将项目添加到Web用户控件 [英] Add items to a Web Usercontrol

问题描述

我正在创建一个网站，希望在其中提供一些简洁的上下文菜单控件.我已经找到了一些方便的代码来创建菜单(但是，如果您拥有"em"，则发布"em")，但是我正在寻找为该站点创建标准UC的代码.我希望能够以与HTML select甚至asp:dropdown相同的方式向控件添加项目(更可能是后者，因为HTML将以相同的方式从代码中生成). />
这有可能吗?

Hi,

I am creating a website where I would like some neat context menu controls. I have already found some handy code to create the menu (but post ''em if you''ve got ''em) but I''m looking to create a standard UC for the site. I was hoping to be able to add items to the control in the same way that an HTML select does or even the asp:dropdown does (more likely the latter as the HTML will be produced from the code in the same way).

Is this even possible?

<uc:ContextMenu id="CustomControl">
   <uc:MenuLink Value="blah" Text="blah" Url="\blah" />
   <uc:MenuButton  Value="blah" Text="blah"  önClick="Blah_OnClick" />
</uc:ContextMenu>

以及如何完成?
也许与winform用户控件中的设计时属性相同?

PS:我还没有真正开始查看控件属性，因此请发布有关将这些属性添加到控件的任何有用信息

在此先感谢^ _ ^

And how is it done?
Maybe it''s the same as design time attributes in winform user controls?

PS: I haven''t really started looking at control attributes yet so please post any useful info on adding these to the control

Thanks in advance ^_^

推荐答案

所以我了解到，您需要用户控件具有可通过aspx标记设置的属性.

如果您在用户控件中定义了公共属性，则可以像使用页面中的属性一样使用它''asp.net标记.

告诉我，如果我的理解不正确.

So What i understood is that you need your user control to have the attributes that you can set from aspx markup.

If you define public properties in your user control then use can use it like attributes from you pages'' asp.net markup.

Tell me If my understanding is not correct.

您需要在封闭的类中添加以下内容:

You need to add the following to your enclosing class:

[ParseChildren(false)]
[PersistChildren(true)]
public partial class ContextMenu : UserControl
{...}

这样，您就可以在UserControl的开始和结束标记之间添加项目.我还在ContextMenuitem类中包含了这些标签，以便可以添加无限嵌套的子菜单

您可能要使用的另一个重载是

That will allow you to add items between the opening and closing tags of your UserControl. I have also included those tags on my ContextMenuitem class so that I can add infinite nested submenus

Another overload you may want to use is

protected override void AddedControl(Control control, int index)
{
  try
  {
    ContextMenuItem cmitem = ((ContextMenuItem)control);

    if (_subItems == null)
      _subItems = new List<contextmenuitem>();

    List<contextmenuitem> newlist = new List<contextmenuitem>();

    newlist.AddRange(_subItems.AsQueryable().Take(index).ToList());
    newlist.Add(cmitem);
    newlist.AddRange(_subItems.AsQueryable().TakeWhile((item, i) => i >= index));

    _subItems = newlist;
  }
  catch (InvalidCastException ice)
  {
    //This is an expected error more several controls which should not be parsed here anyway
  }
}
</contextmenuitem></contextmenuitem></contextmenuitem>

您可以对几种不同的类类型执行检查，也可以使用继承，只要每个控件具有相同的属性即可.

我个人使用了一个项目类，使RenderControl重载，因此它什么也不做，并在一个新的RenderHtml中编写了标记，我从ContectMenu类的``Render控件''调用了该标记.这样，您无需担心HtmlControl RenderControl被调用.自己写吧:

You could perform a check for several different class types or use inheritance, so long as each control has the same properties.

I personally used one item class, overloaded the RenderControl so that it did nothing and wrote the markup in a new RenderHtml that I called from the ContectMenu class'' Render control. That way you don''t need to worry about the HtmlControl RenderControl being called. Just write it yourself:

public override void RenderControl(HtmlTextWriter writer){}
public void Renderhtml(HtmlTextWriter writer, string previousId, int iteration = 0)
{
  writer.WriteFullBeginTag("li");

  string currentId = previousId + "_" + iteration.ToString();

  if (this.ViewState["ControlStyle"] != null)
  {

    Control_Style style = (Control_Style)Enum.Parse(typeof(Control_Style), this.ViewState["ControlStyle"].ToString());

    string closeTag = string.Empty;

    switch (style)
    {
      case Control_Style.Button:
        writer.WriteBeginTag("button");
        closeTag = "</button>";
        break;
      case Control_Style.Hyperlink:
        writer.WriteBeginTag("a");
        closeTag = "";
        break;
      case Control_Style.SubMenu:
        writer.WriteBeginTag("span");
        closeTag = "";
        break;
    }

    foreach (object key in this.ViewState.Keys)
    {
      if (this.ViewState[key.ToString()] != null && this.ViewState[key.ToString()].ToString().Length > 0)
      writer.WriteAttribute(key.ToString(), this.ViewState[key.ToString()].ToString());
    }
    writer.Write(">");
    writer.WriteLine(this.Text);
    writer.WriteLine(closeTag);

    if (_subItems != null && _subItems.Count > 0)
    {
      writer.WriteBeginTag("div");
      writer.WriteAttribute("id", currentId);
      writer.Write(">");

      writer.WriteFullBeginTag("ul");
      foreach (ContextMenuItem cmi in _subItems)
      {
        cmi.Renderhtml(writer, currentId);
      }
      writer.WriteEndTag("ul");
      writer.WriteEndTag("div");
    }
  }
  else
    throw new HttpUnhandledException("Menu Items must be either a HtmlControls or a Sub Menu!");

  writer.WriteEndTag("li");

}

这实在是太过分了，但是我还确保了我的子菜单div具有独特的ID，以便可以使每个javascript都能正常工作.我仍然还没有工作，但是如果有人在完成后需要它，我会把它贴出来:D

This is prolly overkill but I have also made sure that my submenu divs have distinctive IDs so that I can make the javascript work over each one. I still haven''t got that bit working yet but I''ll post it if anyone needs it when I''m done :D

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