查找一个WebForm控制 [英] Find a control in a webform

问题描述

我有一个Web内容的形式和需要访问该内容面板内的控制。我所知道的访问控制两种方式：

I have a Web content form and need to access a control inside the content panel. I know of two ways to access the control:

1. TXT文本框=（文本框）Page.Controls [0] .Controls [3] .Controls [48] .Controls [6]


2. 将编写一个递归函数，通过所有的控制搜索。

有没有其他更简单的方法，因为 Page.FindControl 不会在这种情况下工作。
我问的原因是感觉对我来说，Page对象或内容面板对象应该有发现孩子控制的方法，却找不到这样的事情。

Is there any other easier way, since Page.FindControl doesn’t work in this instance. The reason I am asking is it feels to me like the Page object or the Content Panel object should have a method to find a child control, but can’t find anything like it.

推荐答案

的问题是的FindControl（）不经过一定的控制的孩子，如模板化控件。如果控制你所追求的生活在一个模板，它不会被发现。

The issue is that FindControl() does not traverse certain control children such as a templated control. If the control you are after lives in a template, it won't be found.

所以我们将以下扩展方法来处理这​​个问题。如果你不使用3.5或想避免的扩展方法，你可以做一个通用库出这些。

So we added the following extension methods to deal with this. If you are not using 3.5 or want to avoid the extension methods, you could make a general purpose library out of these.

您现在可以得到控制你是后编码：

You can now get the control you are after by coding:

var button = Page.GetControl("MyButton") as Button;

扩展方法为你做递归工作。希望这有助于！

The extension methods do the recursive work for you. Hope this helps!

public static IEnumerable<Control> Flatten(this ControlCollection controls)
{
    List<Control> list = new List<Control>();
    controls.Traverse(c => list.Add(c));
    return list;
}

public static IEnumerable<Control> Flatten(this ControlCollection controls,     
    Func<Control, bool> predicate)
{
    List<Control> list = new List<Control>();
    controls.Traverse(c => { if (predicate(c)) list.Add(c); });
    return list;
}

public static void Traverse(this ControlCollection controls, Action<Control> action)
{
    foreach (Control control in controls)
    {
        action(control);
        if (control.HasControls())
        {
            control.Controls.Traverse(action);
        }
    }
}

public static Control GetControl(this Control control, string id)
{
    return control.Controls.Flatten(c => c.ID == id).SingleOrDefault();
}

public static IEnumerable<Control> GetControls(this Control control)
{
    return control.Controls.Flatten();
}

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