Prevent Non-numeric Input In Program?

Nov 5, 2010

I'm working on a program that requires the user to input an integer. How do I prevent the user from entering a non-numeric value? I tried using the IsNumeric() function but I get an error before I can use it. I get the error at the console.read, before I can call the IsNumeric() function. [code]...

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Get The App To Accept Numeric And Operator Input While Ignoring All The Alpha Input?

May 10, 2010

I am writing a calculator app in VB Express 2008. I'm trying to get the app to accept numeric and operator input while ignoring all the alpha input. In other words taking input from the numeric keypad and the top of the keyboard and ignoring all the letters.

Here's the block of code I have so far:

Private Sub TextBox1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
If (e.KeyCode >= Keys.D0 OrElse e.KeyCode >= Keys.NumPad0) And (e.KeyCode <= Keys.D9 OrElse e.KeyCode <= Keys.NumPad9) Then
Select Case e.KeyCode

[code]....

I can't get vb to recognize the above code it seems to skip right over it. BTW, is 'Keys.Crsel' the same as the caret '^' symbol?

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Validating Numeric Input?

Mar 11, 2010

can anyone look at this and see why it doesn't work? When I test and enter a numeric value in the text box it still gives the error I have placed in the code, same if I put in a letter etc.

Private Sub valueDouble(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtTestscore1.TextChanged, txtTestscore2.TextChanged, txtTestscore3.TextChanged

[code].....

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Filter Textbox Input To Numeric Only?

Jun 2, 2009

How do I suppress all data except numeric?

This is not working on KeyDown():

If e.KeyData < Keys.D0 Or e.KeyData > Keys.D9 Then
e.Handled = True
End If

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How To Make Sure That User Input Is Numeric

Sep 29, 2010

I am writing a small program here and this i=code is straight out a book and it doesn't seem to work. Its supposed to ensure that the users input is numeric and not contain letters.

Module Module1
Sub Main()
Dim user_Input As Single
Dim H As Single
Do
Console.Write("Enter you'r Height in Meters: ")
user_Input = Console.ReadLine
Loop Until IsNumeric(user_Input)
H = CSng(user_Input)
Console.WriteLine("You are {0} meters tall", H)
End Sub
End Module

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Input A Negative Or Non Numeric Data?

May 10, 2010

i have finished my code and the program works but i need setup a few error messages incase a user inputs invalid data (non numeric, and negative numbers)i keep getting both errors at the same time when i input a negative or non numeric data. My program allows a user to calculate cell phone bill

[Code]...

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Making All Textbox Input Numeric Only

Jun 9, 2011

I have a function in my textbox1 with the got focus event. I have a 40 textbox in my goupbox1.[code]I want that when the textbox1 gotFocus, all my textbox in groupbox1 under the for loop event will declare that only numbers are allowed to be entered in all the textbox. I manage to work with it but only in a single textbox. Here is my code for it.[code]Is there a way or would it be posibble to put this code # 2 into the code # 1? So that I don't have to declare 40 TEXTBOX which is not good.

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VS 2008 Numeric Input Format?

Aug 25, 2009

Is it possible that a user input to a textbox like '12500', but vb shows it

'12,500' at the time of input.

But at the saving time vb should to read the '12,500' as '12500'.

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Check Invalid Input - Whether The Text Box Is Numeric Or Not?

Jul 18, 2012

How can i check whether the text box is numeric or not? Because i want to do validation. but i tried many style still cannot work.

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Creating Text Input Based On Numeric Value

Mar 24, 2010

I currently have a subroutine that generates a file with specific parameters, and it relies on user input in 2 fields. Now I also have a numericupdown control. What I'm looking for is a way that if Numericupdown.Value = 3 then it will generate 6 textboxes and once the parameters are filled out completely it will generate subroutine times(numericupdown.value) and output it to a single file.

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Validate Input Boxes For Numeric Value And Range Value

Jan 14, 2012

I'm trying to validate input boxes for numeric value and range value. If I validate for either numeric value OR range value there is no error (for example, comment out one of the validation statements), but if both statements are present and I enter "a" I get an error "Conversion from string "a" to type 'Double' is not valid." Can anyone tell me what I'm doing wrong?

[Code]...

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Validate Numeric Input With Text Boxes?

Apr 29, 2010

i am use vb 2003 windows app with access 2003 database i want this code to check for numeric input only in the last text box CompanyProdPriceTxBx.Text

this is my

Private Sub SaveCompanyProdbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SaveCompanyProdbtn.Click
Dim rep As Integer
If CompanyProdNameTxBx.Text = "" Then
rep = MsgBox("Please Input Product Name", MsgBoxStyle.Critical)

[code]....

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Page Calculator - Converting Input To Numeric Variables

May 16, 2009

Description of Program/Events. I would like to come up with a number generator that takes the Total number (for this example I'll say 20), divides it by 2, and does alternating additions so the end result will generate a list like this:
1, 11, 2, 12, 3, 13, 4, 14, 5, 15, 6, 16, 7, 17, 8, 18, 9, 19, 10, 20.

I can understand the arithmetic, just can't work out how to express this in code. The end result would be save in a .Txt file (I have added a SaveFileDialog1 control, but figure I need to get the result before I work on the export).
Dim StartValue As Integer
Dim EndValue As Integer
Dim TotalValue As Integer
' Convert input to numeric variables.
StartValue = Val(StartNumTextBox.Text)
[Code] .....

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VS 2008 Validates The Numeric And Decimal Input For A Textbox

Jun 3, 2010

I found a function that validates the numberic and decimal input for a textbox and works exactly like I want. But it does not let me limit how many numbers after the decimal. how to do this in the same function?

[Code]...

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Input Validation To Prevent Negative Values?

Apr 14, 2009

I am trying to create an input validation for my program to prevent the user from entering negative values. I've been using:
If (decLabor < 0) Or (decPartss < 0) Then
MessageBox.Show("Input prices for parts and labor must be positive")

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Prevent A Textbox From Receiving User Input?

May 5, 2010

Preferably without turning the "Enabled" property to false, because I still need to output text from it.

I made a custom control in which there is a textbox but I want it used only as an output control, for showing text and stuff. Problem is that as soon as my form opens up the focus is turned to the textbox and I cannot catch my keyboard events on the form anymore(since the other controls are pictureboxes). I need a way to make this box "unclickable" or any way in which it is impossible to attribute the focus.[url]...

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Is There A Numeric Text Box Not An Up-down Box A SIMPLE Numeric Box Into Which The User Can Place A Number

Apr 6, 2012

Is there a numeric text box, not an up-down box, a SIMPLE numeric box into which the user can place a number, 5 boxes actually, then on command have the five boxes added and the sum displayed?

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How To Prevent Program Being Started Twice

Apr 8, 2010

I have a small problem with my application. When the system starts up, the program starts with it, but runs hidden (registry key with paremeter). The program also has a GUI.I want it so that when the user clicks the desktop icon, it does not start a second instance of the executable, but instead reveals the currently running background process. Is that possible?i.e. when the application is started with the "-startup" paremeter, it loads a hidden form2, and closes form1. When the desktop icon is clicked, it loads form1, while form2 remains hidden.

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How To Prevent Program Running Twice

Oct 24, 2011

i got 2 program here...exe and B.exe.. B.exe is external program.. how can i run my program just once at same time? all start from .exe.. if .exe running twice, a messagebox appear ".exe already running".. if .exe detect B.exe was running, a messeagebox appear "B.exe already running".. i'm using Visual Basic.NET..

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Prevent Another Program From Downloading?

Aug 8, 2011

i want to be able to prevent an application from downloading. For example Utorrent. I have seen applications that can do this but never been able to integrate it in my own application. Also i have tried blocking the application's allowed ports in my windows firewall

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Prevent From Closing A Program

Jul 6, 2010

How can i prevent from closing a program even with the task maneger?

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Prevent Program From Loading Twice?

Jan 20, 2010

I have a VB.NET program. In proerties/Application I checked Make a Single Instance Application. But it still allows someone from opening the program while already opened. How can I prevent this?

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Prevent Program Opening More Than Once?

Apr 15, 2009

I'm using Visual Basic 2008 Express Edition. When I have my personal program open, I don't want another instance of it to open. I would like it to detect if the program is already open and if it is, it won't open another.

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Prevent People From Sharing Program?

Apr 16, 2009

I want to make it so my VB program can be registered to be used with only one computer & possibly be registered online.

(Yes i searched the site but i saw no useful program registering guides that i uderstood and worked with the newest version of Visual Basic .NET)

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VS 2010 Prevent Program Freeze?

Apr 28, 2011

my program freezes untill the loading has finished.Is this normal? And if it is then how can I prevent my program from not allowing me to go back to the other form untill the loading has completed?I'm using this url as a start up page for my custom browser;so can I prevent my program from freezing or not ?It looks as if my custom browser form keeps demanding focu

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Create A Nullable Optional Numeric (integer/double) Parameter In Program?

Jan 18, 2010

How can I create a nullable numeric optional parameter in VB.NET?

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Input Any Words In Textbox - The Program Will Reply By Sound Of What Input In The Textbox

Jul 7, 2009

i use visual basic 6 i already try making a button to play sounds. by clicking the button and the sound will out. so that i want to know were could i start, when you input words in textbox the program will speak what you have type in the textbox.
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Either End The Program Or Start The Program Over In A Visual Basic Console Application - Based Upon User Input?

Apr 8, 2012

I have a procedure at the end of my console application that ask the user to either hit enter to end the program, or type s to perform another search. The issue I'm having is no matter what the user types in the program end. What I would like to happen is if the user types s, then the program starts over and lets the user perform another search. The program is procedural and I need to find a way to start back off at the top of the program which ask the user to type a name to search.

[Code]....

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How To Prevent User From Resizing Program During Run-time

Mar 22, 2009

How do I prevent the user from resizing my program during run-time? I know how to disable the max and min buttons at the top, but I can still click the edge and drag it to resize my program. I want to be able to disable this feature so my program stays the same size the whole time.

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Mscomctl.ocx File Which Prevent Me From Opening A Program?

Jun 26, 2009

I've been trying to open a program called 'DET 3' which is designed by the Honduran government and helps us pay taxes for the government. I've been getting this error message when I try to open the program "Component 'Mscomctl.ocx' or one of its dependencies not correctly registered: a file is missing or invalid" I need this program to work so I can pay my taxes before July 10th.

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