Make a checkbox checked or unchecked based on the value?

Question

How can we make a checkbox checked or unchecked programatically based on the value? That is to say, for a particular user if the value is true, the checkbox should be checke

Answer 1

if(condition = true)
{
@Html.CheckBoxFor(x => x.Test, new { @checked = "checked" })
}
else
{
@Html.CheckBoxFor(x => x.Test)
}

Hope this helps :)

Answer 2

If you want to check/uncheck check box value in code-behind, you have to include an ID and runat server attributes in your check box tag.

<checkbox Id="chk" runat="server" class="chkbox"/>

code-behind:

if(yourcondition==true)
  chk.checked = true;
else
  chk.checked = false;

If you want to do it in javascript

<checkbox Id="chk" class="chkbox"/>

JS:

if(yourcondition==true)
  chk.checked = true;
else
  chk.checked = false;

Answer 3

If you're using MVC and passing in model values correctly from your controller, then

@Html.CheckBoxFor(model => model.checkBox1)

...is all you need. The html-helper does the logic to figure out whether or not to insert the checked="checkbox" code.

Otherwise, without the HTML-helper you can dynamically generate the attribute yourself (others have pointed out how), but don't make the mistake of thinking that checked = "" will leave the box unchecked. See this answer for an explanation.

Answer 4

if(condition = true)
{
@Html.CheckBoxFor(x => x.Test, new { @checked = true })
}
else
{
@Html.CheckBoxFor(x => x.Test)
}

Answer 5

There is a simpler way to include or not include the checked attribute if you are writing our your own <input> instead of using alternatives such as Html.CheckBoxFor:

<input type="checkbox" checked="@isChecked">

Razor is smart enough to automatically generate either

<input type="checkbox" checked="checked">

or

<input type="checkbox">

depending on whether isChecked is true or false. No need for if statements or duplicate code.

Answer 6

If you do not want to use @Html.CheckBoxFor for whatever reason and you'd like to stick to

         <input type="checkbox"> 

then this is what I found to be the best way to do it:

 <input @(Convert.ToBoolean(Model.YourPropertyHere) == true ?   "checked='checked'" : string.Empty)  type="checkbox" />

The code that @Yasser provided above:

    checked="@(required ? "checked" : "")"

Did not work for me because it was still adding the checked attribute to the element, and setting checked="" will still render the check box as checked, which was not the desired output, instead if you wrap the whole statement into a razor block like so:

     @(Convert.ToBoolean(Model.YourPropertyHere) == true ?   "checked='checked'" : string.Empty)

you will get the desired results.