JS window. onload load Load multiple functions and append Functions

Window. onload is often used for projects,

The usage is as follows:

Function func () {alert ("this is window onload event! "); Return ;}

Window. onload = func;

Or:

Window. onload = function () {alert ("this is window onload event! "); Return ;}

However, window. onload cannot load multiple functions at the same time.

For example:

Function T (){
Alert ("T ")
}
Function
B (){
Alert ("B ")
}
Window. onload = T;
Window. onload = B
;

Later, we will overwrite the previous one. The above code will only output B.

You can solve the problem as follows:

Window. onload = function () {T (); B ();}

Another solution is as follows:

 

Code

Function addloadevent (func ){
VaR oldonload = Window. onload; // gets the function of the previous onload event
If (typeof window. onload! = 'Function') {// determines whether the type is 'function'. Note that typeof returns a string.
Window. onload = func;
} Else {
Window. onload = function (){
Oldonload (); // call the previously overwritten onload event function ----> as I do not know much about JS, I temporarily understand that multiple functions can be loaded by overwriting the onload event function.
Func (); // call the current event Function
}
}
}

// (Complete example) use the following:

Function T (){
Alert ("T ")
}
Function B (){
Alert ("B ")
}
Function C (){
Alert ("C ")
}
Function addloadevent (func ){
VaR oldonload = Window. onload;
If (typeof window. onload! = 'Function '){
Window. onload = func;
} Else {
Window. onload = function (){
Oldonload ();
Func ();
}
}
}

Addloadevent (t );
Addloadevent (B );
Addloadevent (C );
// Equivalent to window. onload = function () {T (); B (); C ();}

 

 

 

I personally think that using implicit functions directly (such as window. onload = function () {T (); B (); C () ;}) is faster, of course, use
Addloadevent is more professional, take all the items!

 

JS window. onload append function:

 

 

Code

<SCRIPT>
If (window. attachevent) // ie: If the Browser contains window. the attachevent function uses window. the attachevent function can also be used to determine whether it is ie: If (document. all ){//..}
Window. attachevent ("onLoad", function () {alert ("add method ");});
Else // Firefox
Window. addeventlistener ("LOAD", function () {alert ("add method") ;}, true );
</SCRIPT>

 

 

 

Run alert in JS to bring up a message and solve the problem.

============== Related materials ==========================

Attachevent binds a specified function to an event so that the function is called whenever the event is triggered on an object.

Internet Explorer provides an attachevent from 5.0
You can assign multiple processing processes to an event. Attachevent is also applicable to opera. However, Mozilla/Firefox
This method is not supported. However, it supports another addeventlistener method, which is similar to attachevent.
It is also used to assign multiple processing processes to an event. However, there are some differences between the events they are assigned. In the attachevent method, an event starts with "on" and
In addeventlistener, the event does not start with "ON". In addition, addeventlistener has a third parameter. Generally, this parameter is set to false.
You can.

Finally, I would like to thank Lei xiaobao, author of The vform verification program.

This article from the csdn blog, reproduced please indicate the source: http://blog.csdn.net/chenlei65368/archive/2009/09/12/4544823.aspx