error - passing array value to viewdata MVC5

Abhilash J A

9y1.2k.NET

Hello everyone,

This is the Controller,

string[] arryvalidvalue = new string[] { "Red","Black","White" };
List listValidValies = new List();
foreach (var item in arryvalidvalue)
{
listValidValies.Add(new SelectListItem { Text = item, Value = item.ToString() });
}
ViewData["arryvalidvalue"] = listValidValies;

and view,

<tr><td>@Html.TextBox(item.AttributeName)td><td>@Html.DropDownList("", ViewData["arryvalidvalue"] as List<SelectListItem>, "Select", new { size = item.AttributeMaxLength })td>tr>

error occured:

An exception of type 'System.ArgumentException' occurred in System.Web.Mvc.dll but was not handled in user code

Additional information: Value cannot be null or empty."

How can I solve this?

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Chetan Ranpariya9y ago
Accepted answer
Error is not because of the data or arraylist.

Error is because you are passing blank string in the first argument of "@Html.DropDownList".

Try to change
<td>@Html.DropDownList("", ViewData["arryvalidvalue"] as List<SelectListItem>, "Select", new { size = item.AttributeMaxLength })td>tr>
to
<td>@Html.DropDownList("DropDownList1", ViewData["arryvalidvalue"] as List<SelectListItem>, "Select", new { size = item.AttributeMaxLength })td>tr>
This should resolve your issue.
Abhilash J A9y ago
Hello Chetan,
Ok sir, I will try and replay you.

Thank you.
Chetan Ranpariya9y ago
Hi,

I was able to run your code.
I got ArgumentException when call @Html.DropwDownList with blank string in the first argument.

So I changed it to
@Html.DropDownList("Dropdownlist1", ViewData["arryvalidvalue"] as List, "Select", new { size = 1 })
And it started working. Only thin I changed is the setting "size" to "1" instead of "item.AttributeMaxLength" because I don't know what is "item".
Abhilash J A9y ago
Hello, Chetan . I have also tried that. But still that error rising. Please help me .
Abhilash J A9y ago
I want to bind the arraylist values to the dropdown. So here arraylist object carring data. Then why this error here?
Chetan Ranpariya9y ago
Hi,

The first argument to @Html.DropdownList is The value to assign to the name attribute of the dropdown list.

The exception you are seeing is because you are passing blank string ("") to it.

You pass a valid name for the dropdown list in @Html.DropdownList and it should resolve your issue.

https://msdn.microsoft.com/en-us/library/gg548304(v=vs.111).aspx

Thanks and regards,
Chetan Ranpariya