This is related to my last question.Even though Access considers Nulls and zero-length strings (ZLS) separate values, often developers wish to treat them as equivalent for the sake of an If...Then statement or some other stretch of code. One way to accomplish this is to write code like this:
' Not so efficient
If IsNull(varAge) or varAge = "" Then
' do something
[code].....
[Code]...
By my logic, this should only assign .length to index IF the length of strItem is longer than 0. This check is there in case the listbox is empty, or the user has not selected an item. However, everytime I go through this code without an item selected I get:
[Code]...
I have some code that is meant to check the length of the values in the text boxes, and if any of the boxes has no content the length of the string is 0 (or null). Here is the code:
If (Len(Form_MainScreen.Ctl48.Value) Or Len(Form_MainScreen.Ctl49.Value) Or _
Len(Form_MainScreen.Ctl50.Value) Or Len(Form_MainScreen.Ctl51.Value) Or _
[code]....
When one string is blank, the length check becomes "null" and so does the whole statement.But if the length checks are all not null, the if statement becomes a "1" and then procedes to execute the Do X procedure again.
The obvious first thought is:
Public Function CheckStrings(ByVal input As String()) As Boolean
For Each s As String In input
If s.Length > 0 Then Return True
Next
Return False
End Function
I'm sure there is a simpler way than that though. At least simpler in terms of the code if not necessarily the performance.
Here's my final code:
<Extension()> _
Public Function AnyNonZero(ByVal value As String()) As Boolean
If Not value.All(Function(x) String.IsNullOrEmpty(x)) Then Return True
Return False
End Function
I'm generating a list of names from my database, but I need to validate them so they are no longer than 15 characters.
Dim Name As String
Dim txtFirst = "../../Names/first.txt"
Dim txtLast = "../../Names/last.txt"
[Code]....
I need Name to be no longer than 15 characters, and it doesnt matter if the name stays in tact, it just needs to cut off characters from the end of the string until its 15 or less.
I want to create a binary file in vb6 which contains variable length strings and which will be read in VB.NET by using BinaryReader. Since BinaryReader requires the variable length strings should be length-prefixed, I have to write them accordingly.
I tried the following:
type x
y as string
end type
[Code]....
Currently, whenever I pass a string to the db, if that string is empty, then i set that object to NULL by doing the following:
IIf(DescriptionTxt.Text.length > 0, DescriptionTxt.Text, DBNull.Value)
I was thinking about writing a function to reduce the length of this code, and make it more consistent.However, I was wondering, is there already a way of doing this in .NET 3.5?
What I need to do is find a string that can be any value, and is placed between ">" and "</" with a minimun length of 5 and a maximum length of 7 and contains exactly 2 dots.
So if I have a text file like this:
<a href="www.site.com">a site</a>
text<br />
More test<br />
[Code]....
I want it to find only the 5.0.77. And no, the number isn't always between h2 tags, and the number isn't even always the same. The only thing that is static about it is that is is between ">" and "</" and that it is between 5 and 7 characters and contains 2 dots.
I have a Javascript function for my select box, but after I included runat="server" to it, the script debugger highlights on this line below:
' for (i = 0; i < sourceTo.options.length; i++) { ' and says:
SCRIPT5007: Unable to get value of the property 'length': object is null or undefined
I included it because I wanted to loop through it in code behind and perform some other stuffs?
Code:
<select multiple size="8" style="width: 135px" runat="server" id="outletFromBox">
<option value="JP">Jurong Point</option>
<option value="IMM">IMM</option>
[code]...
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, _
[CODE]...
I am trying to call an external C++ function using VB.NET (answers in C# are fine, I can convert back) which returns a list of device names. This comes in the form of a pointer to a null-terminated array of null-terminated char arrays (correct me if I've misunderstood what I'm dealing with) with a function signature:
long GetNames(char*** names)
Most of the answers to similar questions I've found have involved something more like:
long GetNames(char** names, int length)
It appears from what I've read that I need to give it an IntPtr but I'm uncertain as to how this should be initialized, and in my case I don't know the length of the array. At the moment, in the VB module, I have:
<DllImport("MyExternal.dll", CallingConvention:=CallingConvention.Cdecl)> _
Function GetNames(ByRef names as IntPtr) As UInteger
End Function
I've tried calling the function by passing an IntPtr initialized as IntPtr.Zero or using Marshall.AllocHGlobal, but I always get an AccessViolationException.
Any ideas on how I should be calling this function and how I get the return value into a managed string array would be greatly appreciated.
EDIT: I've found a sample function call in native C as follows:
char **tmplist;
GetNames(&tmplist)
I have this simple-minded query:
select a.str_number+' '+a.str_name+' '+a.str_suffix+' '+a.str_apt AS addr from mytable
This query works as long as none of the concatenated values are not NULL. If any is null, the address does not show.
I tried this:
select IsNULL(a.str_number+' '+a.str_name+' '+a.str_suffix+' '+a.str_apt AS addr,'') from table
What I would like to accomplish is to replace NULL with empty space if the value is null but I still get no values.
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
[Code]...
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.
View 2 RepliesSay I have a List(Of Tag) with Tag being an object. One member of Tag, Tag.Description, is a string, and I want to make a comma-separated concatenation of the Description members.Is there an easier way to do this than to read the Description members into a List(Of String) and then use the Join function?
View 2 Repliesthis is not working?
[Code]...
End WhileI am trying to read from the ": " to the end of the line. I keep getting this error: Index and length must refer to a location within the string. Parameter name: length
am getting the above exception while swaping Items in the list(lstRoutePriority).PFB my code
if (lstRoutePriority.SelectedIndex > 0)
{
//Swap the two items
[Code].....
I have an array in my application and I don't know how many values there will be in the array because it gets the data from a webpage. Filling the array with information from the webpage works except for the length, it always returns 999. This is my
dim Array() as string
Array = GBA(source, "<b>", "</b>")
Count = Ubound(Array)
How can I find out the length of my array?
I have an API that loads into memory from a button click. It can then either load an approx 10MB txt file (ASCII comma delimited characters/decimal list as a string) or live timed data from the internet. The idea is to be able to view the data in a text box. From there I can see what I am doing as far as spitting that info into a datagridview or database. The data is completely out of order in the txt file but has various Getinfo Functions / DLL's accessed via button clicks that split the data into its correct format to display in the text box. The problem I am having is not having fixed length strings in VB 2010. I don't know enough to work out if there is a simple work around or something more complicated required. Everything I have tried has left the textbox empty.
VB 2005 code that works:
Option Strict Off - I want to solve with this ON
Option Explicit On - I want to solve with this ON
Imports VB = Microsoft.VisualBasic
Private Sub Command3_Click(ByVal eventSender As System.Object, ByVal eventArgs As
[Code] ....
I am pretty sure that my questions will soon get so annoying you won't answer them, but before it happens.I am using DrawCurve (with density set to default) to draw on my picturebox. I need to know the exact length (well, not *exact* but knowing it is around +/- 1px from exact length would be nice) of the curve drawn.
Is there any function in API I could use to get what I want? If not, could you point me to the algorithm (preferably implemented in any language) that I could use with array of points as an input and length as an output value?
I have a title (in one line) that can have different lengths. I need to print this title on A4 landscape - page ( draw string in print page event), but always it should be located in the middle of the page, regardless of length. If I want to determine the exact location I have to calculate the length of the string in pixels. Or maybe there is a better way to center the string on page? How can I do it?
View 2 RepliesI have a field displaying on a datagrid that the user has asked to be variable length based on the data that is returned. Is there an easy way to determine how many characters are returned for a field and then converting that to a pixel length so that I can change the length of the field in the code.
View 2 Repliesi am trying to import a fixed length text file into an access database (accdb). I already have the table created but it doesn't have to be that way. i am wondering if i know the field lengths, can i a use a SELECT INTO query to get the data into access. or do i need a schema file?
View 1 RepliesI am creating a math related class and one of the problems I have been having was how to create a function to return the fractional part of a double as an integer. I could easily do that if there was a way I could get the length of the digits.
-3.141 should return 3
-0.125 should return 3
-0.5 should return 1
-0.4545 should return 4
I would like to do this without using string manipulation. So far all I have gotten on the web is unanswered questions. I thought of using log, but it doesn't give the desired result when working with numbers < 0
I have a problem with snake game. I never tried to make a game with VB, but now i tried to make snake from this tutorial:So i added food to this snake game, and when i taking food, it increases score, but length cannot be increased and i don't know why. This code is in timer to check if snake head is on the food:
If p(m).X = food.Location.X And p(m).Y = food.Location.Y Then
score += 25
food.Visible = False
[code]....
I am wanting to create 2 tables called Stores and Locations. Locations is a table containing a unique location_code and a location. Stores is a table containing a unique store_code a store name and a variable number of location_code's and a relationship is set up between the 2 tables.
creating the Stores table in particular the location_ code. Can rows in a table have differing numbers of columns? as a particular store type could be in many diferent locations. I feel it should be possible to set up some sort of array of Location_code's in the Stores table.
I need to seperate a name into 2 parts using split the first part being 2 letters "That was easy" but the last part of the name would have an unknown lenght. so how do I get the unknown length? I believe I understand the Join Part here is what I have but it only works when you know the lenght of the name
Project Notes
'Form has two textboxes and one button
'first text box holds a first and last name
' 1-seperate the first and last name into 2 variables
[code]....
Is there a problem with changing the column length in table and using comboboxes that display a partial list of the records from that table.I had a column(Name) that was 18 chars long. I would then display only a subset of those names in a combobox by not listing records where a column called privileges was set to X. This and other uses of combobox worked fine till I increased the column length to 24. The combobox no longer filters on the privileges field though when I select the column priviliges after my selection it will display the value X.
View 1 RepliesNeed to get length of a string minus the line feed chars and came up with this. Is there a better/more efficient way?
Function GetLenMinus_LF(s As String) As Integer
s = s.Replace(ControlChars.Lf, String.Empty)
Return s.Length
End Function
[Code]...
I want to create a ProgressBar with my array length, whithout timer object. When ProgressBar increment, the value in array appears in a label.