I've always use String.IsNullOrEmpty to check for a empty string. It recently come to my attention that a " " count as not a empty string. For example,
Dim test As String = " " If String.IsNullOrEmpty(test) Then MessageBox.Show("Empty String")
[Code]....
It will show "Not Empty String". So how do we check for " " or " " in a string?
I have a DataGridView that has some columns with dates. It binds to an in-memory Datatable which gets loaded from an string array of data passed back from the backend Some of the rows returned have nulls for the date columns. Solution 1: If I define the Date column in the DataTable as "string" I can easily convert those nulls to empty strings and display it in the grid as empty strings (desired results). However, if the user clicks on the date column header to sort by date, it doesn't order the rows as you want. You get a purely string sort order. Not acceptable
As the title says I have a form with many databound textboxes. some of these boxes have data in them and some are empty. I need to add them altogether, so far all of the conversion methods I have tried err out when they run into an empty string, except Val, but then Val won't handle the string with a $ in it. I've tried decimal.parse which handles the $ but not the empty string. So I seem to be in circle that I can't get out of.
I am developing an app which has a TabControl and Several TabPages. However when I switch the taps to be dislayed on the side I am left with a large amount of empty space. I am unable to move the TabPage to remove the empty space.
I got a text box and a panel.The textbox is at the bottom, and the panel is above it, making a open white space above it.The thing I want, is that when i type "run" into the textbox.The empty space should start displaying messages of its actions.Just like in command prompt.If you open a cmd window. (make it small) then type in "ipconfig" (as an example), the text that shows up, makes the scroll bar, follow it down.
I am using 2010 express, and when I try to use it to open a program that I had made with 2008, it will open and it will allow me to debug the program, but neither the designer nor the code will show. It is just an empty space in the middle of the screen.
This must've have been asked before but I couldn't locate it. In a mixed code project (VB and C#) we were debugging some old Visual Basic code where a statement as follows could be found:
If Request.Params("xxx") <> "" Then 'do something
I considered this a bug as Request.Params could be null, in which case the statement would've become false which wasn't the idea. So I thought. I just found out, -- probably for the tenth time and I will keep forgetting -- that the following two statements are not equal, while Nothing in VB should be equal to null in C# (thought I):
if(String.Empty == null) // always false If String.Empty = Nothing Then ' always true
Should I dismiss this as a typical Microsoft backward compatibility effort, or should I consider this a huge error in the VB.NET compiler? Does anybody know the Microsoftean opinion on this oddity?
I have a VB.Net project. The form has a panel and few buttons inside panel... The problem is that the background image of the panel is only visible behind buttons....but not in empty space....The app is running fine on Windows 7 but the problem comes on XP....I have tried "Enable XP Visual Styles" but no luck....When i dock a button to fill all empty space then the background image is visible....but if i remove the button ... background image is not visible....
I want to get a string between 2 strings using Regex.The the string I have is "<b>hello</b>", now I want to get the string between <b> and </b>. I guess its something like Regex(String, "<b>(.+)</b>" but I'm not sure how to do it. I know there is this function called GetBetween but I guess this is a better way.
Speed is critical in my application. As of now, I'm using an ArrayList to store a list of Strings and I use BinarySearch functionality of ArrayLists to search for an item. Would I be able to do this faster using String Collection and a for loop?
How can I change the following code to write to the database null instead of empty strings?
Public Sub SetChangeRequest(ByVal referenceLeaseID As Integer, _ ByVal referenceCustomerID As Integer, _ Optional ByVal custUnitNum As Object = Nothing, _
I have a problem in that I have five text boxes pertaining to a customer/client, where there is a txtbox for each: Name; Address; City: State; Zipcode. Of course all the txtboxes are "" at initialization. I also have 2 combo boxes and a 2D array for prices which I have finally been able to understand the array logic. I have also been able to do my necessary calculations for.
My problem. The customer information is first to be validated as all being strings and not empty. The combo boxes I was able to get to tie to my 2 dimentional array and get good output and calculations for a finished product. I am just having problems with the error messages. Also I don't want summary totals unless the data is valid. In other words, the user must enter a complete address and make decisions about the two combo boxes, both of which are needed to use the price array. I will change the comboBoxes to represent dress sizes,"S" "M" "L" and "XL" and the other combobox to describe colorRedSatin or colorBlackBroadcloth with a two dollar difference in price between them. 'That would be similar enough to the problem I need to solve.
Basically I do not want any numbers to appear for price of the dress or addons to the dress unless all validation is complete. I do understand how the radio objects work for discounts and check boxes for accumulating accessories. The program should not give any totals untill the user has input all customer information and made decisions about input from combo boxes and selected calculate from menu. Right now it calculates and puts zeros in when choices are not made from the combo boxes by the user. It will include correct amounts for radio buttons and checkboxes if anything is entered. I need error messages for customer inputs and combo box inputs (if not selected from list of option in drop down for choices) (basically if nothing was put in a text box, the text box is empty. Of course the problem is the user must enter something in all 5 textboxes and not get multiple error messages in rapid succession to fix. We can't always count on our users putting in good data.. When I tried a Do While False with ORs I was getting endless looping. I could not get it to work because it will never execute because the control never passes back to the user.
I don't want to list a series of If/Thens becauser the user will see about 7 messages, where he/she only needs to be fed one at the time. I hope someone can give me some direction. I just need guidance on how to validate the text boxes and combo boxes. The code is analyzed with a "Calculate" on the menustrip. I would like for the calculation not to calculate and put outputs into the summery text boxes unless all textboxes are filled and combo boxes are valid for all the customer information and combo box choices for my two combo boxes describing what is needed for the order to calculate. There are also the radiobuttons and checkboxes, DIMs, Const, Variables, but not having problems with that part I have my indexing problems on the combo boxes worked out also, so I am not concerned about those now except for getting the error messages when I should. I hope that I have described my issues fully. I am using visual studio 8 with Windows 7
I have a list of strings. For each string in that list, I want to prepend another string. I wrote a method to do it, but I was wondering if there was something already in .NET I could use to do this. It seems like something that could be built in, but I was not able to find anything.
Here is the method I wrote:
Private Function PrependToAllInList(ByRef inputList As List(Of String), ByRef prependString As String) As List(Of String) Dim returnList As List(Of String) = New List(Of String) For Each inputString As String In inputList returnList.Add(String.Format("{0}{1}", prependString, inputString))
[code].....
It works, but I would rather use built in functions whenever possible.
How would i get a certain text inside a textbox to equal that text space to space or null to space?
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click If Textbox1.Text.StartsWith(Textbox2.Text + " ") And Not String.IsNullOrEmpty(Textbox2.Text) Then Textbox1.Text = Textbox1.Text.Remove(0, Textbox2.TextLength) Textbox3.AppendText("a") End If
Btw: after i finish this step my project will be finished!
i have a requirement that my <xsd:string> should allow space.it should not validate the space. but naturally it will not allow space. but i need it should allow space.
I would like to get the width of some text drawn by GDI+ in an Integer so that I can adjust the position of a cursor.
I used:
"lCursor = g.MeasureString(vInputText, Font)"
In which 'lCursor' is the offset for the original location of the cursor. But apparently the output of MeasureString is not integer and can't even parse it to integer.
I got the following code to capture information for files on a specified drive, I ran the script againts a 600 GB hard drive on one of our servers and after a while I get the error [code]How can I avoid getting this error? The server drives are quite a bit <????> and I would imagine that the CSV file would be at least 40 MB.I commented out some lines in the code, using double ticks ('') so you can see where.
How do I add a space between every character in a string of text?For example:Change abcdefg" To "a b c d e f g"I have two text boxes on my form, one for input, the other for output of the re-formatted string.
In the following examples, underscores represent the spaces:
Quote:
_x-xx-xxxx_x.xx.xx_xx
I need to remove just the first space. Now, i tried just replacing the space with nothing, like so:
VB.NET
If s.Contains(" ") Thens = s.Replace(" ", "")End If
But, that removes every space. I also tried .StartsWith, but it still removed every space. I didn't actually expect that to work, but if I hadn't tried it, I wouldn't have actually know.
I want to Replace a string with space here string is comming from DB, here string looks like as followes (This is my first name : "rama" and my second name : "krishna") so now i want to replace the above String as ( This is my first name : rama and my second name : krishna ) So i want to replace " this with Space..
I was trying to call a method using Reflection on a method that has a STRING parameter.However a STRING does not have a parameterless constructor.So instead of something like.>>
Option Strict On Option Explicit On Option Infer Off Public Class Form1
i have a string array that i want to output to a text file. the array size is 10000. i fill the array starting from 0 with some strings. at the end, i only want to show the array from index 256 to the last array that is not empty (for eg. if the array is filled with data from 0 to 2000, i only want the text file to show the data from 256 to 2000 and ignore the remaining strings). Is there any function to do this?t i use is shown below
Dim myArray(10000) as string Dim strArray As New System.IO.StreamWriter("c:List.txt") strArray.WriteLine("{0,10}{1,30}", "Index", "Symbol")
Is there an easy way to find a certain string within a string and then return the strings that you find as an array?I have written this:
Public Function FindStrings(ByVal strSourceString As String, ByVal strStartString As String, ByVal strEndString As String) As String() Dim StringStartposition As Integer Dim StringEndPosition As Integer Dim Currentposition As Integer = 1
I have this string called time. It's value is in this format: HH:MM:SS The numbers change, but the format stays the same. I want to separtate the code into 3 strings Hour, Minutes, Seconds.