parsing URL ?a=b params with VB.NET from plain string - asp.net

I am using a string to store key=value pairs, it has same format as QueryString
How can I easily parse it to array? or can I somehow use interal class QueryString("paramname") to access it?

You could use the System.Web.HttpUtility.ParseQueryString, this will give you a NameValueCollection. You can then access your values easily
Dim keynameValue As String = nameValueCollection.Get("Keyname")

' parse to pairs
Dim resultarray As Array = allresultdata.Split("&")
Dim result1 As String
Dim keyvals2 As Array
For Each result1 In resultarray
keyvals2 = result1.Split()
keyvals.Set(keyvals2(0), keyvals2(1))
Next

or can I somehow use interal class
QueryString("paramname") to access it?
If you need to access querystring from another class other then page code behind, use this :
HttpContext.Current.Request.QueryString("parameterName")

String.Split() probably will work for you....

Related

Convert JSon to dynamic object in VB.Net

I am using VB.Net and calling salesforce API. It returns very ugly JSON which I am not able to deserialize. I have a following code using JSON.Net
Dim objDescription As Object = JsonConvert.DeserializeObject(Of Object)(result)
objDescription contains many properties, one on=f them in fields. But when I write something like objDescription.fields it gives me error.
objDescription.fields Public member 'fields' on type 'JObject' not found. Object
I am not very sure but I think it C# allow to convert any JSON to dynamic object. How can I use it in VB.Net?
You can turn Option Strict Off and use ExpandoObject which is recognized by JSON.NET. In order to leverage the dynamic features you can use a variable of type object.
Option Strict Off
Sub Main
Dim jsonData As Object = JsonConvert.DeserializeObject(Of System.Dynamic.ExpandoObject)("{""Id"":25}")
Dim test As Integer = jsonData.Id
Console.WriteLine(test)
End Sub
If you would like to use JObject because you need some of its features, you can index the JObject instead.
Sub Main
Dim jsonData As Object = JsonConvert.DeserializeObject(Of Object)("{""Id"":25}")
Dim test = jsonData("Id")
Console.WriteLine(test)
End Sub

How do I write a VB.Net method to filter a URLs?

I am attempting to write a method using VB.NET that will allow me to read in a URL and compare it to a list. If it is one of the URLs on the list then Bing Tracking conversion will be applied.
At the moment I can only think do write it as a comaparative method, comapring the current URL with the ones that require tracking (a list). This, however, sems a little long winded.
Each page may have a different querystring value/page id, there for its fundamental to get exactly the right page for the tracking to be applied to.
Any Ideas?
Sorry I really am a novice when developing functions in VB.Net
If I were to use th Contains() function then I would imagine that it would look a little something like this:
Private sub URL_filter (ByVal thisPage As ContentPage, brandMessage? As Boolean) As String
Dim url_1 As String = "/future-contact thanks.aspx"
Dim url_2 As String = "/find-enquiry thanks.aspx?did=38"
Dim url_3 As String = "/find-enquiry-thanks.aspx?did=90"
Dim url_4 As String = "/find-enquiry-thanks.aspx?did=62"
Dim result as String
result = CStr (url_1.Contains(current_URL))
txtResult.Text = result
End Sub
If I were to use this then what type of loop would I have to run to check all the URLs that are in my list against the current_URL? Also where would I define the current_URL?
You can use the Contains() function to check if the list contains the given value. You could also implement a binary search, but it is probably overkill for your purposes. Here is an example:
Dim UrlList As New List(Of String)
UrlList.Add("www.example2.net") 'Just showing adding urls to the list
UrlList.Add("www.example3.co.uk")
UrlList.Add("www.exampletest.com")
Dim UrlToCheck As String = "www.exampletest.com" 'This is just an example url to check
Dim result As Boolean = UrlList.Contains(UrlToCheck) 'The result of whether it was found
Make sure to add these imports Imports System and Imports System.Collections.Generic
Disclaimer: I have no experience with VB.NET

convert stringbuilder to guid

Hi I've some guids in stringbuilder and I want to store these values in guid array.
Can some one give me idea to convert this. I'm working with vb.net
Thanks in advance
Assumption: your guids are really simply strings.
Than that might help:
Dim SB as new Stringbuilder = "GUID"
Dim GuidList as New List(Of Guid)
Dim myGUID as Guid
If GUID.tryparse(SB.tostring, myGuid)=true then
Guidlist.add(myguid)
else
'Handle the error here
end if
Wrap this in a loop over your Guids, I don't know how you stored them.
Remarks: You might need to use parsexact, see the documentation: http://msdn.microsoft.com/en-us/library/system.guid.aspx
I have written out of my head, so the code might not compile...

Using ParseQueryString function to get values from QueryString

I needed to get values out of a string in a QueryString format, that is such as: data1=value1&data2=value2...
Someone suggested I used HttpUtility.ParseQueryString to get the value, I've searched and searched but I can't find any documentation or implementation of this and the Microsoft documentation for it doesn't explain how it works, can someone tell me hwat I'm doing wrong, my code is below;
Public Shared Sub ProcessString(ByVal Vstring As String)
Dim var As NameValueCollection = HttpUtility.ParseQueryString(Vstring)
Dim vname As String = var.QueryString("VNAME")
End Sub
MSDN has an example.
' Parse the query string variables into a NameValueCollection.
Dim qscoll As System.Collections.Specialized.NameValueCollection = HttpUtility.ParseQueryString(Vstring)
Dim vname As String = qscoll("VNAME")
A NameValueCollection represents a collection of associated String keys and String values that can be accessed either with the key or with the index.
I found the problem, I was referencing everything fine but I was doing it in a separate .VB dependency file, once I did it on the actual code behind of the aspx form that solved the problem and it all worked. So now I'm just passing the string from Codebehind as a specialised.NameValue collection in to the function.

dynamically change querystring in asp.net

Our client is asking to encrypt the URL because it is passing values in the query string. We have used encryption and are able to encrypt the URL; however, existing code uses querystring["var"] in so many places and fails because of the encrypted URL. Hence, on page load, we will have to decrypt the URL. If I decrypt and alter the query string using response.redirect, then again query string will be visible in the URL and can be misused.
Please help.
EDIT
I was reading about RESTfull web service. I have not yet understood entire concept. I wonder if I can use this with my application to hide query string. Please let me know if so.
Thanks.
One way to achieve this with little headache is to decrypt the query string as you currently do, then set its values to some object which can be stored in the session. Storing it in a session variable would be useful if you wanted to exclude this information (hide) from the query string - you'd essentially be passing the data around behind the scenes.
Once stored in session, you would then change your code, such that wherever you use querystring["var"], you will instead refer to the object that has been stored in the session.
Edit
Note, though, that this doesn't have to be relegated to a single value. This object can have multiple properties each representing a query string value:
MyQueryStringObject myQueryStringObject = new MyQueryStringObject(SomeUrl);
//MyQueryStringObject decrypts the query string and assigns the values to properties in its constructor
string abc = myQueryStringObject.abc;
string xyz = myQueryStringObject.xyz;
Now, that uses properties to represent each query string value. You may have tons of them. In that case, you can store the values into some sort of Dictionary or a NameValueCollection perhaps.
There are various ways to achieve this which I think is beyond topic, but, note that the key to all of this, the very essence is to simply decrypt the url on the server (during postback) and save the unencrypted data into a session variable should you want to hide it from the URL.
There is a much better way of going about this. I deal with a client with that has the same requirement. This class has soared through security scans as well.
Public Class QueryStringManager
Public Shared Function BuildQueryString(ByVal url As String, ByVal queryStringValues As NameValueCollection) As String
Dim builder As New StringBuilder()
builder.Append(url & "?")
Dim count = queryStringValues.Count
If count > 0 Then
For Each key In queryStringValues.AllKeys
Dim value As String = queryStringValues(key)
Dim param As String = BuildParameter(key, value)
builder.Append(param)
Next
End If
Return builder.ToString()
End Function
Public Shared Function DeconstructQueryString(ByVal Request As HttpRequest) As NameValueCollection
Dim queryStringValues As New NameValueCollection
For Each key In Request.QueryString.AllKeys
Dim value As String = Request.QueryString(key)
value = DeconstructParameter(value)
queryStringValues.Add(key, value)
Next
Return queryStringValues
End Function
Private Shared Function BuildParameter(ByVal key As String, ByVal value As String) As String
Dim builder As New StringBuilder()
builder.Append(key.ToString() & "=")
value = GetSafeHtmlFragment(value)
Dim encrypt As Security = New Security()
value = encrypt.Encrypt(value)
builder.Append(value)
builder.Append("&")
Return builder.ToString()
End Function
Public Shared Function DeconstructParameter(ByVal value As Object) As String
Dim decrypt As New Security()
value = decrypt.Decrypt(value)
value = GetSafeHtmlFragment(value)
End Function
End Class
Use
Dim nvc As NameValueCollection = New NameValueCollection()
nvc.Add("value", 1)
Dim builtUrl As String = QueryStringManager.BuildQueryString(url, nvc)
Response.Redirect(builtUrl, false);
Then when you get to the page you simply write:
Dim decryptedValues As NameValueCollection = QueryStringManager.DeconstructQueryString(Request)
The reason why I use NameValueCollection is because that's the same type as QueryString. You can build on to the class to add an object into the QueryString based on it's properties and their values as well. This keeps all of the complex and tedious logic encapsulated away.

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