3) 后端代码

最后，我们需要写一些后端代码来处理新闻分类和分页。在Page_Load事件中，我们将调用BindData方法来绑定GridView和AspNetPager控件。在BindData方法中，我们将从数据库中获取新闻数据并根据当前选择的分类来筛选数据。然后，我们将数据绑定到GridView控件并设置AspNetPager控件的总记录数和当前页码。

下面是后端代码示例：

public partial class _Default : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

BindCategory();

BindData();

}

}

protected void BindCategory()

{

List categoryList = new List();

categoryList.Add(new Category { ID = 0, Name = "All" });

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["connStr"].ConnectionString);

string sql = "SELECT * FROM Category";

SqlCommand cmd = new SqlCommand(sql, conn);

conn.Open();

SqlDataReader dr = cmd.ExecuteReader();

while (dr.Read())

{

Category category = new Category();

category.ID = Convert.ToInt32(dr["ID"]);

category.Name = dr["Name"].ToString();

categoryList.Add(category);

}

conn.Close();

ddlCategory.DataSource = categoryList;

ddlCategory.DataTextField = "Name";

ddlCategory.DataValueField = "ID";

ddlCategory.DataBind();

}

protected void BindData()

{

int pageIndex = AspNetPager1.CurrentPageIndex - 1;

int pageSize = AspNetPager1.PageSize;

string categoryID = ddlCategory.SelectedValue;

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["connStr"].ConnectionString);

string sql = "SELECT a.ID, a.Title, a.Content, a.CreateTime, b.Name AS CName FROM News a LEFT JOIN Category b ON a.CategoryId=b.ID";

if (categoryID != "0")

{

sql += " WHERE a.CategoryId=" + categoryID;

}

sql += " ORDER BY CreateTime DESC OFFSET " + pageIndex * pageSize + " ROWS FETCH NEXT " + pageSize + " ROWS ONLY";

SqlCommand cmd = new SqlCommand(sql, conn);

conn.Open();

SqlDataReader dr = cmd.ExecuteReader();

List newsList = new List();

while (dr.Read())

{

News news = new News();

news.ID = Convert.ToInt32(dr["ID"]);

news.Title = dr["Title"].ToString();

news.Content = dr["Content"].ToString();

news.CreateTime = Convert.ToDateTime(dr["CreateTime"]);

news.CategoryName = dr["CName"].ToString();

newsList.Add(news);

}

conn.Close();

gvNews.DataSource = newsList;

gvNews.DataBind();

sql = "SELECT COUNT(*) FROM News";

if (categoryID != "0")

{

sql += " WHERE CategoryId=" + categoryID;

}

cmd = new SqlCommand(sql, conn);

conn.Open();

AspNetPager1.RecordCount = Convert.ToInt32(cmd.ExecuteScalar());

AspNetPager1.DataBind();

conn.Close();

}

protected void ddlCategory_SelectedIndexChanged(object sender, EventArgs e)

{

BindData();

}

protected void AspNetPager1_PageChanged(object sender, EventArgs e)

{

BindData();

}

}

四、总结

AspNetPager是一个非常方便的ASP.NET分页控件，可以轻松地实现在ASP.NET网站中显示数据列表和分页功能。它提供了大量的属性和方法，可以满足大多数分页需求。在使用AspNetPager时，只需按照固定的步骤进行设置即可。本文提供了一些简单的示例代码，希望读者可以掌握AspNetPager的使用。 如果你喜欢我们三七知识分享网站的文章， 欢迎您分享或收藏知识分享网站文章 欢迎您到我们的网站逛逛喔！https://www.37seo.cn/