What is AutoEventWireup?

When I created zipsearch.aspx file, the following
code was generated:
<%@ Page Language="vb" AutoEventWireup="false" Codebehind="zipsearch.aspx.vb" Inherits="ZipcodeDB.zipsearch"%>

What is AutoEventWireup? - what is the effect is set to true or false?

Thanks

Re: What is AutoEventWireup?

Hi,

this is taken from the MSDN library:

the ASP.NET page framework also supports an automatic way to associate page events and methods. If the AutoEventWireup attribute of the Page directive is set to true (or if it is missing, since by default it is true), the page framework calls page events automatically, specifically the Page_Init and Page_Load methods. In that case, no explicit Handles clause or delegate is needed.

The disadvantage of the AutoEventWireup attribute is that it requires that the page event handlers have specific, predictable names. This limits your flexibility in how you name your event handlers. Therefore, in Visual Studio, the AutoEventWireup attribute is set to false by default and the designer generates explicit code to bind page events to methods.

If you do set AutoEventWireup to true, Visual Studio will generate code to bind the events and the page framework will automatically call events based on their names. This can result in the same event code being called twice when the page runs. As a consequence, you should always leave AutoEventWireup set to false when working in Visual Studio.

Resource: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/vbconWebFormsEventModel.asp

Grz, Kris.

Re: What is AutoEventWireup?

Try a lookup in Visual Studio Help->Index. It will tell you all that you want to know about it, and then some.

NC...

Re: What is AutoEventWireup?

To explain it a lil more

If you know VB then remeber what happens if you double click on a button in "desing time" in the code an event procedure

Button_click( ) would come up for you to enter the code.

This is a classic feature of Auto event wireup - and in VB you had to live with it.

But in .NET you can name the event handling function whatever you want and tie up the event with the corresponding handling function.

So if you have a button you could call the MyNewButton_click( ) function. But for this to be possible the "Auto Event Wire-up" property must be set to false at the page level.

Hope this helps [:)]

Re: What is AutoEventWireup?

I'm very new to ASP.NET, so correct me if I am wrong, but I don't think it matters whether AutoEventWireup is true of false, you can still name your event handling functions whatever you want.

Eg. in your .aspx file you can have something like:

[code] [/code]

And in your CodeBehind(.aspx.cs) have

[code] protected void dance_monkey_dance(object sender, System.EventArgs e){ //Stuff } [/code]

Note that the handling function has to be protected, not private, as it is referenced in the markup. However, for AutoEventWireup to work, you still have to use the Page_Load and Page_Init names for those functions.

Cheers,
Inno

Re: What is AutoEventWireup?

Inno,

You are replying to a post that is over 2 years old? Why? For what purpose?

NC...

Re: What is AutoEventWireup?

[:S]

WOW

They really do come back from the dead (to the top of the list.)

That sucks big time, Um hello INNO read this please ALL of it >>>> Getting Started

Re: What is AutoEventWireup?

NC,

I came across this post googling "AutoEventWireup" - it is the first result on Google, so although this post may be long dead in the context of our community, that is far from being true in the wider sense. The post was useful to me, but it also contained some misinformation. I made the call to fix it, granted, at a cost to this community, but hopefully for a greater benefit to all. My sincerest apologies to anyone who didn't get an answer they needed because of this.

-Inno

Re: What is AutoEventWireup?

In that case you should start a new post.

NC...

Re: What is AutoEventWireup?

...and how would that help someone finding this page via a google search and finding mis-information contained within?

Re: What is AutoEventWireup?

I think by auto wire-up, they mean that buttons will automatically map to buttonName_OnClick. This isn't the same as explicitly declaring OnClick="buttonName_Click".

Re: What is AutoEventWireup?

Check this out... http://forums.asp.net/p/932513/1096656.aspx

Also note that the default value for aspx pages in C# is true & for VB.NET is false.

HTH

Re: What is AutoEventWireup?

Autoeventwireup has nothing to do with the button hanlders.It works only for Page Events.

for more details see the article by using link below.

http://blogs.ittoolbox.com/c/coding/archives/autoeventwireup-attribute-9312

moredotnet

Check this out... http://forums.asp.net/p/932513/1096656.aspx

Also note that the default value for aspx pages in C# is true & for VB.NET is false.

HTH

Re: What is AutoEventWireup?

I also believe that this statement: Also note that the default value for aspx pages in C# is true & for VB.NET is false. is in error as in the link that Ulfat posted, it says:

AutoEventWireup is false when we create a new web application and event handlers are automatically created. We can find this in the Initialize Component method...

NC...

Re: What is AutoEventWireup?

The best way to see the working of this attribute would be:

Declare a string variable msg as public in WebForm1.aspx.cs.
In the HTML section of WebForm1.aspx, enter the following code in the <Head> section: <%Response.Write(msg);%>

In the Page_Load, you could enter a value for the variable msg declared.Msg= We are in Page_Load();On running the application, you will get the message We are in Page_Load() [hereafter referred to as message]. Note: this is in the default case where the attribute is set to false.Now try commenting the event handler code for the Page_Load in the aspx.cs file; and set the AutoEventWireup attribute to false in the .aspx page. On running the application this time, you will not get the message.Now with the event handler code for the Page_Load in the aspx.cs file still commented; set the AutoEventWireup attribute to true in the .aspx page. On running the application this time, you will get the message.Reason: In the case where AutoEventWireup attribute is set to false (by default), event handlers are automatically required for Page_Load or Page_Init. However, when we set the value of the AutoEventWireup attribute to true, the ASP.NET runtime does not require events to specify event handlers like Page_Load or Page_Init.A thing to be kept in mind is that the AutoEventWireup attribute of the Page directive is set to true by default for the machine (check out the value of this attribute in the machine.config) but set to false by default for a .aspx page). So if it is missing, since by default it is true (i.e., at the machine level), the page framework calls page events automatically, specifically the Page_Init and Page_Load methods. In that case, no explicit Handles clause or delegate is needed.