我是ASP.Net世界的新手，对如何处理下面的场景感到困惑。
在我的应用程序中，我必须在加载页面时从数据库中获取数据并在GridView中显示它。该表目前有大约1000条记录，大约有7列。但数据将继续增长。
这是我如何将数据绑定到网格的代码。
protected void Page_Load(object sender, EventArgs e)
{
var data = new AppsAuthData().GetAllUsers();
gridUsersInfo.DataSource = data;
gridUsersInfo.DataBind();
}
我开始知道在上面的每个帖子上代码都会被执行（这显然不是很好）。所以我在函数的开头添加了以下内容
if (IsPostBack)
return;
var data = new AppsAuthData().GetAllUsers();
gridUsersInfo.DataSource = data;
gridUsersInfo.DataBind();
页面标记
<%@ Page Language="C#" AutoEventWireup="true" MasterPageFile="~/Site.Master" CodeBehind="RemoveUsers.aspx.cs" Inherits="AppsAuth.Authencations.RemoveUsers" %>
这又有一个问题，在Postbacks之后，GridView没有任何东西可以显示。接下来我将结果保存到ViewState，然后在每个帖子上我检索/更新了ViewState。
但由于在某些情况下数据可能很大，那么处理此类问题的最佳选择是什么？
GridView片段
<asp:GridView ID="gridUsersInfo" runat="server" Width="100%" ForeColor="#333333" AllowPaging="True"
AllowSorting="True" AutoGenerateColumns="false" OnSorting="UserInfo_Sorting" OnRowEditing="gridUsersInfo_RowEditing"
OnPageIndexChanging="gridUsersInfo_PageIndexChanging" AutoGenerateEditButton="True">
> <Columns>
<asp:BoundField DataField="USER_ID" ReadOnly="True" HeaderText="ID" SortExpression="USER_ID" />
<asp:BoundField DataField="USER_NAME" ReadOnly="False" HeaderText="User Name" SortExpression="USER_NAME" />
</Columns>
</asp:GridView>
protected void gridUsersInfo_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
gridUsersInfo.PageIndex = e.NewPageIndex;
gridUsersInfo.DataBind();
}
而不是把所有内容放在页面加载上。您可以放置一个按钮并编写代码以在该按钮的单击事件中填充GridView。
使用启用了分页的asp.net控件Gridview将为您完成此操作。
请检查以下示例：
HTML
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" AllowPaging="true"
OnPageIndexChanging="OnPageIndexChanging" PageSize="10">
<Columns>
<asp:BoundField ItemStyle-Width="150px" DataField="CustomerID" HeaderText="Customer ID" />
<asp:BoundField ItemStyle-Width="150px" DataField="ContactName" HeaderText="Contact Name" />
<asp:BoundField ItemStyle-Width="150px" DataField="City" HeaderText="City" />
<asp:BoundField ItemStyle-Width="150px" DataField="Country" HeaderText="Country" />
</Columns>
</asp:GridView>
代码隐藏
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
this.BindGrid();
}
}
private void BindGrid()
{
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("SELECT CustomerId, ContactName, City, Country FROM Customers"))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataTable dt = new DataTable())
{
sda.Fill(dt);
GridView1.DataSource = dt;
GridView1.DataBind();
}
}
}
}
}
实施分页
在GridView中更改页面时，将调用事件处理程序。单击的PageIndex的值存在于GridViewPageEventArgs对象的NewPageIndex属性中，并且它被设置为GridView的PageIndex属性，并且通过调用BindGrid函数再次填充GridView。
protected void OnPaging(object sender, GridViewPageEventArgs e)
{
GridView1.PageIndex = e.NewPageIndex;
GridView1.DataBind();
}
资料来源：http://www.aspsnippets.com/Articles/Paging-in-ASPNet-GridView-Example.aspx
你需要做的就是在page_load中使用！isPostback时绑定绑定gridview
if(!IsPostBack)
{ var data = new AppsAuthData().GetAllUsers();
ViewState["UserData"] = data;
gridUsersInfo.DataSource = data;
gridUsersInfo.DataBind();
}
听到就是一个例子：Asp.Net Bind Grid View
在.aspx文件中
<form runat="server" onload="Page_Load">
<asp:GridView runat="server" ID="gridEvent" AutoGenerateColumns="False" BackColor="White"
BorderStyle="None" BorderWidth="0px" class="table mb-0"
>
<RowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="EventId" HeaderText="#" />
<asp:BoundField DataField="Title" HeaderText="Event Title" />
<asp:BoundField DataField="EventDate" HeaderText="Event Date" />
<asp:BoundField DataField="Location" HeaderText="Venue" />
<asp:BoundField DataField="RegisteredUsers" HeaderText="Registred User(s)" />
<asp:CommandField ShowEditButton="True" />
<asp:CommandField ShowDeleteButton="True" />
</Columns>
<FooterStyle BackColor="#99CCCC" ForeColor="#003399" />
<PagerStyle BackColor="#99CCCC" ForeColor="#003399" HorizontalAlign="Left" />
<SelectedRowStyle BackColor="#009999" Font-Bold="True" ForeColor="#CCFF99" />
<HeaderStyle BackColor="#FBFBFB" Font-Bold="True" ForeColor="#5A6169" />
</asp:GridView>
</form>
在.aspx.designer.cs中
public partial class Default
{
/// <summary>
/// txtLocation control.
/// </summary>
/// <remarks>
/// Auto-generated field.
/// To modify move field declaration from designer file to code-behind file.
/// </remarks>
protected global::System.Web.UI.WebControls.GridView gridEvent;
}
在.aspx.cs文件中
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
// Enable the GridView paging option and
// specify the page size.
gridEvent.AllowPaging = true;
gridEvent.PageSize = 15;
// Initialize the sorting expression.
ViewState["SortExpression"] = "EventId ASC";
// Enable the GridView sorting option.
gridEvent.AllowSorting = true;
BindGrid();
}
}
private void BindGrid()
{
// Get the connection string from Web.config.
// When we use Using statement,
// we don't need to explicitly dispose the object in the code,
// the using statement takes care of it.
using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["sqlConn"].ToString()))
{
// Create a DataSet object.
DataSet dsPerson = new DataSet();
// Create a SELECT query.
string strSelectCmd = "SELECT * FROM EventsList";
// Create a SqlDataAdapter object
// SqlDataAdapter represents a set of data commands and a
// database connection that are used to fill the DataSet and
// update a SQL Server database.
SqlDataAdapter da = new SqlDataAdapter(strSelectCmd, conn);
// Open the connection
conn.Open();
// Fill the DataTable named "Person" in DataSet with the rows
// returned by the query.new n
da.Fill(dsPerson, "EventsList");
// Get the DataView from Person DataTable.
DataView dvPerson = dsPerson.Tables["EventsList"].DefaultView;
// Set the sort column and sort order.
dvPerson.Sort = ViewState["SortExpression"].ToString();
// Bind the GridView control.
gridEvent.DataSource = dvPerson;
gridEvent.DataBind();
}
}
//Implementing Pagination
protected void OnPaging(object sender, GridViewPageEventArgs e)
{
gridEvent.PageIndex = e.NewPageIndex;
gridEvent.DataBind();
}