Just wondering what the preferred/practised data type conversion technique is?
For example I recently enabled option strict, which in turn found quite a few errors in relation to data types, vb.net prompted me to use CType, which is fine.
However, I have seen other functions for data type conversion, such as .tostring, CInt , Convert, integer.parse and also Ctype.
Why would you use Ctype over the others?
I know its a pretty primitive question , but why do so many conversion methods exist?
i have a Problem with UNION for LINQ to SQL I have my LINQ query
Dim dc As New ContainerDB.DataClassesDataContext() Dim test = (From container In dc.GetTable(Of tbl_container)() Where container.pkContainerID = iPkContainerID).Union( _ From containerHist In dc.GetTable(Of tbl_containerHIST)() Where containerHist.pkContainerID = iPkContainerID)
VB.Net just showing its true colors again? When I turn Option Strict On, I am still able to do implicit narrowing conversions in a for each loop.For example, this code actually compiles;
Private Sub foobar() Dim foo() As foo = {New foo} For Each bar As bar In foo[code].....
From my understanding of Option Strict, this should not work.See here "Restricts implicit data type conversions to only widening conversions".My code above is a narrowing conversion, and so should be illegal.It will fail at runtime with an InvalidCastException. C# does the same thing. Below is another implicit narrowing conversion.
With Option Strict On, I am getting an error with the above code, which is part of a procedure to add a new record in an 2003 access database table named "Jobdata". The items in Combobox3 is populated by another table in the same database, which has a Status field and a Key field. What I'm trying to do is to insert in the Status field in Jobdata table the correspoding integer value in Key to which ever status is selected from the combobox.
I am a novice programmer to VB 2008 and I am trying to develop the following code for a game. When I build the following code, an error message appears: Option Strict On disallows implicit conversion from integer to string. Another error message appears: Name FuchsiaTurnScoreLabel is not declared.
Option Strict On Public Class PlayForm 'Declare integer and decimal variables for calculations [Code] .....
Option strict on disallows implicit conversion from 'Integer?' to 'Integer', 'Integer' to 'String'
Here's my code which is just a stub. I am working off of some example code and applying it to my own project:
<System.ComponentModel.DataObjectMethodAttribute _ (System.ComponentModel.DataObjectMethodType.Select, False)> _ Public Function GetTrackActivitiesByParams(ByVal ActivityKey As Nullable(Of
I decided to turn on "Option Strict" to see all my implicit conversions that were going on WOW there were alot.I am making changes when I discoverd the following problem:With Option Strict Off , everything works great
Option Strict Off Dim glahh As Integer = (Me.subj_gla_txt.Text * 120%) / 100 Dim glah As Integer = (Me.subj_gla_txt.Text * 115%) / 100 Dim glal As Integer = (Me.subj_gla_txt.Text * 85%) / 100
[code]....
I get run time error can not convert string "" to Double at the last line That error I thought would indicate that Me.List2_glatxt.Text is empty? I dont see how it could be since that line in the code above as integer works?
[code] I get the error message of "Option Strict disallows implicit conversion from Long to UInteger." [code] I dimensioned each variable as a UInteger and not a Long, the values for both X & Y are well below the maximum values of a UInteger as far as I can tell (Data Types Summary). [code]
I have to take over a project written in vb.net, which contains more than 400k lines of code written in option strict off mode. I want to build it under option strict on first before I do anything else -- which maybe converting it into C#. I found there's thousands of lines of code raises compilation error, mostly are about implicit type casts. Is there any tool would help to make it compile under option strict on mode if I don't want to correct every single line manually? Because it's really painful to add CStr/CInt invocation into every line of Code myself.
Consider the requirement to always declare Option Strict On. We'll always need to declare variables with the As keyword. What would be the type of an anonymous type?Example : Dim product As ... = New With { Key .Name = "paperclips", .Price = 1.29 }
I have inherited a VB.NET application that I need to compile so I can run dorkumentation on it. I first received "Option Strict On disallows implicit conversion from x to y" errors, so I turned off the Option Strict option in the Project file.
So why do I still fail with the same error message?
I really like the coding speed that vb.net provides, but I don't like the possibility to forget to declare variable types, return types of functions, etc. and that is why in each class I use[code]..
Is there a way to define those two options on the project/solution level?
what does these two code means in vb.net: Option Explicit on Option strict on i think option explicit means the compiler is not going to do any kind of conversion and i need to do all of them by the code;also it becomes case sensitive i.e;
I am tightening up my coding with the Option Strict set to ON. It has now produced alot of errors. An example of this is:
If AllocatedDGV.Rows(i).Cells("RoomNumber").Value = RoomsAvailableDGV.Rows(j).Cells("RoomName").Value Then
It gives me the following error: Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity.
I need to write an interface to get data to/from our data files.
We have a low level class that holds field values for each record read from the files.
This just holds two values, the value read from the file (DBValue) and the updated value that may need to be written back to the file (CurrentValue).
These values may be any of the standard value types (integer, date etc) or a string.
Either value (DBValue or CurrentValue) may be null if not defined.
I have written the class to manage this data which works fine while option strict is NOT on.
But we have an office policy of having option strict on all the time.
When I put option strict on, my object value comparisons fail with the error: "Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity."
Question, how should I change the following code to handle option strict on ...
1. I have read that keeping Option strict on and Option infer off is good practice and will insure your code is tight and properly written. I would like input regarding this, pro's and con's from those who are in the know.
2. Having said that, I have set Option strict on and Option infer off in an existing program I wrote (that was working perfectly mind you) with them off and on respectively. I went through and cleaned up all the errors on the 'need AS' and casting of variables, but one is leaving me a bit put out.[code]
I have also read where using My.Computer.System.Directory.GetFiles() instead of System.IO.Directory.GetFiles() is probably not a good thing, but when I change to this I get no error, but also no dataI am thinking I should stay with the strict on and infer off but am really slogging through getting this code correct.Running Win7 on Dual Quad Core XEON Intel Extreme with 8Gb RAM.
When I have Option Strict ON in my project, the IDE tells me that "Option Strict On disallows implicit conversions from 'System.Data.ParameterDirection' to 'String'." How can this be, since I'm using their built-in enumeration for the SqlParameter direction.
I am pulling data from a local MSSQL database using a stored procedure, then send the data to a web service. Every part of the component works well except for a pesky problem will a DBNull being returned from the DataRow field, when I know that the field is not null and has valid data. The database and associated INSERT statements that add to this field are designed to not allow NULL entries. When I debug break the program on or right before the line that throws the error I see that the field has valid data for the current row.If I add a null check to the code (as below) the operation continues as normal:
Dim dataResultsTable = Me.myViewTableAdapter.GetData(int) For Each myDataRow In dataResultsTable.Rows If worker.CancellationPending Then
[code]....
Why is the read operation returning DBNull instead of the data in the database?
EDIT: Just to be clear, the operation does return the proper data, but the data is not being saved into the variable.
what do you thinkg about comment below? original article url is also suggested to read.I didnt get why my code will be faster if i use it on. anyone has good knowledge about it?
Although Visual Basic .NET allows you to perform implicit type conversions and late binding, you should avoid these practices. Implicit type conversions and late binding may lead to severe performance problems, runtime errors, code that is difficult to read and maintain,and sub-standard programming practices.Many VB.NET professional programmers believe that leaving OPTION STRICT OFF by default was perhaps Microsoft's worst decision in the VB.NET implementation. Use OPTION STRICT ON.
I have an old programme that was written with 'option strict off' I have been steadily working through it mainly sorting out casting issues but have come up against some that I dont understand.for instance I have a checkbox called tickbox
dim Tickbox as new checkbox
later in the code
dim blah as boolean = Me.Tickbox.CheckState
but option strict insists i cast it as a boolean
dim blah as boolean = CBool(Me.Tickbox.CheckState)
Do you use 'strict off' option, 'explicit off'? Or may be 'strict custom' and some other options like 'Implicit type. Object assumed', 'Late binding', 'Implicit conversion'?
