I don't know enough about VB.Net yet to use the richer HttpWebRequest class, so I figured I'd use the simpler WebClient class to download web pages asynchronously (to avoid freezing the UI).
However, how can the asynchronous event handler actually return the web page to the calling routine?[code]...
I'm trying to download a WebPage as a String, which works, however, I can not parse each line of Html at a time. I can either, Parse each Character, or parse the whole thing as a single String. Here's my
I have been given an ASP.Net assignment at work because I had taken a few courses a couple of years ago. Currently, there are no ASP.Net programmers for me to ask here and I have searched several places (including Pro ASP Net book) to find a solution but have come up empty handed.
I have a class named spErrors which takes the values passed to it. Values passed include the offending page,function/sub, and other values and stores them in property values, then calls Response.Redirect("Errors.aspx") from the page's code behind page. In Errors.aspx, the values of the error/exception trapped in the Catch statement are displayed. This works fine from a web form. My question is, how do I call a web page from a class module?
Each class module has the ErrorHandler() procedure that passes these values to the class object. In the class, there is a Write Only property named Redirect and a method called Execute() which is used to display the error page if the error occurs in another class module. Since Response.Redirect() does not work in a class module, what namespace is needed in order for this to work?
Here is the code I'm using.
In the Catch block. Catch ex As Exception Err.Description = ex.Message ErrorHandler(Err, "function name")
as per usual i am a little confused. I know DownloadStringAsync runs on a threaded pool with a default min and max threads limit, but what confuses is how would i call DownloadStringAsync say for example ten times.Example.I have an array with 10 URLS. Surely i would not use a for each loop of the array index to pass the url address while each time calling DownloadStringAsync(New Uri("someArray(index)") surely we can pass say a range of items from the array and let DownloadStringAsync decide on the threaded pool how many to process each time?
I am trying to build a code to get the website asynchronously using webclient.download stringasync..I want to pass the data thus retrieved from dowloadstringcompleted to another function.[code]My problem is that I am not being able to pass on the values as StartDownload gets completed, while data is still being retrieved.
i am developing application for windows phone and i want to read an xml from the web so i am using on page loaded event :
Dim cl As New WebClient AddHandler cl.DownloadStringCompleted, AddressOf cl_DownloadStringCompleted cl.DownloadStringAsync(New Uri("demo.com/1.xml",UriKind.RelativeOrAbsolute))
and on cl.DownloadStringCompleted event :
Dim doc = XDocument.Load("demo.com/1.xml")
but for some reason i crashes ! the bug must be that i have not to use URI : "demo.com/1.xml" , but some else?
i have an aspx page with vb.net back end. in that page i get names and url's from the database depending on different conditions. My requirement is that when i get the url, the code should then use that url and have that webpage in a small preview form on my existing aspx page. so basically i have a table as follows -
I making a webpage with the help visual basic. I wanted to put a flv video in it and i used flash control for asp.net [URL]. I made the player in flash told it to download the video from the sever. Now when i put the player on the webpage and put the webpage on the sever it cant play the video. But when i just pres the the player which is in swf format it works. It can download the video. But when i put the player on my webpage it cant.
I have a C++ application exe that uses a C++ dll. I don't have the source of this C++ application and cannot rebuild it. But I know that it uses the traditional LoadLibrary and GetProcAddress to access individual functions in the dll.For some reasons, I want to replace the C++ dll with a VB.NET dll. The dll is not and ActiveX and is therefore not registered.I think I cannot use a class but a module since the C++ exe application does not expect any class in the dll. In all my attempts, I could not have the inner functions of the VB.NET to be called by the C++ exe.How should I write the VB.NET dll?
I do realize that a number of questions regarding calling a DLL from vb.net have been raised. I have implemented the DLL from vb.net. I would like to know if the calling procedure is correct or should I be calling the DLL in a different way?
C++ DLL prototype
extern "C" int FitCurve(int solid_or_fluid, int prop_id, int fit_id, int N_points, int N_terms, char *file, double *x_data, double *y_data)
I'm not sure whether this is a VB forum question or a C++ question, but I'll try here first. I have an API library written in C++ (including source) which compiles to several DLLs. I want to call the functions in the library from VB but I can't get the parameter passing right.
[Code]...
The above example runs but returns nothing. If I change DeviceName to ByRef, I get protected memory errors.
The full library and documentation is available on the internet if anyone would like to download it and I've successfully compiled it with VS2010.
I have followed instructions on Best way to use a VB.NET class library from a C++ DLL? but being new to VB I don't know if I've got the VB part right let alone the C++. here I'll correct the code below for posterity's sake!
Here they are: VB first; the project is a Class Library, all settings default except that "Register for COM interop" is switched on in the project properties.
Public Class Class1 Public Sub New() 'do stuff
[Code]....
is the VB correct? Do I need to add anything like an interface to it? Assuming I want to call it over COM not C++/CLI, how do I do that. (This seems like the logical choice as the client already calls other stuff over COM; however, I'm not sure where to get the IDispatch pointer from, in my other code it's passed to me by the client). If I went the C++/CLI route, when moving up from toy project to actual implementation, that would mean changing my existing C++ code from "no clr support" to "/clr" - is that likely to break it?
I have a C++ application exe that uses a C++ dll. For some rasons, I want to replace the C++ dll with a VB.NET dll. The dll is not and ActiveX and is therefore not registered.I cannot use a class but a module since the C++ application does not expect any class in the dll. In all my attempts, I could not have the inner functions of the VB.NET to be called by the C++ exe.How should I write the VB.NET dll?
This might seem like an insanely easy question, but I cant seem to find an answer anywhere to it. I'd like to think that I am decent at VB but while I was learning javascript the other day I found something that seemed awesome and now I cant figure out how to do it in VB.in javascript it looks like this
var someValue = getThatValue()Its both calling and setting the value from the getThatValue() sub. what is the VB equivalent?
In C# I can do this:new SomeObjectType("abc", 10);
In other words, I can call new without assigning the created instance to any variable. However, in VB.Net it seems I cannot do the same thing.New SomeObjectType("abc", 10) ' syntax error
I have a need to create a Tcl extension that calls a managed .NET DLL/Class Library. Currently, the structure of my application is Tcl > DLL Wrapper (C++ CLR) > .NET Class Library (VB.NET), where ">" represents a function call.
My VB.NET DLL just takes a value and returns it back, keeping it simple for now. In the end, this will do some more advanced stuff that makes use of some .NET functionality.
Public Class TestClass Public Function TestFunction(ByVal param As Integer) As Integer Return param End Function End Class
My Tcl Extension (C++ CLR) creates an object of the type above
int TestCmd(ClientData data, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]) { // Check the number of arguments
[code].....
If my VB.NET DLL is in the same directory as my extension DLL, the extension crashes when it instantiates a TestClass object. I've noticed if the VB.NET DLL is relocated to C:Tclin, the extension will find it, and TestCmd can be called just fine. The problem is that this will eventually need to be deployed across a number of PCs, and it's preferred not to mingle my application's files with another application's.
The cmd file calls a web service that is used to select specific data. When I run the .cmd file manually (as in clicking on it) it runs correctly an saves the file with the information in the appropriate location. However when i try to do this with the .Net app the file is saved however there is no data in it. Why is it when I physically click this same .cmd file with my mouse it works but not when I call it from my application.
I have used the PInvoke Signature Toolkit to create VB.NET function definitions for three fairly simple C functions contained in an external DLL. The problem is that two of the parameters are structures so pointers need to be sent and one structure (fileview) is undefined.
The structure of fileinfo is defined so I can create a structure definition in VB.NET and create an IntPtr to that structure with Marshall.AllocHGlobal. And then I can use Marshall.StructureToPtr to copy the data and do the inverse when the data is returned.
I'm having some problems calling a C function from a DLL. The function is returning -101 which translates as a "bad parameter". The values I am passing have been returned from another, successful function call, so my current assumption is that I've built the structure incorrectly.The function definition is:
int sm_switch_channel_input(struct sm_switch_channel_parms *switchp) Parameters *switchp (a structure of the following type): typedef struct sm_switch_channel_parms {
i just wanted to calafiy i know how to call a different sub and everything but i wanted to know if you could call a different program all together.
say you have on the first WITCH POWER DO YOU CHOSE. then they hit NEXT and it takes them to a whole new layout and program like saved in a different folder.
i think you do this like you would with webpages
Call ../folder/folder/frmbladeda
if thats wrong or there is an eazyer way also would i do the same thing with varibles like how you do Call addtogether(strone, strtwo) addtogether would be the private sub and strone and strtwo would the the varibles in that said sub.
make sure i want to call a different program like 3 folders away
in a DLL that takes a pointer to a structure as a parameter.The C and VB code is as follows.Am I passing the structure in calling the DLL correctly? I am asking because the API call returns a valid error code indicating error opening the com port specified. I tried all valid ports (com1 on a Vista 32 machine with a USB-Serial device and com1 defined in device mgr, com1 and com2 on a desktop with winxp and 2 real serial ports).I dont have the code for the DLL and cannot debug into the DLL code.
I'm sure this is a pretty simple question but I can't seem to find the answer on Google. Say I've got a function that does some stuff and returns a string. I can assign its return value to a variable:
Dim result As String = MyFunction()
But sometimes I want to perform the actions within the function but I don't care about the return value. I know I can simply call the function from code.
Sub Main() ' Code MyFunction() ' More Code End Sub
This works and does exactly what I need it to. My question is - are there any issues or pitfalls in doing this? Particularly I want to make sure I'm not introducing any performance or memory leak issues.