Looping through a request.querystring in VB.NET

Question

I am trying to loop through a query string and pull out certain values as in:

?ProductID=1234&ProductID=4321&Quantity=1

For each value next to ProductID I want to execute some logic. But I am not sure how to get to the values. Any ideas?

Answer 1

sQS = Request.QueryString
For Each eItem in Split( sQS, "&" )
sName = Left( eItem, Instr( eItem & "=", "=" ) - 1 )
Response.Write sName _
& " = " & Request.QueryString( sName ) _
& "<br>"
Next

grabbed that here.. http://bytes.com/groups/asp/158709-loop-round-all-querystring-parameters

Answer 2

Try this one. Only works in VB9.

Dim queryString = GetQueryString()
queryString = queryString.SubString(1) 'Remove ?
Dim ids = queryString. _
  Split("&"c). _
  Select(Function(x) x.Split("="c)). _
  Where(Function(x) x(0) = "ProductId" ). _
  Select(Function(x) x(1))

Answer 3

Here is some untested psuedo code that should work for the code behind on the page. I hope this helps.

dim key as string
dim list as new arraylist()
for each key in Page.Request.QueryString.Keys
 if key = "ProductID" then
   list.add(Page.Request.QueryString(key))
 end if
next key

' do somthing with the list of product id's

Answer 4

Dim productID = Request.Querystring("ProductID");
Dim quantity = Request.Querystring("Quantity");

Answer 5

When your query string has more than one value with the same key you can use the NameValueCollection.GetValues method which returns a string array:

dim productID as string
for each productID  in Page.Request.QueryString.GetValues("ProductID")
  ' do something with productID
next productID