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Eventhandling in ascx user preferences

Which is best suited for exchanging events from usercontrol to the parent control / page, I want to do something similar to this:

MyPage.aspx:
<asp:Content ID="Content1" ContentPlaceHolderID="MainContentPlaceholder" runat="server">
  <uc1:MyUserControl ID="MyUserControl1" runat="server" 
     OnSomeEvent="MyUserControl_OnSomeEvent" />

MyUserControl.ascx.cs:
public partial class MyUserControl: UserControl
{
    public event EventHandler SomeEvent;
....
   private void OnSomething()
    {
        if (SomeEvent!= null)
            SomeEvent(this, EventArgs.Empty);
    }

Question is best practice?

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3 answers

You want to create an event in the control that the parent element is subscribing to. See OdeToCode for an example.

Here is an article for longevity:

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.

<%@ Control Language="c#" AutoEventWireup="false" 
    Codebehind="WebUserControl1.ascx.cs" 
    Inherits="aspnet.eventbubble.WebUserControl1" 
    TargetSchema="http://schemas.microsoft.com/intellisense/ie5"
%>
<asp:Panel id="Panel1" runat="server" Width="128px" Height="96px">
    WebUserControl1 
    <asp:Button id="Button1" Text="Button" runat="server"/>
</asp:Panel>

.

public class WebUserControl1 : System.Web.UI.UserControl
{
   protected System.Web.UI.WebControls.Button Button1;
   protected System.Web.UI.WebControls.Panel Panel1;

   private void Page_Load(object sender, System.EventArgs e)
   {
      Response.Write("WebUserControl1 :: Page_Load <BR>");
   }

   private void Button1_Click(object sender, System.EventArgs e)
   {
      Response.Write("WebUserControl1 :: Begin Button1_Click <BR>");
      OnBubbleClick(e);
      Response.Write("WebUserControl1 :: End Button1_Click <BR>");
   }

   public event EventHandler BubbleClick;

   protected void OnBubbleClick(EventArgs e)
   {
      if(BubbleClick != null)
      {
         BubbleClick(this, e);
      }
   }           

   #region Web Form Designer generated code
   override protected void OnInit(EventArgs e)
   {
      InitializeComponent();
      base.OnInit(e);
   }

   private void InitializeComponent()
   {
      this.Button1.Click += new System.EventHandler(this.Button1_Click);
      this.Load += new System.EventHandler(this.Page_Load);

   }
   #endregion

}

(BubbleClick), . , BubbleClick, EventHandler - , EventHandler, Click.

OnBubbleClick , - (BubbleClick!= null), , BubbleClick, EventArgs () . , Response.Write, .

ASPX .

<%@ Register TagPrefix="ksa" 
    TagName="BubbleControl" 
    Src="WebUserControl1.ascx" 
%>
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" 
    AutoEventWireup="false" Inherits="aspnet.eventbubble.WebForm1" 
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
    </HEAD>
    <body MS_POSITIONING="GridLayout">
        <form id="Form1" method="post" runat="server">
            <ksa:BubbleControl id="BubbleControl" runat="server" />
        </form>
    </body>
</HTML>

.

public class WebForm1 : System.Web.UI.Page
{
   protected WebUserControl1 BubbleControl;

   private void Page_Load(object sender, System.EventArgs e)
   {
      Response.Write("WebForm1 :: Page_Load <BR>");
   }

   #region Web Form Designer generated code
   override protected void OnInit(EventArgs e)
   {
      InitializeComponent();
      base.OnInit(e);
   }

   private void InitializeComponent()
   {    
      this.Load += new System.EventHandler(this.Page_Load);
      BubbleControl.BubbleClick += new EventHandler(WebForm1_BubbleClick);
   }
   #endregion

   private void WebForm1_BubbleClick(object sender, EventArgs e)
   {
      Response.Write("WebForm1 :: WebForm1_BubbleClick from " + 
                     sender.GetType().ToString() + "<BR>");         
   }
}

, InitializeComponent. , Reponse.Write, .

: , InitializeComponent, , - , .

+6

1)

2) RaiseEvent, ,

3) Init AddHandler, control.event ,

!

+2

OdeToCode, @lordscarlet . , VB, #. . , , null OnBubbleClick, VB, , , , : "... . " RaiseEvent ", ". , VB- OdeToCode CountryDropDownList.

.

<%@ Control Language="vb" AutoEventWireup="false" CodeBehind="CountryDropDownList.ascx.vb" Inherits="CountryDropDownList" %>
<asp:DropDownList runat="server" ID="ddlCountryList" OnSelectedIndexChanged="ddlCountryList_SelectedIndexChanged" AutoPostBack="true">
    <asp:ListItem Value=""></asp:ListItem>
    <asp:ListItem value="US">United States</asp:ListItem>
    <asp:ListItem value="AF">Afghanistan</asp:ListItem>
    <asp:ListItem value="AL">Albania</asp:ListItem>
</asp:DropDownList>

.

Public Class CountryDropDownList
    Inherits System.Web.UI.UserControl
    Public Event SelectedCountryChanged As EventHandler

    Protected Sub ddlCountryList_SelectedIndexChanged(sender As Object, e As EventArgs)
        ' bubble the event up to the parent
        RaiseEvent SelectedCountryChanged(Me, e)
    End Sub
End Class

ASPX .

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="UpdateProfile.aspx.vb" Inherits="UpdateProfile" MaintainScrollPositionOnPostback="true" %>
<%@ Register Src="~/UserControls/CountryDropDownList.ascx" TagPrefix="SO" TagName="ucCountryDropDownList" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
    </HEAD>
    <body>
        <form id="Form1" method="post" runat="server">
            <SO:ucCountryDropDownList id="ddlCountry" runat="server" />
        </form>
    </body>
</HTML>

:

Protected Sub OnSelectedCountryChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlCountry.SelectedCountryChanged
    ' add your code here
End Sub
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Source: https://habr.com/ru/post/1697125/

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