When I read a value from text box I want to make sure user has entered a number(int/float/double etc.) not a string. Is there any function to check it? otherwise how do i validate it.
Language : VB.NET
Version : Visual Studio 2005
I am trying to mkae sure that there has been 16 numeric digits entered into the masked textbox. If not show errror message and if so to call the fucnction ValidateLuhn. When calling Validate Luhn i want the program to tell me if the number entered is valid or invalid using the code in the function:
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Vb is not my language of choice , but I have to do this for school and I'm not having a very easy time with VB's documentation.I'm just creating a very simple console application that accepts user input: degrees in Celsius, and converts it into Fahrenheit. I want to make sure that if the user just hits enter without entering the degrees in Celsius, then an if else statement will catch and write to enter Celsius again.Here's what I've tried:
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How to make validation Only Allow letters and Numbers to Input, without any special character in Textbox
View 4 RepliesThe problem i m facing is that i m getting all numbers in this format
1- if it is double then 123.45
2- if it is integer then 123.00 which is wrong
how to format a number wether it is in decimal or integer.if it is decimal then something like 123.56 or if it is integer then 123 not 123.00.Tell me the generalized string function and how to use it..
the task is to have an image move up and down when a number is entered in the text box and the start button pressed. now ive managed to get the image to move up but not to sure how id get it to go back down.the code ive used so far is
Private Sub btnJump_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnJump.Click
While picFrog.Top > 0
picFrog.Top = picFrog.Top - Val(txtSpeed.Text)
[code]....
but it comes up with a error. can someone point me in the right direction of what kind of code i should be using?
I can't round up the decimal number using VB.net
i'm using Cint(12.5) this must be 13 but it is not so i try Round(12.5) but still not roundup what do i do?
Im trying to improve some apps ive written, the first is a console app... Im trying to get it so that i wont get an invalidcastexception if the user inputs a string, when the variable is type "Double"
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I am building a search engine in vb.net which would have to search for a word entered by the user in 40 text files within the project directory. It should return the results as the total number of matches (text files) and the number of times this word is in each file.
View 5 Repliesthe project here is to take the three amounts from three text boxes entered by the user and return a string in a label telling the user if the triangle is either a right triangle, equilateral triangle, or neither after clicking a button. The code I have must use a new Class named Triangle. No matter what is entered in the text boxes, the label always returns "You created a right triangle!"
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I have a Form1 with TextBox1 and Button1.
Here is what I'm trying to do: When Button1 is clicked, I want an Excel file created and saved into a default folder (the user does not choose the folder...code for Button1_Click will choose the folder), and the file name will be the text that the user enters into TextBox1.
I am handling many of the BindingNavigator tasks (MoveFirst, MoveNext, etc.)in code to ensure that I always ask the User to save his changes.
The one area I am have a problem is PositionItem. I would like to sense that the User has changed the Record Number in the BindingNavigatorPositionItem, handle my record Update, and move to the Record Number the User entered I have looked all over and have not found any way to do this.
I have a simple form that works fine with a button click and the code generated by VB for Button1_Click event.But I want to make the user have to double click the button, So I just modified to: [code]This compiles but nothing happens when you double click.What am I not doing to get this to work?The problem is that if you click the button and the form is the focus, then if you hit the enter key it fires the event (when you didnt want to)
View 9 RepliesI want to access (read/write) the user entered text for a document.The document text is housed inside a CONTENTEDITABLE DIV tag within a html document.The html document is loaded into the webbrowser object (webbrowser.navigate(path and filename)).When the html document (bulletin.htm) loads,An error is popped up such as ACCESS DENIED to toolbar.htc and menu.htc And the toolbar and menubar are missing or corrupted.I have tried to generate the code for the document using the code below.
Function ScriptEditorHeader() As String
Dim sBuf As String = Nothing
sBuf = ""
sBuf = sBuf & "<html "
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I'm using a series of nested if/then/else statements to make sure a user enters information into each text box or chooses a radio button. What would i use to say if no text is entered in textbox1, then ... also what would i use to make a sure the user choose one or the other radio button? for example i also have a combo box, i used "If SubjectComboBox.SelectedIndex <> -1" for the if statement.
View 2 RepliesWindows forms Application. VB .NET 4.0 In my application I have a global boolean variable that keeps track of when changes are made and when they are saved called changesSaved. On closing even it checks the value of this variable before closing the window.. I am using textchanged event to automatically change the value of changesSaved to FALSE when text is changed.. Problem: The group box items are being populated dynamically so the user can edit the values or simply just view them. This dynamic population is causing the textchanged event to fire because the program is changing the text value of the box to put the values in that are stored in the database. The textchanged event should not fire unless the user him or herself enters a value or values in the text boxes..
Is there a way to specify the source i guess you could say for the text changed event or another way so that it will only fire when the user inputs information.??? Functions are as follows: The first is called by the load event to place the values in the box... The next one is the one that is being called as a result of the first one and is also the one that is causing the problems.
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Setting a textchanged event to only fire when text is actually entered by user not program
View 1 RepliesIs there any way to tell vb.net (2010) to allow expressions of type Double to be passed to parameters expecting Float, without having to use an explicit CSng() calls, other than by turning off all complaints related to narrowing conversions? Given that a Double->Single conversion will never throw an exception, and given that precision loss does not seem to be a criterion for regarding a conversion as "Narrowing" (Long->Double is considered "Widening" despite the fact that it involves an inexact conversion from an "exact-value" type to an "approximate-value" type; a Double->Single conversion merely goes from an "approximate-value" type to a "somewhat-more-approximate-value" type, so it is in some sense less lossy).I know turning off Option Strict would eliminate squawks about Double->Single conversion, but that is incredibly massively overkill. Is there any way to stifle all complaints about Double->Single, without stifling other possibly-useful squawks?
Edit:If Microsoft isn't going to allow code to be written in the most logical fashion, would it be preferable to litter the code with CSng() every time I call graphics methods, or define NewRectF and NewPointF methods which accept doubles and then use the RectF/PointF overloads for the graphics methods?
I am doing form validation in VB, I validate the text field data by using txtName_LostFocus function, and on wrong input I used txtName.Focus(). It works well for me. But problem is that as for as, user does not input valid text, my EXIT button also does not works.
View 1 RepliesHow can i make the double qoute(") as a string?
dim str as String = """
I want to search for a string entered in a column of a datagridview in a text file.If this string exists in the file then allow the user to enter it otherwise dont allow the user to enter the string.Also,since I am reading data from the database into the datagridview, I have not added columns to the datagridview using edit columns option. How do I do this in vb.net.I tried doing something like this:
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I'm looking for a library for Autocomplete support in text controls which remembers all previous entries of the user and provide auto-complete support for it.For example for "recent files" I use [URL] and it works great. Do you know something like that for this purpose?
UPDATE : This is a .NET Winforms application and I'm using normal Text Control.
How to check if string entered in a text box matches a field in a data table
I have a form with two text boxes for users to enter their Username and Password. When they enter their details and click the 'Login' button I want their details to be
checked against data in a data table to see if they match or not. I am using an 'if...else' statement but can't work out the syntax to use. My code is as follows[code]...Check when string entered in a text box matches field in data table?
I want to make it as an Installer.how can i make it a setup file so that user double click it and the software get installed silently? I used in my program ms-access 2007 database and some other sound files which i linked to my project and some vedio files.Suggest me how can i make all the files as in a single installer or setup.
View 20 RepliesHow to check if string entered in a text box matches a field in a data table.I have a form with two text boxes for users to enter their Username and Password. When they enter their details and click the 'Login' button I want their details to be checked against data in a data table to see if they match or not. I am using an 'if...else' statement but can't work out the syntax to use. My code is as follows:[code]The fields I want to match the textbox strings against in my database table are called 'Username' and 'Password'.
View 2 RepliesI am writing a hangman type game and I am displaying the word to the user in a label as all *'s, but I cannot figure out how to have just one of the *'s changed in the label to the correct letter when the user inputs the correct letter into the text box and clicks the check letter button.Everything else in the program works perfectly, except for this part.[code]When I use the .Replace it changes all of the *'s to the correct selected letter.
View 2 Replieshow would i go about converting a float value to string?
View 9 Repliesvalidation in vb.netemail_id validation,name,mobile number,Telephone number,zip_code,address i want to all code the textbox
View 3 RepliesI am checking for empty string values, but how do i see for the Quantity text box if the user chose only numerical values after the empty string. For example...
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How do you validate input when you are dealing with doubles. I have successfully gotten the message box to pop up when the user enters a number in a text field, but what if I have a text box that requests a number from the user and they enter text? This is the code, the even for btnDisplayFull works fine, but not btnDisplayRqst: [code]
View 2 Replies