从孩子共享价值于母公司控制 [英] Sharing value from child to parent control

问题描述

我是比较新的这一点，但这里是我的问题。

I am relatively new to this, but here is my problem.

在asp.net，我有一个父和子控制。在子控件我有一个下拉列表。根据下拉列表中的选择的价值，我想切换面板的可见性在父母的控制。举例来说，如果我在子控件下拉列表中选择显示，我需要通过真正的母公司控制，使面板可见，反之亦然。我应该怎样做。我已阅读，可以通过事件处理完成，并且已经看到某些情况下，但我并不清楚这一点。请帮助！

In asp.net, I have a parent and a child control. Within the child control I have a dropdown list. Based on dropdown list's selected value I would like to toggle Visibility of Panel in parent control. For instance if I select Show in child control dropdown list, I need to pass true to parent control to make Panel visible and vice versa. How should I do that. I have read that can be done via the event handling and have seen certain scenarios but I am not clear on that. Please help!

感谢。

推荐答案

抬起你的父控件侦听事件。

Raise an event that your parent control listens for.

在背后为你的父母控制code，创建子控件的类型的对象。是这样的：

In the code behind for your parent control, create an object of the type of your child control. Something like:

private MyWebControl childControl;

然后在子控件，定义事件

Then in the child control, define an event

public event System.EventHandler SelectionChanged;

在你的DropDownList的OnIndexChanged事件后，你做你的处理，提高您的活动：

In the OnIndexChanged event of your DropDownList, after you do your processing, raise your event:

if(this.SelectionChanged!= null)
{
     this.SelectionChanged(this, new EventArgs()); 
     // You can send the index of the DDL in the event args
}

在您的父母控制，连接了该事件。 Page_Init好

In your parent control, wire up the event. Page_Init is good

this.childControl.SelectionChanged+=new EventHandler(childControl_SelectionChanged);

仍然在父控件，定义方法

Still in the parent control, define your method

private void childControl_SelectionChanged(object sender, EventArgs e)
{
      /// Do your processing here.
      /// Grab the DDL's index from the EventArgs and do your processing

}

应该是所有你需要得到它的工作！

Should be all you need to get it working!

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