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2003-08-25 11:58:04 160 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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Notion卡顿救星：3分钟搞定DNS优化，手机电脑全平台加速指南本文针对Notion访问慢和卡顿问题，提供了全平台DNS优化与Hosts文件修改的详细指南。通过更换优质DNS服务器或建立静态IP映射，可有效解决因网络延迟和域名解析导致的加载缓慢，实现手机与电脑端的快速加速，提升Notion使用流畅度。阅读详情

昨天那个自定义的派生于DATALIST的可分页的SUNDATALIST的问题
你建议我看的例子，我已经看了，谢谢！，
今天重载了RENDER，
如下：
override protected void Render(HtmlTextWriter writer)
{

RenderContents(writer);
btnPrev.RenderControl(writer);

btnMore.RenderControl(writer);

}
我在重载的 CreateControlHierarchy 方法里
添加了两个按钮控件
如下：
override protected void CreateControlHierarchy(bool useDataSource)
{
base.CreateControlHierarchy(useDataSource);
btnPrev = new ImageButton();

btnPrev.Click += new ImageClickEventHandler(PreviousClicked);
Controls.Add(btnPrev);

btnMore = new ImageButton();

btnMore.Click += new ImageClickEventHandler(MoreClicked);
Controls.Add(btnMore);
}

问题解决！
但是我想不通，为什么在CreateControlHierarchy 方法里添加的两个按钮控件
在DATALIST.RENDER()里会出现类型转换无效这个问题呢？
我重载的RENDER里我自己为什么还要手工RENDER按钮呢？
请指教！

...全文

Cartographer纯定位实战：从仿真到真机部署的避坑指南本文详细介绍了将Cartographer算法应用于机器人纯定位模式的完整实战流程。通过对比传统AMCL方案的不足，阐述了Cartographer基于子图匹配实现高精度、高鲁棒性定位的优势。内容涵盖从仿真环境测试到真机部署的核心步骤，包括关键配置文件修改、源码调整以及参数调优，旨在帮助开发者避开常见陷阱，成功实现稳定可靠的机器人定位系统。阅读详情

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wjcking 2003-08-25

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saucer 2003-08-25

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I forgot the details, but if you have used
Controls.Add(btnPrev);

then you shouldn't need to do
btnPrev.RenderControl(writer);

that is, you don't need to override Render at all

saucer 2003-08-25

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try the following:

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;

namespace CSDNControls
{
/// <summary>
/// Summary description for MyDataList.
/// </summary>
[ToolboxData("<{0}:MyDataList runat=server></{0}:MyDataList>")]
public class MyDataList : System.Web.UI.WebControls.DataList
{
Button btnPrev, btnNext;
protected override void CreateControlHierarchy(bool useDataSource)
{
base.CreateControlHierarchy(useDataSource);

DataListItem dli = new DataListItem(0, ListItemType.Item);

btnPrev = new Button();
btnPrev.Text = "Previous";
btnPrev.Click += new EventHandler(Button_Clicked);
dli.Controls.Add(btnPrev);

btnNext = new Button();
btnNext.Text = "Next";
btnNext.Click += new EventHandler(Button_Clicked);
dli.Controls.Add(btnNext);

Controls.Add(dli);
}

private void Button_Clicked(Object sender, EventArgs e)
{
Button btn = (Button)sender;
Page.Response.Write(btn.Text + " is clicked");
}

protected override void Render (HtmlTextWriter writer)
{
base.Render(writer);
//you still have to call the following, since the base.Render will not render them
btnPrev.RenderControl(writer);
btnNext.RenderControl(writer);
}
}
}

saucer 2003-08-25

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I was wrong, inside DataList.Render method, it does some preparation (like applying styles) on the controls, i.e., Items, it probably tries to cast your buttons to DataListItem, but failed

it was ok in the above code of yours because you called
RenderContents(writer);

and bypassed the other methods

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