How to set the radio button through viewbag in this way?

Question

User-1651604128 posted

In my asp.net razor view, I have this radio button codes, this is the Edit razor view, so when the razor is opened, I want the radio button selected based on the ViewBag returns from controller, from the debug, I can see the ViewBag returns value properly

 <div class="radio1" style="display: inline-block; white-space: nowrap;">
                            <input id="select1" disabled type="radio" name="IN_TYPE" value="1" checked = @(ViewBag.INType =="1") >US
                            <input id="select2" disabled type="radio" name="IN_TYPE" value="2" checked = "@(ViewBag.INType == "2")">Canada
                            <input id="select3" disabled type="radio" name="IN_TYPE" value="3" checked = "@(ViewBag.INType == "3")">France
                            <input id="select4" disabled type="radio" name="IN_TYPE" value="4" checked = "@(ViewBag.INType == "4")">International
                        </div>

But I got run time error:

An exception of type 'Microsoft.CSharp.RuntimeBinder.RuntimeBinderException' occurred in System.Core.dll but was not handled in user code

Additional information: Operator '==' cannot be applied to operands of type 'System.Collections.Generic.List<System.Web.Mvc.SelectListItem>' and 'string'

and the above error highlighted with the line code of "<input id="select1" disabled type="radio" name="IN_TYPE" value="1" checked = @(ViewBag.INType =="1") >US "

It seems this code "@(ViewBag.INType =="1")  does not compile properly,

any idea how to fix it, much appreciated,

Answer 1

User475983607 posted

The error indicates you set the ViewBag.INTType to System.Collections.Generic.List<System.Web.Mvc.SelectListItem> type most likely in the Action.  That bit of code is not shared.  For some reason you are trying to compare a List<System.Web.Mvc.SelectListItem> to a string in the View.  

IMHO, you need to organize your thoughts and rethink the approach.

Lastly, I recommend using the RadioButtonFor extension as it will automatically handle the selection.

https://docs.microsoft.com/en-us/dotnet/api/system.web.mvc.html.inputextensions.radiobuttonfor?view=aspnet-mvc-5.2

https://stackoverflow.com/questions/3114689/when-using-net-mvc-radiobuttonfor-how-do-you-group-so-only-one-selection-can

 

Answer 2

User1520731567 posted

Hi Peter Cong,

Additional information: Operator '==' cannot be applied to operands of type 'System.Collections.Generic.List<System.Web.Mvc.SelectListItem>' and 'string'

According to your error message,it means that different types can't assign values to each other.

You could modify like: (If you make sure the number of radio buttons)

<div class="radio1" style="display: inline-block; white-space: nowrap;">
    <input id="select1" disabled type="radio" name="IN_TYPE" value="1" checked=@(ViewBag.INType.Items[0].fieldName== "1")>US
    <input id="select2" disabled type="radio" name="IN_TYPE" value="2" checked="@(ViewBag.INType.Items[1].fieldName== "2")">Canada
    <input id="select3" disabled type="radio" name="IN_TYPE" value="3" checked="@(ViewBag.INType.Items[2].fieldName== "3")">France
    <input id="select4" disabled type="radio" name="IN_TYPE" value="4" checked="@(ViewBag.INType.Items[3].fieldName== "4")">International
</div>

Best Regards.

Yuki Tao

Answer 3

User-1651604128 posted

Hi Yuki,

thanks a lot for your help, I tried your codes, unfortunately it shows error of "Items" can not be found.

but when I tried your codes, I found the problem is that I used the wrong viewbag, the ViewBag.INType is the list of items (no sure why I can not identify the Items), I should use another viewbag.PRO_Type which is the specific string item

this is the working code <input id="select1" disabled type="radio" name="IN_TYPE" value="1" checked = @(ViewBag.PRO_TYPE == "1") >US