Is There A Cost To Using Managed (.NET) Components Inside COM+
Nov 4, 2010
Our company has relied heavily on COM+ components to centralize our DAL code and take advantage of the ability of COM+ to handle transactions and connection pooling. When we started using COM+, it was just with VB6 DLLs and always through late-binding so we could take advantage of DLLs being hosted on a different server.When we started moving to .NET in 2005, we ported our DAL functionality to .NET and continued to use COM+ and late binding to host the components. We would instantiate the objects like so: objBalLauncher = CreateObject("NETBLL.Launcher", "\" &strCOMPlusServer Name)I noticed that CreateObject seems to be for ActiveX COM components, so this has me thinking about two things:If COM+ was designed for unmanaged components, is there a cost to using COM+ with managed .NET DLLs?Is there a cost to using CreateObject() to late-bind to an assembly from within .NET code? Does this force your code to cross the managed/unmanaged barrier to communicate with the DLL? While I would be interested in hearing about alternatives to COM+ (which I'm sure are available by now), I'm most interested in hearing about what expense I incur from using managed DLLs within COM+.
I am running into trouble with some code I am doing for an assignment. The section within the apostrophes (If Then Else) is the section that I am having trouble with. When the user selects a seat type and then clicks the compute button, the wrong cost is displayed instead of an accurate cost.
Option Strict On Public Class frmTickets
Private Sub btnComputeCost_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnComputeCost.Click Dim intNumberOfTickets As Integer
How do I code the total cost to give me a pound sign with the total cost at the moment when the total comes up for an example it gives me 3.6 when I need it to show £3.60 here is the code I have so far. [code]
(1) I've read a lot of questions about IDisposable where the answers recommend not using Finalize unless you really need to because of the process time involved.What I haven't seen is how much this cost is and how often it's paid. Every millisecond? second? hour, day etc.
(2) Also, it seems to me that Finalize is handy when its not always known if an object can be disposed. For instance, the framework font class. A control can't dispose of it because it doesn't know if the font is shared. The font is usually created at design time so the user won't know to dispose it, therefore finalize kicks in to finally get rid of it when there are no references left. Is that a correct impression?
below is the code I am working on. It is for a hospital cost form.
[code..]
I have a working version, but it doesn't meet the requirements completley.(I can post that if you need to see it) I am redoing this project and I am so stressed out. I may be overlooking something!
I am writing classes in VB.Net (both managed). The main class "A" creates an instance of "B". Class "B" must call a method of Class "A". I need to know two things (syntax, etc...):
1. How does class "A" tell class "B" what method to call?
2. How does class "B" call the method?
The method must pass back an array of Shorts (in this particular example), either as a return value, or as a ByRef argument.I don't want to use an event if I don't have to. The execution is timing critical. (I assume event handling involves a lot of overhead by the operating system, but I may be wrong.)
I am trying to calculate a total cost from an elapsed time. Dependant on how long the time is, this will calculate the total cost. It has to be 3 to every hour. The elapsed time is displayed in label6 in "hh:MM:ss" format and the total cost needs to be displayed in label8.
I am creating a code for a school project that calculates the shipping cost for a package. In this program the user enters the weight of the package ( in pounds ) and selects the destination of the package. The application with determine the cost of the shipping. The destination of the package can be the US continental, Hawaii or Alaska. If the package is going to Hawaii a 20% surcharge is added to the shipping cost. If the package is going to Alaska, a 26% surcharge is added the shipping cost.
This is my code thus far. When applying my weight in pounds and selecting the destination I still keep getting 0.0 for the total. Public Class Form1 Private Sub textboxpounds_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles textboxpounds.TextChanged End Sub Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)[Code] .....
Here is a screenshot of the GUI Uploaded with ImageShack.us
I'm have successfully did a shortcut "+" and "-" button to increase and decrease the qty ordered. But by doing so, i now have problem tabulating the cost for each item. Below is the print screen for my application. You will realised that the Lamb tandoori which is going for $3 cost only $21 after increasing the quantity ordered using the "+" button.In addition, i have created different list boxes for different food categories.Each category's food items is selling at the same price.
My project, is something that could be used by an opticians (well in theory anyway)I have a customer being selected, eye measurements etc..Then I can enter in data (into textboxes):
TextBox1. Frames Stock: #12345 TextBox2. Material Used: Glass / Plastic TextBox3. UV Filter: Yes / No
I was trying to make a calculator which takes the amont of copies you want to make and it tells you the cost. Then you type in the amount you want to enter and if its less a message box comes up saying "please enter more money". I've had a few problems
1. when i use formatcurrency the program crashes for no apparent reason
2. if i calculate cost without entering any copies then it crashes (ive tried putting a msgbox in but it crashes anyway)
3. if i get the msgbox to come up saying "Please enter more money" i had to remove the formatcorrency tag.
I have absolutely no background on programming in C (or any other unmanaged languages for that matter) yet I would like to use the GetBestInterface function from the IP Helper API in my .NET application. I tried to understand how P/invoke calls can be used to make calls to native methods, but there are many things that just don't make sense to me (like how types in managed code map to unmanaged types).
Is there an alternative function somewhere hidden in the System.Net namespace that does roughly the same thing? Or could I write my own alternative using existing base classes combined with some magic? Because that's basically what it seems to me: magic. There is no real explanation for how the method accomplishes what it does as far as I can tell...
I just discovered the LocalEndPoint property on the System.Net.Sockets.Socket class which I think could be quite useful in this. To my understanding it will do the best-interface-picking on my behalf and I'll just need to get the NIC that corresponds to the local endpoint.
I am having a very strange memory leak that seems related to databinding. It is very hard to reproduce, so I won't post any code here to do so, but will just describe the problem.We have data entry forms which have controls which bind to custom business objects through a BindingSource object.
I have a class assignment where i have to calculate the total cost of a parking garage from hours but i have to do it with a method function. So this might be a stupid question but can you read the user input values from a textbox in the function itself or do they have to be read in and recalled from the Private Sub Button1_Click section?
Create an application that calculates the total cost of a stay in a hotel in the North Carolina mountains. The application should accept the following in terms of input:Month of Check in Length of Stay (in Nights) Number of Persons Room Service Charges Phone Charges Other Charges If the check in occurs in November-March the rate is $89/night. April-August is $99/night and September-October is $109/night. $10/night should be added if more than 2 people are in the room. More than 4 people are not allowed in the room, and a traveler can only request 1 room. A 15% tax should be added to the room rate and 10% tax added to all room service and other charges. No tax will be added for phone charges.
The program should use a function to calculate the total charges for the visitor's stay and output it to a label. There should be buttons or menus to calculate the total, clear the form, and exit the application.At least one of the button should call a sub procedure which performs its function. I don't understand how to set this program up and I'm not sure what it means.
I certainly hope I don't aggravate you with what is certainly a very simple code problem. I have never programmed before, but I do have a background in tech support, etc. I have an assignment to do and it's frustrating to wade through the information out there to find exactly what I need and nothing more.The assignment has 3 parts, one of which i've done. We are to do the same function in both javascript and VB. I was able to take a sample we did in class that caluclates a 10% discount and modify it so it calculates the total. Now, I have to modify that into a VB sln file. then write about the differences but that part will be cake.
I am working in Visual Studio 2008 - that program is new to me as well. When I created my login and it asked what VB I'm using, I did not know but under theu of VS, it says VB 2008.hat I attempted to do was to take the instructor's sample discount code and modify it for the new purpose, but an error was generated. This is the sample code I started with:
I have event Button that creates text box in run time.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim textbox1 As New TextBox static Dim shiftDown As Integer static Dim counter As Integer
[code]....
All the text boxes that has been created displayed in GroupBox control dynamically. how GroupBox control size can be managed according to quantity controls inside it.
I have a .Net application (VB in particular, although I would this to be as language agnostic as possible) that uses a COM object (made in C++). I need to implement a event in COM that passes a char array from C++ to .Net. I guess I need to convert the array to a managed array; How can I do this?
I am well aware that finalizers are typically used to control unmanaged resources. Under what circumstances may a finalizer deal with managed ones? My understanding is that presence in the finalizer queue will prevent any object, or objects strongly referenced thereby, from being collected, but it will not (of course) protect them from finalization. In the normal course of events, once an object is finalized it will be removed from the queue and any objects it references will no longer be protected from collection on the next GC pass. By the time a finalizer is called, the finalizers may have been called for any combination of objects referred to by the object; one cannot rely upon finalizers being called in any particular sequence, but the object references one holds should still be valid.
I am trying to develop a dll in VisualStudio2005 in vb.net that will communicate with a spectrometer attached to the USB port of the computer.Now the dll exists in C++ and it works like a charm. It is unmanaged code.Now if I try to translate this code in VB.net (because our app is in VB and my boss wants it in VB for maintainability) I have problems.
First of all, I am trying to create a file to open that port. The code in C++ looks like below and it works. Needles to say I tried to call the C++ dll from our app and it works. If I call the vb dll it doesn't. It gives me "access denied" no matter what I tried. I am not sure if my CreateFile is wrong or it's .net. I read somewhere that I need a manifest file included in the dll? Has anyone experience something like this? Why would i get "ACCESS DENIED" all the time?
// close and clear current stuff ClosePort(); swprintf( sDevice, L"\\?\usb#vid_0765&pid_%s#******#{%s}", Device, PRIVATE_IID_STR );
I need to write a DLL in C that is used a plugin for an existing application.The DLL has to be compiled by the Visual Studio 2008 compiler with the following options.[code]It's then linked to applications library's.What it actually needs to do and what's causing me the issues is that within one of the methods it needs to pull data from a sql server 2008 r2. From what I've seen today you wouldn't be able to do this directly in C as SQL Server past 2005 is designed to communicate with CLR languages( C#, C++, VB.Net).It was suggested that I handle all the database communication with a VB.Net dll and then call said function from within the C dll. Most of what I've found on the topic of calling managed dll's from unmanaged code has talked about pinvoke or com wrappers and mainly from the perspective of c++.
In My application, I have an MDI form. From MDI form I open all forms as child forms. I have implemented IDisposable for all large objects like file stream DB connection etc. In the Form_Disposed event I dispose all unmanaged objects. After the child form is closed, all unmanaged objects are disposed but managed objects (controls and form) are not disposed and still in memory. I find it from .Net Memory Profiler ([URL]).
So I have write code to remove all event handlers of all controls and form. Now, When form closed, dispose is called and all event handlers and controls are disposed, but controls and form are still in memory.
I am using a slightly modified version of this code. to create a mission critical application. That files that will be encrypted are very important. This has to be done from scratch because there are some other things that has to be done along with this. How secure is this? Its impossible to crack this encryption right? [Code]
