Prevent Users Entering Letters Instead Of Numbers?
Mar 26, 2009
The app uses several forms to let the user enter information. In each form the info is entered into textboxes and dealt with elsewhere when the "Enter" button is clicked. A lot if the info entered is used in calculations and so must not contain alpha characters, only numbers. What is the best way of examining each entry and identifying any that are not numbers, so that I can ask the user for a correction with a MsgBox?Prevent Users Entering Letters Instead of Numbers?
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Dec 20, 2010
I have a project that uses a number of DataGridView controls. Most of the cells are of the DataGridViewTextBoxCell persuasion. I declare my controls like so:Dim MyCell as DataGridViewCell Later I specify whether they are DataGridViewTextBoxControls or DataGridViewComboBoxCells like so:
MyCell = New DataGridViewTextBoxCell MyCell = New DataGridViewComboBoxCell None of the places in my code require the ability for the users to enter their own values in the Combo Boxes. That is, they are either hard-coded or the values are gathered from other data within the application.
Currently, users can highlight a combo box control defined as shown above and begin typing anything they like. For example, I have one combo box that offers the user a selection of integers between 1 and 9. I can highlight the combo box cell and enter "Hello, World!" if I'd like.What does it take to disable this ability? I'm sure there's a property, but I have yet to find it. I have searched the Internet, and have found only the ability to have user-entered values added to the list and a stream of data-binding tutorials.
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Nov 22, 2009
i want to prevent users from entering numbers and other characters such as (_,"*&^$#).... into my textbox-u know what i mean! I want my textbox to accept only alphabets. I have written a function that is able to check the numbers but i don't know how to check whether the text contains those special characters. Here is my code for the numbers. i'm sure, just as i'm able to check the numbers. i'll be able to check for those characters.
Public Function ValidateText(ByVal GetString As String) As Boolean
Dim Count As Integer = GetString.Length
Dim i As Integer
[Code].....
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Feb 5, 2012
im validating textboxes in my form so it will not allow users to press numbers just letters.the code i'm using is Private Sub Textbox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) _ Handles txtFirstName.KeyPress, txtSurname.KeyPress, txtAddress2.KeyPress, txtCity.KeyPress
[Code]...
what i need help with is, ive created a lable called lblFn next to the FirstName Textbox and would like this to be updated with "Please enter Characters Not digits" if a user enters digits in the textbox, how do i amend the above code to get this working?Basically whatever textbox a user enters wrong data in it updates the corressponding label next to it!
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May 4, 2011
I have created a scrabble game that generates random letters. For the user to type in a word using the random letters they have to type it in a text box.
I want my program to prevent users from typing in letters that are not provided in the text box and to allow them to type in the random letters that are provided.
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Jul 31, 2010
I have a datagrid with 5 columns.2 of these columns will have data entered into them automatically - depending on the entries of 2 textboxes.I can disable these 2 columns ok.How can I have it so that the tab key doea not enter the cells of these 2 disabled columns. ideally I'd like the tab to enter the cells of the abled columns only.
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Jun 29, 2010
I am using a database (access) were i am not using a primary key field. I would like to prevent the user from entering records , if certain fields allready exsists.
I would like to check for 3 of the fields. When these 3 fields has been filled previously with the same data as the new data, i want to return a message.
I am looking at the fields txtWeeknumber.text & txtTopic.text & txtSubOutCome.text
Here are some of my
[Code]....
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May 14, 2012
Is there a way to prevent a user from entering data into a ComboBox, rather then selecting, or can anyone suggest a routine to catch and prevent entries so the user can be made aware the they are not acceptable?
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Mar 6, 2011
I have just about completed a .NET project to write a program to randomly select numbers for a Bingo caller. Over the last month or so Ive learned a lot about .NET but heres something that I consider to be odd and maybe one of you guys can offer an opinion.
One of the features of calling Bingo in a small local club is that callers often use little sayings to accompany certain numbers, I expect youve all heard of (say) All the sixes, clickety click for 66 or 5 and 9 the Brighton line for 59 etc. My little program gives an option to incorporate these with a prompt for the caller that can be edited outside of the program. One of these conventional sayings is used when a number is reversed 12 followed by 21 or 45 followed by 54 for example, when the caller might call (say) 1 and 2, one dozen, number 12 And the other way round 2 and 1, twenty one.
So, I programmed in a bit of code to detect this and to over-ride whatever might otherwise have been the quote with And the other way round and set about testing it. Ive been through literally dozens of full 90 calls watching for the occurrence of a reversed number, spent a few hours doing it, and not once has it occurred which is to say the least, unusual.
So, Im wondering about the Rand Function, could it be that it isnt possible for a reversed number to be selected? Just so you know, I randomly pre-select the order of all 90 numbers, I fill each of the 90 elements of an array with a random number first checking that the number selected hasnt already been stored, if it has, I just get the next random number (and check that too of course), but I cant see how that could prevent reversed numbers being selected, especially in light of the fact that frequently it's not the 'next' number that's used.
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Apr 4, 2011
Title pretty much says it all. Does anyone know a way to to prevent a computer from entering a low/non-processing mode while the program is running? I don't care about monitor modes, screen-savers, hard-drive spindown, etc (in fact, I'd prefer to leave those alone; I like it that it shuts the monitor off after a time period).Basically, I have an industrial program that needs to continually monitor a PCI card it uses for IO; and this activity alone isn't enough to convince Windows not to go into Sleep mode. We normally just shut the power-save features off, but we had an incident where a technician forgot, a customer's machine went to Sleep after the end of the shift, the pumps stopped recirculating, yadda-yadda big mess.
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Mar 7, 2012
I'm entering 123 into a field and getting 231.It's because I'm formating the text as I change it.
Private Sub txtObject_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtObject.TextChanged txtObject.Text = Format(Val(txtObject.Text), Zformat)
End Sub zformat is "0.0"
Initially the field is "0.0". If I highlight it and type "1" I get "1.0" the cursor is now in front of the "1",I then type "2" and get "21.0" and the cursor is in front of the "1",I then type "3" and get "231.0".
It is because the cursor is in the "wrong" position.Is there a simple way to fix this?
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Apr 26, 2009
I tried the following code but it did not work.
Private Sub PasswordDataGridView_UserDeletingRow(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewRowCancelEventArgs) Handles PasswordDataGridView.UserDeletingRow
[Code]....
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Apr 18, 2010
This program is going to submit GET data to our webpage. However, we don't want users accessing the webpage any other way than the program. We can prevent users from sharing the program using HWID authentication, but nothing prevents them from using a packet scanner to get the URL of the webpage. We thought about user-agent authentication, which we will implement, but user-agents can easily be spoofed.
how can we prevent users from accessing the webpage directly, instead of through the program?
Currently we will be implementing:
HWID Authentication to use the program User-Agent Authentication to access the web page Instant IP Blacklisting to anyone accessing the webpage without the proper User-Agent
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Feb 7, 2010
how do I prevent my users for more than one simultaneous login per account. I am using Vb.Net SQL.
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Mar 16, 2011
I have built a vb.net web application. I have tried to make it secure, with all users requiring a password to get in. The only problem is that if anyone can guess (or detect using some kind of hacking tools) the url of the javascript file, they can download it and read it, without even having to log in first.
Is there any way that this can be prevented?
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Oct 10, 2010
How can I allow only letters A-Z (both lowercase and capital) and numbers 0-9 to be entered into a TextBox control? Also spaces are not allowed either.Goldfish64
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May 23, 2009
How do i make it so that you can only type in numbers and letters in a textbox? I want to disable the use of ("*(&$.....etc.) those types of symbols.
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May 19, 2009
I'm looking for some function to put together every possible combination of letters and number to create a string that is 14 characters long. I have found ways to make every possible combination of letters and numbers seperately. However, I've never run across anything to come up with them together. Every string created must contain letters and numbers.I just have no idea where to start on this one.
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Aug 17, 2009
i want to know how to convert numbers to lettres.
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Jun 21, 2010
im a student still learning and im stuck. im writing a program that returns the ip address, splits it in to parts, and now i need it to return a string of letters for other parts to use. EX.
ip address 127.0.0.1 will look like ABG.XXX.XXX.XXA
( i would like to set 0=X so it is easier to pick out the actual
numbers)
I am able to split it and display each part and rewrite it to textboxes without the "." but i dont know where to begin to change the numbers to the letters i need.
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Dec 6, 2010
I'm on VS 2008 I have one form contains many textboxes,when I write in one textbox (UserName) the letters and numbers should distribute to the other texts where each textbox has only one letter or number from the original text to get them ready to be encrypted.
What code I can use in text change event that takes the whole text and throw it in the other textboxes so each textbox has only one value ?
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Dec 7, 2009
My listbox will accept any letter I add, but I can't get it to accept any numbers. I tried a case select for 1-100 and I couldn't get that to work either,
Private Sub btnCount_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCount.Click
'Determine word count and average letters / word in the sentence
[Code].....
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Apr 26, 2009
I want to set the mask for the textbox for only letters and numbers with no spaces like thisthe "*" represents letters and numbers)
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Jul 15, 2011
I have written a program in VB 2010 that dumps documentation info into an Excel file. Basically, the Excel file is a log file that keeps track of revisions for design drawings at an engineering firm.
There are approximately 20 people that have access to this program. However, I've run into issues where multiple users may be using the program and trying to send info to the Excel file at the same time. The Excel file is set to read only. My program opens the file with write access, and dumps the info into the appropriate cells, then closes the file. If one person is in the process of using the program, it causes an error with another persons system if they try to use it at the same time.
In some cases, it causes my program to crash, and it leaves the Excel file open on someones system.
Typically, my program would only have the Excel file open for a couple seconds. So, the issues mentioned above are rare, but they do happen.
I'm looking for ideas to prevent this issue from occuring.
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Nov 15, 2009
I have a textbox which controls the interval of a Timer control. How do I filter out letters? Is it possible to restrict entry to numbers only (like if you enter a letter or a space, nothing happens)? Is there a property of the textbox that can accomplish this?
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Nov 10, 2009
I am creating a simple mathematical game in VB.NET for kids!!the game checks for some simple calculations!!I am having the problem regarding the if else block in the codehere is my code
[code]...
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Jul 17, 2010
How can I generate a random string of 8 numbers and letters?
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Apr 6, 2012
What I am trying to do is create a form with a button and a list box. When clicked the button will generate a list of 3 or 5 characters that have alternate letters and numbers...eg.
q2h
a6j
z4p
d9k
[Code].....
To complicate things a little, each combination needs to be different, ie. randomised but still according to the 'letter,number, letter' formula. There are plenty of examples of randomising strings such as passwords but I cannot understand how to achieve the above.
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May 23, 2009
I want it so that when someone clicks a button it generates a code in the format of XXXXX-XXXXX-XXXXX-XXXXX-XXXXX I want them to be letters and numbers combinations
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Jan 30, 2012
I'm brand spanking new to coding (as well as this forum). And I'm learning Visual Basic 2010 in School. Right now I am working on the following problem: "Use a masked text box to as a user to enter a phone number in a format as follows: (604)323-5819. Make sure you add input mask to the area code and phone number. Both the phone number and the area code are required. Then extract the area code and display it in a text box when a button is clicked." Here is my code, I've got it where I can input the number, and when the button is clicked (things actually appear in the text box!) however instead of getting the area code, I get "als" or alternatively if I put (0,3) I'll get "fals" I don't understand what I'm doing wrong or even where "fals" is coming from. Can someone please explain to me what I'm doing wrong? I've literally been at this since 4pm today and only just (midnight) able to get it to this point and I'm incredibly frustrated as to where these letters are coming from. [code]
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