I'm used to the String.Format method in VB.NET:
Dim mystring = String.Format("Today is {0:d}", Now)
Recently, however, I stumbled upon something like this, which is refreshingly shorter:
Dim mystring = $"Today is {Now}"
However, I wasn't able to find documentation for this new syntax. I would like to know how to use format masks with it, if possible.
That is called "string interpolation" so you can find information by searching for that term. That said, format specifiers work the same way as for String.Format:
Dim mystring = $"Today is {Now:d}"
Related
Im using the FolderBrowserDialog to pick a path.
It will return for ex. this= C:\Mypath1\Mypath2\DOCS
I would like to remove everything but DOCS.
If i use VBA i would use a InStrRev combined with a left. But now in in VB.net and im not sure how to achieve this, im pretty sure there is something better than my old VBA way?
Anyone there that could help, google failed me.
Try this:
IO.Path.GetFileName("C:\Mypath1\Mypath2\DOCS")
Which returns DOCS.
I am not sure what you want to do. But maybe this can help you get the last part of a string
Dim fullPath As String = " C:\Mypath1\Mypath2\DOCS"
Dim Parts As String() = fullPath.Split("\")
Dim lastPart As String = Parts(Parts.Length - 1)
I am writing a program in Visual Basic that writes and reads to and from a Microsoft Access Database. When reading from the database, one of the functions that I am trying to perform is to determine the number of lines in a multi-line string that was written to the database and then subsequently read from the database. Here's what I have tried so far with no luck.
Dim stringLines() As String = databaseReader("multilineString").ToString.Split(CChar("Environment.NewLine"))
Dim stringLinesCount As Integer = stringLines.Length
For some reason, this always results in stringLinesCount being equal to one, regardless of how many lines the string has. In this example, I am using Environment.NewLine, but I have tried \n, \r, vbCr, vbLf, and vbCrLf as well, and they all result in a value of one. Since none of these seem to be working, what can I use instead to determine the number of lines?
Edit:
Dim splitCharacters() As Char = {CChar(vbCrLf), CChar(vbCr), CChar(vbLf), CChar(Environment.NewLine), CChar("\n"), CChar("\r")}
Dim stringLines() As String = databaseReader("multilineString").ToString.Split(splitCharacters)
Dim stringLinesCount As Integer = stringLines.Length
Since Chris Dunaway provided the answer that I view as helpful but posted it as a comment, here's what he said:
VB cannot use C# style escape sequences, so CChar("\n") and CChar("\r") is meaningless in VB. Also, calling CChar("Environment.NewLine") is wrong because you are trying to convert the actual string "Environment.NewLine" to a single character, which obviously won't work. You can just use Environment.Newline directly in the call to String.Split.
If Chris decides to post his comment as an answer, please let me know so that I may remove this.
I have problem to format numbers and convert it to string with leading zeroes when application uses NET framework 2.0 with Visual Basic.
I try:
Dim myNum = 12
Dim myStr as String
Dim myStr = myNum.ToString("0000")
or
Dim myStr = myNum.ToString("D4")
... in order to get wanted string: 0012
Please help to solve this.
You have an old version of Visual Studio, one that doesn't have Option Infer yet. Or it isn't turned on. That makes the myNum identifier a variable of type Object.
So your code tries to call the Object.ToString() method. Which does not have an overload that takes an argument. The compiler now tries to make hay of your code and can only do so by treating ("0000") or ("D4") as an array index expression. Indexing the string that's returned by Object.ToString(). That has pretty funny side effects, to put it mildly. A string like "0000" is not a valid index expression, the compiler generates code to automatically convert it to an Integer. That works for "0000", converted to 0 and the result is a character, just "1"c. Converting "D4" to an integer does not work so well of course, that's a loud Kaboom!
The solution is a very simple one, just name the type of the variable explicitly:
Dim myNum As Integer = 12
Dim myStr = myNum.ToString("D4") '' Fine
VB.NET's support for dynamic typing is pretty in/famous. Meant to help new programmers getting started, it in fact is an advanced technique given the myriad ways it can behave in very unexpected ways.
The universal advice is always the same. Let the compiler help you catch mistakes like this. Put this at the top of your source code file:
Option Strict On
So I've been going around the internet looking for a way to convert regular text(string) into base64 string and found many solutions. I'm trying to use:
Dim byt As Byte() = System.Text.Encoding.UTF8.GetBytes(TextBox1.Text)
TextBox2.Text = convert.ToBase64String(byt)
but it end up with an error saying
'ToBase64String' is not a member of 'System.Windows.Forms.Timer'.
What do I do to fix this? Or if there's a better way to code it please help.
Use System.Convert.ToBase64String(byt). Otherwise the timer is picked up as the innermost matching name.
Not the best name for a timer btw.
If I have a string like input = "AA["
If Right(input, 1) = "[" Then Do stuff
The If statement returns false, even if I try converting things around to chars, etc etc. But if I do this is returns true:
Dim temp As String = Right(input, 1)
If temp = "[" Then Do Stuff
I like knowing little semantics like this, any idea why it comes out this way?
Or don't use Right at all since this is .Net
Dim s As String = "AAAAAAA]"
If s.Substring(s.Length - 1, 1) = "]" Then
Stop
End If
'or
If s(s.Length - 1) = "]" Then
Stop
End If
I've seen weird behavior like that when debugging.
In fact, today I had something simlar
Dim records As Integer
records = If(o.dr Is Nothing, o.ADO.rs.RecordCount, o.ADO.DS.Tables("tbl").Rows.Count)
That should work, using the rs.RecordCount when dr is nothing, otherwise using the Rows.Count. It didn't, records was ending up as zero. Rewrote it as a full if then/else block and it works.
It's never my first thought that the compiler/debugger/ide is messing things up, but you should keep it in the back of your mind for consideration: the programmers that wrote those programs are just as human and fallible as you or me.
It shouldn't. Are you sure you didn't have a typo? The result of RIGHT is a string, and if the input was truly "AA[" the IF will have passed.
I've never had VB act wonky on something like this.
If the code appears in a form, then the .Right property of the form overrides the string manipulation function. You need to specify the parent namespace - e.g. VisualBasic.Right - to ensure that you get the correct method.
I think you may have some kind of strange overload confusion occuring here.
You are specifiing "Right" (which could be calling a local "Right" function).
The function your implying is "Microsoft.VisualBasic.Strings.Right" in most of my code ends up being "Strings.Right" due to the global import.
I would try changing you code to the below and see if it still happens, in order to rule out some overload/scope confusion. (and/or the reduced "Strings.Right")
If Micosoft.VisualBasic.Strings.Right(input, 1) = "[" Then Do stuff