Convert A Type To String That Can Be Compiled In Program?
Mar 6, 2010I need a function that will convert a type to a string, for example[code]...
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Convert String Value To Type And Pass As Type Parameter.
Nov 19, 2010i am getting all filenames from a directory.parsing out the directory names & the .vb extension then converting those filesnames to classes.Every file in the LPCriteria direcotry is its own class with a "Evaluate" function.[code]
View 1 RepliesConvert From Type 'ListItem' To Type 'String'?
Aug 28, 2009In a VS 2008 ASP.net 3.5 aspx.vb file, Response.Write(DDL.SelectedItem) worked very well.But "Dim filenameDDL As String = DDL.SelectedItem.Text" did not. Then I tried the following codes and found the problem -- Conversion from type 'ListItem' to type 'String' is not valid.
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C# - Solve This Error "Cannot Convert Lambda Expression To Type 'string' Because It Is Not A Delegate Type"
Jun 12, 2010. I get this error: "Cannot convert lambda expression to type 'string' because it is not a delegate type" - keyword select become underlined in blue
[Code]...
Above code should displays drop list of employees first name and last name in a combo box
How To Convert String To Type Uri (simple)
Apr 23, 2012What is the quickest way to convert a string value of a URL to type URI? VB.NET please..
View 2 RepliesConvert A String To Generic Type T When T Is A Valuetype?
May 1, 2012fast way in VB to go from a string to a generic type T constrained to a valuetype (Of T as Structure), when I know that T will always be some number type?This is too slow for my taste:
Return DirectCast(Convert.ChangeType(myStr, GetType(T)), T)
But it seems to be the only sane method of getting from a String --> T. I've tried using Reflector to see how Convert.ChangeType works, and while I can convert from the String to a given number type via a hacked-up version of that code, I have no idea how to jam that type back into T so it can be returned.
I'll add that part of the speed penalty I'm seeing (in a timing loop) is because the return value is getting assigned to a Nullable(Of T) value. If I strongly-type my class for a specific number type (i.e., UInt16), then I can vastly increase the performance, but then the class would need to be duplicated for each numeric type that I use.
It'd almost be nice if there was converter to/from T while working on it in a generic method/class. Maybe there is and I'm oblivious to its existence?
Conclusion:Testing the three provided implementations below and my original DirectCast/ChangeType form, @peenut's approach of using a prepared delegate to fetch the Parse method from a basic type works. No error checking is done, however, so implementors need to remember to only use this with valuetypes that have a Parse method available. Or extend the below to do error checking.
All runs were done on a 32bit system running Windows Server 2003 R2 with 4GB of RAM. Each "run" is 1,000,000 executions (ops) of the method to be tested, timed with StopWatch and reported back in milliseconds.
Original DirectCast(Convert.ChangeType(myStr, GetType(T)), T):
1000000 ops: 597ms
Average of 1000000 ops over 10 runs: 472ms
Average of 1000000 ops over 10 runs: 458ms
[code]....
Comparatively, peenut's approach is almost 200ms faster when executed 1,000,000 times in a tight loop, so his approach wins out.
How To Convert Boolean Type Into On / Off Using String.Format
Jan 3, 2011Is there are any way to convert boolean type into "ON"/"OFF" using string formatter
Like:
Dim inpValue as Boolean
Dim outValue = String.Format("0:ON;OFF", inpValue)
' should show OFF as output
I cannot use code or IFormatProvider
.net - Faster Way To Convert From A String To Generic Type T When T Is A Valuetype?
Jan 6, 2011Does anyone know of a fast way in VB to go from a string to a generic type T constrained to a valuetype (Of T as Structure), when I know that T will always be some number type?This is too slow for my taste:
Return DirectCast(Convert.ChangeType(myStr, GetType(T)), T)
But it seems to be the only sane method of getting from a String --> T. I've tried using Reflector to see how Convert.ChangeType works, and while I can convert from the String to a given number type via a hacked-up version of that code, I have no idea how to jam that type back into T so it can be returned.
I'll add that part of the speed penalty I'm seeing (in a timing loop) is because the return value is getting assigned to a Nullable(Of T) value. If I strongly-type my class for a specific number type (i.e., UInt16), then I can vastly increase the performance, but then the class would need to be duplicated for each numeric type that I use.
It'd almost be nice if there was converter to/from T while working on it in a generic method/class. Maybe there is and I'm oblivious to its existence?
Conclusion:Testing the three provided implementations below and my original DirectCast/ChangeType form, @peenut's approach of using a prepared delegate to fetch the Parse method from a basic type works. No error checking is done, however, so implementors need to remember to only use this with valuetypes that have a Parse method available. Or extend the below to do error checking.
All runs were done on a 32bit system running Windows Server 2003 R2 with 4GB of RAM. Each "run" is 1,000,000 executions (ops) of the method to be tested, timed with StopWatch and reported back in milliseconds.
Original DirectCast(Convert.ChangeType(myStr, GetType(T)), T):
1000000 ops: 597ms
Average of 1000000 ops over 10 runs: 472ms
Average of 1000000 ops over 10 runs: 458ms
[code]....
Using System.Reflection and calling InvokeMethod to get at the Parse method:
1000000 ops: 12213ms
Average of 1000000 ops over 10 runs: 11468ms
Average of 1000000 ops over 10 runs: 11509ms
Average of 1000000 ops over 10 runs: 11524ms
[code]....
Konrad's approach to generate IL code to access the Parse method and store the call into a delegate:
1000000 ops: 352ms
Average of 1000000 ops over 10 runs: 316ms
Average of 1000000 ops over 10 runs: 315ms
[code]....
peenut's approach of using a delegate to access the Parse method directly:
1000000 ops: 272ms
Average of 1000000 ops over 10 runs: 272ms
Average of 1000000 ops over 10 runs: 275ms
[code]....
Comparatively, peenut's approach is almost 200ms faster when executed 1,000,000 times in a tight loop, so his approach wins out. Although, Konrad's wasn't far behind and is itself a fascinating study of things like ILGenerator.
VS 2008 Convert Access Database Null Values To String Type?
Jun 7, 2011i am working in windows appl vb.net 08. And i am working in Access DataBase.I have one Table Called "Person" . In this "Person" Table one Column Name Called "OtherName". In this Column binded in one of the Combobox in a Form.But the Problem is "OtherName" Column having the Null Values.Before i bind this Column to Combobox i want to convert this NULL Values to String. Why i need the values in STRING means , In my code i using this Combobox as a filter in SQL Query.If i didn`t change the Null Value to STRING , The Combobox SelectedText or SelectedValue is Showing Nothing. So i am not able to get the Record.
Whn i write a Sql Query to Combobox and apply filter in WHERE statement like Combobox.Selectedtext or Combobox.SelectedValue In "Selected Change Committed Event" then i should get the record in the Output right but unfortunatly i am not getting the Record. The Record Count in DebugPrint showing 0.
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Value Of Type 'System.Func(Of String, String)' Cannot Be Converted To 'System.Convert
Feb 17, 2011Value of type 'System.Func(Of String, String)' cannot be converted to 'System.Converter(Of String, String)
Why? They are both effectively a function pointer (or delegate?) to a function that accept a string and return a string.
Convert A String To Decimal In Program?
May 19, 2011What will be the easiest way to convert a string to decimal?[code]...
View 4 RepliesRun A Compiled Program?
Feb 25, 2009I am not a programmer or anything like that but I have managed to create a little program.The program is for work. It is VERY simple - it adds a few figures the user inputs and then generates a text output so the user can copy and paste it to a customers diary notes on the customers account.Here's the problem: It works on the managers computer but not on the consultants computers who will be using it! The reason it doesn't work is because the normal consultants computers don't have .NET installed :( The solution is simple - install .NET! lol however the company I work for is quite massive (corporate size) and our department is quite small and insignificant so if we want to install something like .NET on all the consultants computers it will take around 6-8 weeks! Now we desperately need to start using this mini program ASAP! Is there any humanly possible way to run a Visual Basic program without installing .NET? Is there some kind of file I can download and put in the folder of the mini program that will allow it to work?
View 2 RepliesRunning Pre-Compiled & Non-Pre-Compiled Webpages Under One Virtual Directory
Feb 21, 2011I've a requirement to have PreCompiled webpages and Non-PreCompiled webpages under same application. For example below is my structure:
/Bin
/Test1 (PreCompiled)
/Test2 (NonPreCompiled)
/Test3 (PreCompiled)
I would like these to have their separate "Bin" folders too if possible at all (I tried using "Probing" but I guess that's not allowed for web apps and defaults to "Bin" folder). If not that then definitely some ability for these to work together under one app/virtual directory because I'm not allowed to create another at any cost :(
Program Compiled With VS2008 On Pc With Only .NET 4.0
Apr 28, 2010I have a program in vb.net compiled with VS2008. When I run it on a pc with only the .NET 4.0 installed, I get this error:[code]
View 11 RepliesDetermine When A .net Program Was Compiled/built?
Jun 13, 2012I need to prove that a VB.NET program that I wrote was written at a particular time.
(the reason is an academic integrity investigation where someone copied my code).
I have all the code on my disk including the debug and release folders, with my username in the build paths.
Are their addition things I could do, such as looking in the binaries?
Error After Installation Of Compiled Program
Jun 2, 2011I've written an app in VB 2008.using .net framework 3.5
It uses a MySQL database.No app.config file for settings, I had this, but removed it when troubleshooting :S
Error is this.
When I compile in VB2008, it runs flawlessly, no issues.I added a setup wizard so I can distribute the project as well.When I put this on a client machine, it installs fine, but on the program run, this exception is thrown.[code]...
Split String Error In A Compiled Class?
Apr 1, 2010I'm having some trouble compiling some VB code I wrote to split a string based on a set of predefined delimeters (comma, semicolon, colon, etc). I have successfully written some code that can be loaded inside a custom VB component (I place this code inside a VB.NET component in a plug-in called Grasshopper) and everything works fine. For instance, let's say my incoming string is "123,456". When I feed this string into the VB code I wrote, I get a new list where the first value is "123" and the second value is "456".However, I have been trying to compile this code into it's own class so I can load it inside Grasshopper separately from the standard VB component. When I try to compile this code, it isn't separating the string into a new list with two values. Instead, I get a message that says "System.String []". Do you guys see anything wrong in my compile code? You can find an screenshot image of my problem at the following link: click to see image This is the VB code for the compiled class:
[Code]...
Error In Program Which Just Compiled With Microsoft VB 2008
Aug 13, 2010Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.
Invalid Argument=Value of '10' is not valid for 'SelectedIndex'.
Parameter name: SelectedIndex.
Include A Referenced File Within Compiled Program?
Mar 30, 2011In my code I reference certain excel files by listing the paths and names within my code. I've herd that if I put my excel files in bin/debug/ then I no longer need the path and can simply refer to them by name. This has not worked out well for me. how I can add a file to my project reference it by name in the code and have it compiled with my program so that other's (without that paticular path) can use my program. I have also added them as an "Item" and have their properties referenced as an "Embedded Resource", but still no luck. Maybe i'm just calling them wrong? Below is my code....
Dim file1 As String = "C:
etworkpathmyfile.xlsx"
Dim hdrftr As Object
[Code]....
Error "debugger Cannot Convert Data Type From String To Double"
May 7, 2012I am using two textBox's. The first to enter the data. The second to convert to answer the program complies with no error, the debugger cannot convert data type from string to double.
[Code]....
why does the program not convert the textbox txtFahrenheit from string to double?
Running 32bit Compiled Program/DLL On 64bit Machine?
May 20, 2011I have some programs written in VB2010 using functions from a DLL. I have compiled and run these programs on a 32bit XP computer and a 32bit Win7 computer and have had no problems accessing the DLL.I have published an installation of these programs and tried running the install on a 64bit Win7 machine and the installation is performed correctly. It installs the programs and copies the required DLL into the same folder. the problem is that whenever I run the software and try to access the DLL I get errors.
The error says something like:
An unhandled exception has occurred in your application. An attempt was made to load a program with an incorrect format. (Exception from HRESULT:0x8007000B)
If I click past it the software runs and all of the forms are loaded properly, but anytime in the software if I try to access the DLL I get the same error.I am declaring functions in the DLL like this:
Public Declare Function OpenDriver Lib "OP815M.DLL" (ByVal handle_Renamed As Integer) As Integer
I have also tried placing the DLL in the system32 directory and also the sysWOW64 directory and that did not help as well.I do recall that hardware drivers need to be properly signed and pass the Microsoft Logo testing. Must I get the DLLs I am using properly signed?
Edit: Also it might be fair to mention that I have used the DLL with another program written in C, which would run in the DOS command line in Windows and it correctly accesses the DLL on a 64bit machine, but just when run from the DOS command line in windows.
Error While Running Compiled Program - Unhandled Exception Has Occurred In Your Application
Jun 30, 2010I'm making a program from witch one could run an application with different credentials.I can compile the program successfully, but when I press the button to run the program I get the following error: Unhandled exception has occurred in your application. If you click Continue, the application will ignore this error and attempt to continue. If you click Quit, the application will close immediately.The system cannot find the specified file.The code behind the button is as follows:
Dim myProcess As System.Diagnostics.Process = New System.Diagnostics.Process()
myProcess.StartInfo.FileName = "c:
un.bat /user:kreathyr c:getlogin.exe"
myProcess.Start()
Getlogin.exe does nothing but show the logged in username and run.bat utilizes the runas command.
VS 2008 Goto Debug Program Get Error 'Conversion From String' To Type 'Boolean' Is Not Valid
Jan 27, 2010i have a problem with my code: [code] At the bold part, when i goto debug my program i get the error "Conversion from string "TrueFalse" to type 'Boolean' is not valid."
View 3 RepliesExplicit Conversion - Convert The Variable D From Double Type To Integer Type And Store The Result As 132
Oct 22, 2009I want to use explicit conversion (CType function in VB.NET) to convert the variable d from double type to integer type and store the result as 132.
Imports System.Console
Module Module1
Sub Main()
[CODE]...
This is my code. But Visual Basic tells me an error: Error1Type 'i' is not defined.C:\Users\mihaispr\Desktop\Conversie explicita\Conversie explicita\Module1.vb1922Conversie explicita
Convert Anonymous Type To Strong Type For Grouping Query?
Aug 30, 2010I've pieced together some information from other posts but I'm stuck. The first part works fine. Basically I query the database using LINQ and then I loop through the results generating a report.
[Code]...
Convert Ebcidic String To A Ebcidic Byte Array In Program?
Dec 27, 2010I ahve String which i have formed in EBCIDIC format.Now This EBCIDIC string has to be converted to EBCIDIC Byte array.[code]...
View 1 RepliesConversion From Type 'String' To Type 'String' Is Not Valid
Dec 21, 2009I'm in the process of porting an old excel addin that was writen in VBA to VB .NET. The Excel addin interacts with a number of external com objects. The code sorta looks like this:[code...]
What I'm trying to do is read the string from the COM object and get it in durr for use later in my program.
That second line results in the exception posted above. If I try casting with CStr/CType I get the same exception.
The visual studio watch window reports the type of hurr.getString as a "System.__ComObject" whereas the VBA watch window reports the type as "Variant/Object/String".
Microsoft.VisualBasic.Information.TypeName(hurr.getString) says the type is "String".
String Split - Error Value Of Type '1-dimensional Array Of String' Cannot Be Converted To 'String'
Mar 11, 2010my code is :
[Code]...
The error is Value of type '1-dimensional array of string' cannot be converted to 'String'.
DB/Reporting :: Conversion From Type DBnull To Type String Is Not Valid When Inserting A Record
Mar 22, 2010I'm trying to add a new record to my database but i keep getting the message - "conversion from type DBnull to type string is not valid". I think its something to do with the Employee ID when VB attempts to save it to the database my code is below
Imports System.Data.OleDb
Public Class Add
Private Sub DisplayRow()
[Code]....
Error: Microsoft.VisualBasic: Conversion From Type 'DataRowView' To Type 'String' Is Not Valid
May 25, 2011I now have SQL Parameters set up and I'm using them to save/delete/add my data. This all works well, except when it's trying to save a combobox to the datatable it appears with the error above.Majority of my comboboxes have datasources, and the valuemembers of these are the actual list items, not the ID's of the list items.I'm not sure why this error could be happening, I'm fairly sure I've connected everything to the binding source correctly; I've checked it a few times.Does anybody know what the cause of this could be? I've looked around a bit and I haven't found much
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