Can I check query string is exist or not

Question

2.85/5 (4 votes)

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Hello : )

When I provide a link with query string to access another page with it, if the target page called using the link without query string I will get an error

because the query string requested

can I check the query string if exist or not during page load and do an action according to that ?

I hope my question is clear :)

thank you all :)

Posted 1-Jul-12 22:24pm

Msaya

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7 solutions

Solution 4

Yes you can. asuming the query string name is "id", and the type you are expecting is string. you can do this

C#

string s = Request.QueryString["id"] as string;

if(s != null)
{
   //you have a query string with name ID, do something
}
else
{
   //nope, there is no query string names id here, do something else
}

Posted 1-Jul-12 22:32pm

Rahul Rajat Singh

Solution 5

check the querystring length

C#

if (Request.QueryString.ToString().Length >0)
{
//Request.QueryString is exist
}

Posted 1-Jul-12 22:40pm

Prosan

Solution 7

C#

Uri uri = new Uri(Request.RawUrl);
if(uri.Query.Length>0)

Posted 16-Jul-12 0:10am

StianSandberg

Solution 1

Hi Msaya,

Sure you can. It goes something like this:

C#

using System;
using System.Web.UI;

public partial class _Default : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    string v = Request.QueryString["param"];
    if (v != null)
    {
        Response.Write("param is ");
        Response.Write(v);
    }
    }
}

Check also this post for more details.

http://www.dotnetperls.com/querystring[^]

Cheers

Posted 1-Jul-12 22:28pm

Mario Majčica

Solution 9

if (Request.QueryString.ToString().Contains("test"))
{
your code;
}

Posted 8-May-14 20:35pm

mohan lalit

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Abhinav S · Accepted Answer · 2012-07-01T22:30:00

Solution 2

HtmlPage.Document.QueryString will give you a dictionary with a list of all query string values.
If the count is 0, there is no key available.

Posted 1-Jul-12 22:30pm

Abhinav S

v2

Comments

_Amy 2-Jul-12 4:40am

Nice and effective answer as always. My +5.

Abhinav S 2-Jul-12 4:53am

Thank you.

_Amy · Accepted Answer · 2012-07-01T22:31:00

Hi,
You can try this:

C#

protected void Page_Load(object sender, EventArgs e)
{
    if(!IsPostBack){
        if (Request.QueryString["param"] != null)
        {
            //If it exists
            Response.Write(Request.QueryString["param"])
        }
        else{
            //If it is not existing
        }
    }
}

All the best.
--Amit