Value cannot be null.Parameter name addresses error will occur

hi,
  
   Thanks for the solution.

First thing first, always remember to check for NULL value in case of Query String or Session or any State Mgmt tech you are using.

 

It can be done with the help of code as below

if (Request.QueryString["Name"] != null)

            {

           

            }

 

You can also do one thing

In Code file use a function like this

 

private string ReturnComMailID(string ComMailId)

        {

            string _comMailId;

            if (ComMailId != null)

            {

                _comMailId = ComMailId;

            }

            else

            {

                _comMailId = "";

            }

            return _comMailId;

        }

 

And in Design file use this function like the code below

 

<asp:Label ID="Label1" runat="server" Text='<%#ReturnComMailID(Convert.ToString(Eval("Name")) %>'>asp:Label>

 

By this means you can easily validate the values.

Happy coding.

 

From

Abhishek Dikshit

 

Mark the post as Answer if it helped you.

try changing like this. Also explain how the value get retrieved on page.

 "'mail.aspx?mailid=<%#Eval("cmpnymailid")%>' id="a1">Apply Here"

hi,

   already i  passed the values from .aspx page to .aspx.cs page in my project they are all works well,

mailid1 = Request.QueryString["mailid"]; 

the request.querystring can get the value from mailid but it couldn't assign the value to mailid1,the mailid1 shows null value so only the error will occur,

but i dont know why Request.Querystring cannot assign the value to mailid1.  

Krithi querystrings are used to passed value between pages. You are trying to use the value passed from .aspx page in .aspx.cs file. .aspx.cs is code behind file how you can pass the value to that page.
Queristring generally we use to pass value from one page to another page.