EditIndex = -1;
gvData.DataBind();
}
/// <summary>
/// 当用户要保存修改时执行该代码
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void gvData_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
var index = e.RowIndex;//获取当前编辑行当索引号
var row = gvData.Rows[index];//获取当前用户编辑的这一行

var firstName = (row.Cells[1].Controls[0] as TextBox).Text;//获取用户输入的数据
var lastName = (row.Cells[2].Controls[0] as TextBox).Text;//获取用户输入的数据

var emp = data[index];//找到这个对象
emp.FirstName = firstName;
emp.LastName = lastName;

gvData.DataSource = data;
gvData.EditIndex = -1;//退出编辑状态
gvData.DataBind();
}
/// <summary>
/// 当用户要取消编辑的时候
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void gvData_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
gvData.DataSource = data;
gvData.EditIndex = -1;
gvData.DataBind();
}
/// <summary>
/// 当用户要进行编辑的时候
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void gvData_RowEditing(object sender, GridViewEditEventArgs e)
{
gvData.DataSource = data;
gvData.EditIndex = e.NewEditIndex;
gvData.DataBind();
}
}
}