Devexpress Aspxgridview Callback

aspxgridviewcallbackdevexpress

Hi guys i have a problem.

Im making a callback from an aspxgridview. I do callback when i make RowDblClick and then i switch to another tab of the pageControl and fill some controls with database information. One of those controls is another gridview. So what i want to do is when i rowdblclick in the new gridview, make another callback.

I dont know why but when i double click the new aspxgridview, my application stacks. So i haven't response of the callback. I stopped the first callback of the first grid, and the second callback works fine.

So my question is, how can i make a callback in an aspxgridview by a rowdblclick, and after that make another callback with another rowdblclick in another aspxgridview?

this is first aspxgridview

<dx:ASPxGridView ID="grillaInformes" runat="server" KeyFieldName="ID" width="100%"        EnableCallBacks="false" ClientInstanceName="grillaInformes" OnCustomCallback="grillaInformes_CustomCallback">
                    <ClientSideEvents RowDblClick="function(s, e) { s.PerformCallback(e.visibleIndex); }"/>

and this is the second aspxgridview, whose callback doesn't work because i made another callback before of grillaInformes

<dx:ASPxGridView ID="grillaSubInformes" runat="server" KeyFieldName="ID"  Width="100%" EnableCallBacks="false" ClientInstanceName="grillaSubInformes" OnCustomCallback="grillaSubInformes_CustomCallback"  >
                       <ClientSideEvents RowDblClick="function(s, e) { s.PerformCallback(e.visibleIndex); }"/>

Best Answer

Have you tried calling a defined JavaScript function for the CallBacks, and stepping through the code there? For example:

function grillaInformes_RowDblClick(s, e) {
    s.PerformCallback(e.visibleIndex);
}

function grillaSubInformes_RowDblClick(s, e) {
    s.PerformCallback(e.visibleIndex);
}

and use the following for your grid:

<dx:ASPxGridView ID="grillaInformes" runat="server" KeyFieldName="ID" width="100%" EnableCallBacks="false" ClientInstanceName="grillaInformes" OnCustomCallback="grillaInformes_CustomCallback">
                    <ClientSideEvents RowDblClick="grillaInformes_RowDblClick"/>

<dx:ASPxGridView ID="grillaSubInformes" runat="server" KeyFieldName="ID"  Width="100%" EnableCallBacks="false" ClientInstanceName="grillaSubInformes" OnCustomCallback="grillaSubInformes_CustomCallback"  >
                       <ClientSideEvents RowDblClick="grillaSubInformes_RowDblClick"/>

You should see right away whether the second double-click is even starting, then step through the code behind. We do things like this often though, and have no problem with multiple callbacks running at one time.

Related Solutions

A callback function

Developers are often confused by what a callback is because of the name of the damned thing.

A callback function is a function which is:

accessible by another function, and
is invoked after the first function if that first function completes

A nice way of imagining how a callback function works is that it is a function that is "called at the back" of the function it is passed into.

Maybe a better name would be a "call after" function.

This construct is very useful for asynchronous behaviour where we want an activity to take place whenever a previous event completes.

Pseudocode:

// A function which accepts another function as an argument
// (and will automatically invoke that function when it completes - note that there is no explicit call to callbackFunction)
funct printANumber(int number, funct callbackFunction) {
    printout("The number you provided is: " + number);
}

// a function which we will use in a driver function as a callback function
funct printFinishMessage() {
    printout("I have finished printing numbers.");
}

// Driver method
funct event() {
   printANumber(6, printFinishMessage);
}

Result if you called event():

The number you provided is: 6
I have finished printing numbers.

The order of the output here is important. Since callback functions are called afterwards, "I have finished printing numbers" is printed last, not first.

Callbacks are so-called due to their usage with pointer languages. If you don't use one of those, don't labour over the name 'callback'. Just understand that it is just a name to describe a method that's supplied as an argument to another method, such that when the parent method is called (whatever condition, such as a button click, a timer tick etc) and its method body completes, the callback function is then invoked.

Some languages support constructs where multiple callback function arguments are supported, and are called based on how the parent function completes (i.e. one callback is called in the event that the parent function completes successfully, another is called in the event that the parent function throws a specific error, etc).

Javascript – How to pass a parameter to a setTimeout() callback

setTimeout(function() {
    postinsql(topicId);
}, 4000)

You need to feed an anonymous function as a parameter instead of a string, the latter method shouldn't even work per the ECMAScript specification but browsers are just lenient. This is the proper solution, don't ever rely on passing a string as a 'function' when using setTimeout() or setInterval(), it's slower because it has to be evaluated and it just isn't right.

UPDATE:

As Hobblin said in his comments to the question, now you can pass arguments to the function inside setTimeout using Function.prototype.bind().

Example:

setTimeout(postinsql.bind(null, topicId), 4000);

Best Answer

Related Solutions

A callback function

Javascript – How to pass a parameter to a setTimeout() callback

UPDATE:

Related Topic