在后面的每个 asp:DropDownList 控件代码周围添加 DIV [英] add DIV around every asp:DropDownList control code behind

问题描述

我尝试简单地在全局级别(如果可能)围绕 <asp:DropDownList> 类型的每个控件添加一个 div 包装器.在这一点上，我已经用一个 asp 皮肤解决了这个问题，向所有 <asp:DropDownList> 添加了default-select"类，然后 jquery 只为它们每个添加一个 div.

$j(".default-select").wrap("<div class='myClass'></div>");

现在，我的问题.是否可以从代码隐藏中添加此 div 包装器，而不是依赖于 javascript.

控制适配器:我知道这应该可以通过编写一个控制适配器来覆盖 <asp:DropDownList> 渲染方法(如下所述:使用 s for asp.net (webforms) 的下拉列表控件?).但是，我只想添加一个包装 div，而不是重写 <asp:DropDownList> 控件的整个呈现(如果我覆盖该方法，我必须这样做?).有什么建议?也许有一种方法可以在现有的适配器中添加一些东西??

自定义用户控件:另一种解决方案是使用包装构建自定义 <mycustom:DropDownList>，但是，这将迫使我替换 贯穿整个项目(大型项目).我宁愿只是更改原始控件的一些方式，以便我的样式适用于所有地方.

总结:是否有一种简单的方法可以让所有 呈现为:

<select><option...></select>

而不仅仅是:

我的第一次尝试(在页面加载时):我尝试在 Page_load 方法中添加此代码，但我找不到任何方法来渲染该 div?

 var j = 0;foreach(Page.Controls.OfType()中的DropDownList控件){HtmlGenericControl div = new HtmlGenericControl();div.ID = "div" +j;div.TagName = "div";div.Attributes["class"] = "myClass";div.Controls.Add(控件);//或 control.Controls.Add(div);但这不会包装它.j++;}

解决方案

您的解决方案几乎有效.服务器控件只能存在于服务器窗体的范围内，您将需要在页面上执行递归搜索或直接在窗体控件集合中查找.一旦您拥有 DropDownList 并将其包裹在 div 容器中，就需要将其添加到控件集合中.

此外，我认为最好在 OnPreInit 中执行此操作.

protected override void OnPreInit(EventArgs e){base.OnPreInit(e);无功j = 0;foreach(form1.Controls.OfType().ToList()中的DropDownList控件){var div = new HtmlGenericControl();div.ID = "div" + j;div.TagName = "div";div.Attributes["class"] = "myClass";div.Controls.Add(控件);//或 control.Controls.Add(div);但这不会包装它.j++;form1.Controls.Add(div);}

}

我希望这会有所帮助.让我知道你的进展如何.

I try to simply add a div wrapper around every control of type <asp:DropDownList> at a global level (if possible). At this point I have solved it with a asp skin adding "default-select" class to all <asp:DropDownList> and then jquery just adding a div for each of them.

$j(".default-select").wrap("<div class='myClass'></div>");

Now, my question. Is it possible to add this div wrapper from the code-behind instead of relying on a javascript.

Control Adapter: I know this should be possible by writing a control adapter that override <asp:DropDownList> render method (as described here: Dropdownlist control with <optgroup>s for asp.net (webforms)?). However, I just want to add a wrapping div, not rewrite the entire rendering of the <asp:DropDownList> control (which I have to do if i override the method?). Any suggestions? Maybe there is a way to just add something to the existing adapter??

Custom User Control: Another solution would be to build a custom <mycustom:DropDownList> with the wrapping, but, this would force me to replace every instance of <asp:DropDownList> trough the whole project (large project). I rather just change the original control some how so that my styling applies everywhere.

So summary: Is there an easy way to just make all <asp:DropDownList> render as:

<div class="myClass">
      <select><option...></select>
</div>

instead of just:

<select><option...></select>

My first attempt (on Page load): I tried to add this code in the Page_load method but I don't find any way to render that div out?

    var j = 0;
    foreach (DropDownList control in Page.Controls.OfType<DropDownList>())
    {

       HtmlGenericControl div = new HtmlGenericControl();
        div.ID = "div" +j;
        div.TagName = "div";
        div.Attributes["class"] = "myClass";
        div.Controls.Add(control); // or control.Controls.Add(div); but this wouldn't wrap it.
        j++;
    }

解决方案

Your solution just about works. Server control can only exist within the scope of a server form, you will need to perform a recursive search on the page or look directly in the form controls collection. Once you have the DropDownList and wrapped it around a div container it will need to be added to the controls collection.

Also, I think it better to perform this in OnPreInit.

protected override void OnPreInit(EventArgs e)
{
base.OnPreInit(e);

var j = 0;
foreach (DropDownList control in form1.Controls.OfType<DropDownList>().ToList())
{
    var div = new HtmlGenericControl();
    div.ID = "div" + j;
    div.TagName = "div";
    div.Attributes["class"] = "myClass";
    div.Controls.Add(control); // or control.Controls.Add(div); but this wouldn't wrap it.
    j++;

    form1.Controls.Add(div);
}

}

I hope this is helpful. Let me know how you get on.

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