asp.net 打印 分页 示例

ASP.NET 中打印分页功能通常用于展示大量数据列表，并通过页码让用户逐页浏览。下面是一个基本的例子，展示了如何使用`GridView`控件进行分页打印：

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
    DataSourceID="SqlDataSource1" AllowPaging="True" PageSize="10">
    <Columns>
        <!-- 添加列 -->
    </Columns>
</asp:GridView>

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:YourConnectionString %>"
    SelectCommand="SELECT * FROM YourTable" />

<asp:Button ID="btnPrint" runat="server" Text="打印当前页" OnClick="btnPrint_Click" />

protected void btnPrint_Click(object sender, EventArgs e)
{
    int currentPage = GridView1.PageIndex + 1; // 获取当前页码

    // 创建一个新的HttpResponse对象，模拟打印机输出
    HttpResponse response = HttpContext.Current.Response;
    response.Clear();
    response.ContentType = "application/pdf";
    response.AddHeader("Content-Disposition", "attachment; filename=page_" + currentPage + ".pdf");
    
    // 设置页面范围，例如只打印当前页
    GridView1.PageIndex = currentPage - 1;
    string sql = "SELECT * FROM YourTable OFFSET " + (currentPage - 1) * GridView1.PageSize + " ROWS FETCH NEXT " + GridView1.PageSize + " ROWS ONLY"; // SQL查询以获取指定页的数据
    GridView1.DataSource = SqlDataSource1.SelectCommand = sql;
    GridView1.DataBind();

    // 将GridView的内容发送到响应流
    StringWriter sw = new StringWriter();
    HtmlTextWriter htw = new HtmlTextWriter(sw);
    GridView1.RenderControl(htw);
    response.Write(sw.ToString());

    // 清理并结束响应
    response.Flush();
    response.Close();
}

在这个示例中，用户点击“打印当前页”按钮时，会生成一个PDF文件，包含当前显示的那一页数据。