I have a website and say a user comes along and fills out the form with bogus data. Then after he fills it out, he enters another one and another one and another one of bogus data. He's basically just trying to clog up the data base.
How is the best way to combat this? Would it make sense to when they submit the data track the IP address?
I have been struggling to find a solution for this problem. What I need to do is build a server application that accepts tcp client requests from different clients running on same port say:1003. I experimented by using asynchronous mode call backs etc. but it disconnects once connection is established and does not respond for further requests from the same client.
View 1 Repliesexplain to me how listening to ARP requests in VB.net or C #?
View 2 RepliesI recently found myself in a thread deling with convertions from decimal number to fractions... Being a bit too brusk and dismissing the idea at first.I have now implemented a structure based on code frm Javelia whithc can be seen in this thread.Solitare also proveided code that I eventually understood and was working.[URL]...it a step longer and developed a structure that can also implement calculating with fractions... My first try is also posted in the tread above...
The implimentation is far from perfect, as it does not deal with POW of fractions.. So if anybody has some ideas on hoe to do this with squer root and all pleas let me know and Ill update the code..
[Code]...
So I am making a file crypter so that I can encrypt my VB.NET Application that I am making so that people can't decompile it. I had made this in C# and am transfering it to VB.NET, Everything worked fine in C# but once I had re-written the code in VB.NET i get this error inside of my RC4 Encryption method:
'Arithmetic operation resulted in an overflow.'
The error is occuring here:
Dim t As Int64 = (s(i) + s(j)) Mod 256
This is the same code above in c#:
int t = (s[i] + s[j]) % 256;
Is there anyway to make that calculation with it erroring? And why does it work in C# but not VB.NET?
I have a function called Modify. It is delcared like so:Public Function Modify(Of SIMType As {New, DAOBase})(ByVal obj As DAOBase) As Boolean
You can see that this function is generic. It takes as a paramer a object that is a DAOBase or subclasses of DAOBase.Inside the modify function there is a call like so:
DAOToGP(obj)This is where the polymorphism comes into play. There are four or so subclasses I have created of DAOBase. I have written a DAOToGP() for each of these types. So in the Modify() function, when it calls the DAOToGP(obj), polymorphism should kick in and it should call the correct implementation of DAOToGP() depending on the type that I pass into Modify().
However, I get the following error:Error 20 Overload resolution failed because no accessible 'DAOToGP' can be called without a narrowing conversion:'Public Shared Function DAOToGP(distributor As Distributors) As Microsoft.Dynamics.GP.Vendor': Argument matching parameter 'distributor' narrows from 'SierraLib.DAOBase' to 'IMS.Distributors'.'Public Shared Function DAOToGP(product As Products) As Microsoft.Dynamics.GP.SalesItem': Argument matching parameter 'product' narrows from 'SierraLib.DAOBase' to 'IMS.Products'. C:Usersdvargo.SIERRAWOWIRESDocumentsVisual Studio 2010ProjectsSIMDev_2SIMIMSDVSIMLibGPGPSIMRunnerRunnersRunnerBase.vb 66 39 IMS
I am kind of at a loss here. I am not sure why it cant figure out which function to call.
my code works fine in JavaScript but doesn't work correctly in Firefox or safari and wondering why. What I'm doing is I have a loop going through each element and depending on the variable inside a text box just want to alert something. Like i said earlier this code works fine in IE. Here is the code below:
Here is an example of text box:
<asp:TextBox ID="txtMac" runat="server" req="yes" errMessage="Mac"/>
for (a = 0; a < theForm.elements.length; a++) {
if (theForm.elements[a].type == "text" && theForm.elements[a].req == "yes") {
alert("Made it here")
}
}
Problem dealing with apostrophe in filter?
View 5 RepliesI've been messing around with prime numbers for a while now, but I now want to use massive numbers, say a few million digits in length. Is there a way of storing and performing mathematical functions with such large numbers? Is it even possible on my home computer? I read on another old thread, something about a big number library, but the links he gave are now dead.
View 4 RepliesI sure this has been asked more then once... New to vb.net and I have been experimenting with a datetimepicker and how it looks at and deals with time. What I am trying to do is to add up my time (not worried about the date at all). I have it figured out and can get it to work so long as I do not go over 24 hours... and that is where my issue comes into play.
How do I display my total time in hours once it has gotten over 24 hours ( I do not want days.. just hours) for instance, a 40 hour work week, not 1 day and 16 hours.
[Code]...
A partner of ours is making a call to a web service that includes a parameter called token. Token is the result of an MD5 hash of two numbers, and helps us authenticate that the user using our partners system. Our partner asks the user for two strings, concatenates them, runs them through MD5, and then calls our web service. The result of the MD5 is the token, and it is submitted to us as a string.
We store valid tokens in a DB - since we use the SQL Server to compute the tokens on our end, SQL seemed to be happiest storing the tokens as a varbinary, which is its native result for an MD5 computation.
We have two pieces of code that attempt to do the same thing - run a select query that pulls out a value based on the token submitted. One uses a dynamic query (which is a problem), but it works. The other one attempts to do the same thing in a parameterized (safer) fashion, it does not work - it is unable to locate the token.
Here's the two competing attempts. First, the parameterized version which fails:
byteArrayToken = System.Text.UnicodeEncoding.Unicode.GetBytes(stringToken)
scSelectThing.CommandText = "select thing from tokenstable where token=@token"
Dim param As SqlParameter = scSelectThing.Parameters.Add("@token",
[Code].....
I'm writing a web crawler for a specific site. The application is a VB.Net Windows Forms application that is not using multiple threads - each web request is consecutive. However, after ten successful page retrievals every successive request times out. I have reviewed the similar questions already posted here on SO, and have implemented the recommended techniques into my GetPage routine, shown below:
[Code]...
i am creating a httpRequest handler to download files my question is which better to use aspx or ashx ?
View 3 RepliesI'm wanting to write a program in vb .net that could monitor outgoing print requests from any program on the PC, prompt the user if they would like to add a header to the document, and if they say yes, then tack it on (if the user has printed something in the space where the header will go, just print on top of it). Is this possible? I've looked around for ideas on how to do this, but I can't seem to find anything.
View 1 Repliesthis is general to any operation calling an SQL server, or anything requiring an open connection at that.
Say I have anywhere from 20 to 1000 Select calls to make for each item in data being looped. For each step, I'll select from sql, store data locally in a struct, then proceed. This is not a very expensive call, so should I keep the connection open for the entire loop? Or should I open and close every step?
How expensive in run time is opening a connection? I would think it'd be better to keep the connection open, but would like to get the correct response for this.
while using HTTP web Requests, when i try and read the stream i always get an error saying 403 Forbidden but if i try to do it in the VB.Net web browser it works fine. Here is my code:
Imports System.Net
Imports System.Text
Imports System.IO
[Code]....
I have a server making a head request to a database dump I've created. The remote server does this to make sure that it's not using excessive bandwidth when not necessary.However, due to some other circumstances outside my control this causes the script to be hit twice: once for the head request, and then another time to download the data.
What I'd like is to have the script I've written detect the head request, send back a couple of headers (e.g. last modified is right now, filesize different than before), and exit. Is there a way to do this?
I have a server making a head request to a database dump I've created. The remote server does this to make sure that it's not using excessive bandwidth when not necessary.However, due to some other circumstances outside my control this causes the script to be hit twice: once for the head request, and then another time to download the data.
View 1 RepliesI have a web service I'm trying to interface with however no matter what I try it is refusing to send the clients credentials along with the request.The security block in my app.config looks like
<security mode="Transport">
<transport clientCredentialType="None" proxyCredentialType="None" realm="" />
<message clientCredentialType="UserName" algorithmSuite="Default" />
[code].....
Some tables I am dealing with have null values and are throwing errors. So far ive tried a few solutions to deal with the nulls with no success.Here are the code samples from my efforts so far;
If (r("datemodified").Equals(DBNull.Value)) Then
datemodified = String.Empty
Else[code]....
i have ran the query and it is working ok (i.e all the cols exist)
Dim myreader As SqlDataReader = cmd.ExecuteReader
'read information from the database and give the values to the arguments(column_1, and column_2)
While myreader.Read
column_1 = myreader.GetString(1)
column_2 = myreader.GetString(2)
.....
I get an error when the data returned from myreader.GetString(2) is NULL. How do I check for nulls before assigning column_2 a value?
I'm trying to test a varbinary(max) field to see if it's null. I'm trying to figure out if it's a null or not in the select statement, hoping to avoid having to do this locally for every row of the returned dataset. This is the SQL I'm using,
[Code]....
Is there any way to convert null terminated string to normal string.I mean I can easily make a program to find the location of vbnull but there has to be a built in function for that.
View 15 RepliesSome tables I am dealing with have null values and are throwing errors. So far ive tried a few solutions to deal with the nulls with no success.
Here are the code samples from my efforts so far;
If (r("datemodified").Equals(DBNull.Value)) Then
datemodified = String.Empty
[code].....
Is it possible to translate the following C# code into VB.NET, using VB 9.0?
delegate Stream StreamOpenerDelegate(String name);
void Exec1()
{
WorkMethod( x => File.OpenRead(x));
[CODE]...
Can I do something like this?:
Private Delegate Function StreamOpenerDelegate(ByVal name As String) As Stream
Private Sub WorkMethod(ByVal d As StreamOpenerDelegate)
''
End Sub
[CODE]...
I'm trying to write some documentation, but I don't know VB syntax. Often I use Reflector to translate it, but I'm not sure it's working in this case. I'm also not clear on where I would need line continuation characters. In VB9, it's not possible to have multi-line lambdas (or Sub lambdas, which I did not ask about). In VB9, all lambdas return a value, and must be a single expression. This changes in VB10. VB10 will allow the above syntax, but VB9 will not. In VB9, if the logic involves multiple code lines, it must not be a lambda; you must put it into a named Function and reference it explicitly.
Like this:
Private Delegate Function StreamOpenerDelegate(ByVal name As String) As Stream
Private Sub WorkMethod(ByVal d As StreamOpenerDelegate)
''
End Sub
[CODE]...
I am using a stored procedure to fill a dataset with a large amount of data (47k rows and 8 columns). I am needing to fill two tables with the results of this stored proc.One table will have data representing 47k reps that currently have credit for a transaction. The other table will be a mirror copy of the 1st table with 47k reps that were supposed to get credit for a transaction. This application is going to take credit from one rep. and give the credit to the other rep record in the 2 mirrored datasets. It's taking 30 seconds for the data adapter fill method to return records to my application. I would like to reduce the amount of time it takes for this request to process.
[Code]...
1. I having a project dealing with MsAccess database.
2. Currently the project connect the db using table adapter/data adapter method.
3. When I called a Me.SubjectCourseTableAdapter.Fill(Me.ProgrammingDataSet.Subject_Course) at frmCourse, it return me error message "System. NullReferenceException was unhandled Message="Object reference not set to an instance of an object.""
4. This line of code is just the same at frmA. Wonder why it will cause error at frmB.Besides, which is the better way to connect access? data adapter or ado.net?
I want a method of dealing with very, very, very big numbers (potentially a million digits). It is very cumbersome to deal with very big numbers in VB, would another language perhaps be better for that?
View 10 RepliesI have a main form which contains a few buttons...some of those buttons open up smaller forms...there is also a button for each of those smaller forms, which should let me bring the chosen form to the front and give it focus...basically like the tabs in your task bar let you switch between which program you are using...but I'm having trouble with this...I need to click the button 2 times before the form I want comes to the front...the first click removes focus from the currently activated form the second click then moves the form I want to the front.I need this to happen in one click..I[code] figured out the exact cause of the problem.it's due to the fact that the first click doesn't actually take effect since the child form has focus...so the first click actually just transfers focus to the main form...the second click does what it should.I knew it was going to be extremely obvious.so the question now becomes...how can I overcome this if that is possible at all...I know I've seen applications where I can still activate functions of the parent form in one click even if I have a child form open and focused.And it's basically what I need...it does what I want and lets me switch between child forms in one click...but it stuffs up the entire look of my parent form...the layout and colors get wacky...the transparency of certain things don't seem to work and my background image is gone..
View 7 RepliesI have a site developed using vb.net 2.0. It has a URL of like [URL]..I want to avoid any malicious requests using other URLs. I have tried to implement using the code below and would like to kick such requests out of the site on the page load. How can I achieve this?
If (urlParams.Contains("http") And
Not urlParams.Contains(Request.ServerVariables("HTTP_HOST").ToString)) Then
Would like to kick out of the site here.
End If
