C＃.net使事件从Page冒泡到用户控件（子控件）
[英]C# .net bubble down an event from Page to usercontrol (child)
问题描述
Can a usercontrol (child, doesStuff.ascx) page react to an event from Page (parent, page.aspx)? 
用户控件（子级，stuff.ascx）页面可以对页面（父级，page.aspx）中的事件做出反应吗？ I have a button on the parent page. 我在父页面上有一个按钮。 Onclick i'd like to fire an event on the child. Onclick我想向孩子触发一个事件。
doesStuff.ascx: doesStuff.ascx：
//something like this //这样的东西
((doesStuff)this.Page).someButtonControl.click;
// or // 要么
something.Click += new EventHandler(someReference???);
2 个解决方案
解决方案1
1 2017-02-05 21:19:31
If i truly understand you, You can use delegate to this purpose. 如果我真正了解您，则可以为此目的使用委托。 In user control uc1: 在用户控件uc1中：
public Action action;
protected void btnSubmit_Click(object sender, EventArgs e)
{
action();
}
And in the page: 并在页面中：
protected void Page_Load(object sender, EventArgs e)
{
uc1.action = someAction;
}
public void someAction()
{
//Do Some thing
}
解决方案2
1 已采纳 2017-02-06 02:16:56
Child to Parent Bubble Up 孩子对父母的泡沫
If you want to pass argument from child control to parent, you can use CommandEventHandler . 如果要将参数从子控件传递给父控件，则可以使用CommandEventHandler 。
Parent ASPX 父ASPX
<%@ Register Src="~/DoesStuff.ascx" TagPrefix="uc1" TagName="DoesStuff" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<body>
<form id="form1" runat="server">
<uc1:DoesStuff runat="server" ID="DoesStuff"
OnChildButtonClicked="DoesStuff_ChildButtonClicked" />
</form>
</body>
</html>
Parent Code Behind 背后的父代码
public partial class Parent : System.Web.UI.Page
{
protected void DoesStuff_ChildButtonClicked(object sender, EventArgs e) { }
}
Child ASCX 儿童ASCX
<asp:Button ID="BubbleUpButton" runat="server"
Text="Bubble Up to Parent"
OnClick="BubbleUpButton_OnClick" />
Child Code Behind 后面的子代码
public partial class DoesStuff : System.Web.UI.UserControl
{
public event EventHandler ChildButtonClicked = delegate { };
protected void BubbleUpButton_OnClick(object sender, EventArgs e)
{
// bubble up the event to parent.
ChildButtonClicked(this, new EventArgs());
}
}
Parent to Child 父母对孩子
It is not a good practice in ASP.Net Web Form to calling one event to another event without underlying control. 在ASP.Net Web窗体中 ，没有基础控件就将一个事件调用到另一个事件不是一个好习惯。
Instead, you want to create a public method, and call it from Parent. 相反，您想创建一个公共方法，并从Parent调用它。 For example, 例如，
// Parent
public partial class Parent : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
var doesStuff = DoesStuff1 as DoesStuff;
if (doesStuff != null) DoesStuff1.DisplayMessage("Hello from Parent!");
}
}
// Child
public partial class DoesStuff : System.Web.UI.UserControl
{
public void DisplayMessage(string message)
{
ChildLabel.Text = message;
}
}
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.