I have a question about disable button (C#) that I need your help.
in Asp.net (C#), disable the button code:
Button btn = new Button();
btn.click += new EventHandler(btn_click);
btn.Enabled = false;
btn.UseSubmitBehavior = false;
The generated HTML:
<input type="button" disabled="disabled">
The button is disabled until I use firebug and remove the 'disabled' property and change the type property to submit (<input type="submit">) then user can click on btn and it can perform btn_click method(postback).
How could we prevent this issue? I try to use CommandName (disable, enable) to mark disable button and inside btn_click method, I check if CommandName== "disable" then stop the function but it is very messy.
Thanks for your help.
Van
Client can remove the Disabled attribute but cannot change the control ViewState. On server side you can do that:
protected void btn_Click(object sender, EventArgs e)
{
if (btn.Enabled)
{
// do something
}
}
<asp:Button ID="btn" runat="server" Enabled="false" OnClick="btn_Click" Text="Test" />
You can't control your users' behavior.What you need to do is handle these things in server-side..
you can judge the button's status in btn_click.. and then do some work
#bystander is right. You need to check on the server whether that condition is correct. You can't rely on the client being 100% fool proof, and that's the exact reason why.
Can you hide the control instead, and reenable it on some future postback? Hiding doesn't actually render the control to the client at all.
Related
My c# web application has 2 panels. 1st panel is to enter some text.
The 2nd panel only shows after the 1st panel passes validation and the continue button is clicked.
The 2nd panel has a text box with 4 validations, a dropdown list box and a Submit button.
If the validation is good and the user clicks on he Submit button, I would like the Submit button to be disabled and change it's text to "Please wait..." to prevent the user from double clicking it.
I'm new to .NET so any help is greatly appreciated.
protected void BTNSubmit_Click(object sender, EventArgs e)
{
if (Page.IsValid)
{
BTNSubmit.Text = "Please wait...";
BTNSubmit.Enabled = false;
DoSomething();
}
}
This is something you will need to trap on the front end with javascript and asp.net's onclientclick attribute (which translates to javascript's onclick.)
An important key is that if your onclientclick returns false, your server event won't fire (which is what you want for the second click)
var submitted=false; //javascript variable to store if we have clicked submit yet
function ClientSubmit(obj){ //obj is your button
if(submitted) {return false;} //return false prevents server onclick from firing
submitted=true;
obj.value='Please Wait...';
obj.disabled = true;
return true;
}
Now the next time you click, your javascript will see that submitted is set to true, so this function will return false, and prevent the server event from firing
To implement this on your .aspx page
<asp:Button id="myButton" runat="server"
onclick="BTNSubmit_Click" onclientclick="return ClientSubmit(this);" Text="Submit"/>
I am dynamically adding a RadioButtonList in the Code Behind. I want it so that the 'OnClick' does not call JavaScript, but instead it calls a method in my code behind.
Is this possible?
In addition, is there a way to set it up so that this say control has runat="server"?
You can use the Button Click Event
https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.button.click(v=vs.110).aspx
Yes, it is possible. Also, there is no need to have runat="server" since your are creating the control in code.
You need to set your RadioButtonList object's OnSelectedIndexChanged event. As #Robert mentioned, if you are creating controls dynamically you need to wrap them in the Page_Init().
protected void Page_Init(Object sender, EventArgs e) {
RadioButtonList radiobuttonlist = new RadioButtonList();
radiobuttonlist.SelectedIndexChanged += radiobuttonList_CheckedChanged;
//Set the AutoPostBack to true proptery to that the user action
// will immediately post-back to the server
radiobuttonlist.AutoPostBack = true;
}
private void radiobuttonList_CheckedChanged(object sender, EventArgs e) {
//Code you want to execut when a user selects a different item
}
Reference: https://msdn.microsoft.com/en-us/library/System.Web.UI.WebControls.ListControl.SelectedIndexChanged(v=VS.110).aspx
Be sure to add the control in the Page_Init() portion of the code, not in Page_Load() or later. Set up the event handler += line inside the Page_Init() setup. The control should run server side if you do this. I'm not sure if runat="server" will be explicitly set but the control will behave that way.
I have a button and I want to stop post back whenever someone clicks on that button.
I don't want to use return false like this
<asp:Button runat="server" Text="Click" OnClick="Unnamed1_Click" OnClientClick="javascript:return false;" />
I want to stop it from code behind.
I want to create a div and some content inside the div , so when ever someone click on that button another div will be created with it's contents, but the problem is when I click the button and a post back happen , it remove the first div and construct the second one and so on
Something you can do is to disable your button after a user click on them it also disable the postback behaviour and prevent future postback, in this way
protected void Unnamed1_Click(object sender, EventArgs e) {
YourButton.Enabled = false;
}
I have a c# asp.net registration form , but i'm unable to use the reset button to achieve the objective I want. Upon clicking the reset button, the validators I have demand that I fill up ALL textboxes before I can reset the fields.
If a user were to fill up half of the form and use the reset fields, the reset button does not achieve the objective I want it to, as all textboxes have to be filled.
The codes I'm using are as follows:
protected void resetButton_Click(object sender, EventArgs e)
{Response.Redirect(Registration.aspx);}
Since this looks like Asp.Net Web Forms, as opposed to MVC, On the aspx file where you set up the button, set the CausesValidation property to false.
Link: http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.button.causesvalidation(v=vs.110).aspx
Example:
<asp:Button CausesValidation="False" />
Add this to the server-side handler of the reset button:
Response.Redirect("~/Registration.aspx", true);
you can clear the modelstate on the controller. ModelState.Clear();
I'd like to instantly disable a Button after clicking it, so a User can't click it twice in short succession and fire the OnClick_Event twice in a row. btn.Enabled = false doesn't seem to do the trick instantly. Is there any other way to accomplish this?
Thanks,
Dennis
What you are doing is disabling it after a post back therefore your button will be disabled in the page that's rendered when the browser receives the response.
Do it on the client-side with JavaScript instead:
var button = document.getElementById('yourButton');
button.disabled = true;
If you're facing issues with posting back to the server, check out this article: How to disable an ASP.NET button when clicked.
function disable()
{
var button = document.getElementById('<%= Button1.ClientID %>');
button.disabled = true;
}
<asp:Button ID="Button1" OnClientClick="disable();">
you can achieve this via javascript
function Disable(btn)
{
btn.disabled = true;
}
and add this to your button OnClientClick="javascript:return Disable(this);"
You can handled it simply by this code.Suppose, here is a button named btnAdd.When you click this button it will be disable due to execute it's corresponding code.I mean due to post back it will be disabled.
if (!IsPostBack)
{
btnAdd.Attributes.Add("onclick", "this.disabled=true;" + GetPostBackEventReference(btnAdd).ToString());
}
Write the btn.Enabled= false at the end of all the functionality in the Onclick Event of the Button. It will do the Required action.
Disabling the button has raised on problem. You won't get the server side event fired. So better seek the alternative by hiding the button (and yes displaying some friendly error message 'working', 'processing' etc.). The work out on how to disable asp.net button on postback would help. Thanks.
YourButton.Enabled = false;
if(!YourButton.Enabled)
{
\\Your Code Here
YourButton.Enabled = true;
}
Hope this helps ;)