is there a way to check how many delegates are attached to an event, let's saymybutton.Click has 10 handlers, 5 by using the Handles keyword and another 5 added by using the AddHandler method (well this is not the point, then point is that i do not know how many handlers there will be). and i would want to create another button that had all 10 handlers of mybutton.Click attached to its Click event as well.
View 6 RepliesI have two objects - one that contains some code with will fire an event, and one that contains the handler for that event. I can't "AddHandler" in the Load of the first object,because an instance of the second object doesn't exist yet. When I raise my event, I want to check to see if a copy of object2 has been instantiated (easy to do), and if a handler has been attached to the event yet (not sure how to do this).I'm also open to another recommendation about how to do this instead. If I do my AddHandler in Object1.Load, and Object2 doesn't exist yet, then it will never handle my event, even if I create it later.Right now, in the code that fires the event, I've just resorted to doing a RemoveHandler and then an AddHandler every single time the event is raised, and then I know I'll attach when the object finally exists, but I know this is a crappy method.
View 3 RepliesI can come up with, if I understood the solution better, I could probably phrase a better subject line.[code]...
View 2 RepliesI was going through tutorials and found the topic of Events and Delegates. However, I fail to understand why should this be required ? Instead of having to raise events, can't one just call the necessary procedure ?Sorry for posing this basic question. Any replies or even links to existing posts are welcome. [Also not sure if this question strictly falls under VB.NET category.]
View 4 RepliesI'm looking for a reference that can explain the concept and use of the DataReceived event and Delegates subject.The reference has to be pretty simple as I'm an "old dog attempting to learn a new trick". I'm not ignorant of things programming, but am ignorant of things dealing with serial communication in VB2005.I already have a couple of O'Rielly books ("VB2005 Cookbook", "VB2005 Desktop Reference") and I have a book that deals with serial communication from a Jan Axle-something. Neither O'Rielly books have any info, and the Axle-someting book's remotely related examples are too confusing for this slow learner.
View 6 Replieswell i want all my textbox's event- keypress should be called by using Delegate
The Function i need to preform on them is only Numeric
My code
Public Delegate Function mydelegate() As Char
Public Function key(ByVal e As System.Windows.Forms.KeyPressEventArgs) As Char
Dim ch As Char = e.KeyChar
[Code]....
The problem comes when i use this code it surely gonna restrict me entering the alpha characters but i m facing problem is i can enter only a single digit number
i.e when i try to enter 45 it's simpley don't expect it only value which it is accepting is [1],[2] what i want it should accept the value's in two digits,three digits and so on..
I have a listbox binded to a list of objects. For each list item I wanted to have a rectangle whose fill color is determined by a few properties of the binded object. So I did the following:
Made sure INotifyPropertyChanged was implemented on my object.Created a class to expose the properties I am interested in as attached properties.Binded the properties of the object to the attached properties of the rectangle Created a style that uses triggers to set the rectangle fill based on attached properties.
This works, but only the first time the property of the object changes. After that, the attached properties do not seem to be receiving notification when the data object's property changes. I have double checked and my data object is raising the INotifyPropertyChanged event.
<Rectangle Style="{StaticResource RecordStateRectangleStyle}"
Width="10" Height="10" Stroke="Black"
local:RecordAttachment.RecordState="{Binding Path=RecordState}"
local:RecordAttachment.IsDeleted="{Binding Path=IsDeleted}" />
[code]....
What are Delegates and Multicast Delegates in VB.NET? How do I use them? provide a simple example to illustrate the concept.
View 1 RepliesI've been wondering how to do that for a while. (I never really needed it so far ). I wanna make e.g. a simple alarm script (waits for 6.30 am and makes a beep). The only way I could think of it is make a loop in the main function which loops until 8 hours later. Is there any other, more civilized way (probably event?)
View 6 RepliesIs there any better performance by checking for a true value like this:
[CODE]..............
Than like this:
[CODE]..............
I have a class that I want to be serializable but contains a public instance of delegate that, apparently can't be serialized: [Code] Is there a way to make it serializable however?
View 4 RepliesI m using vs2008 with vb and sqlserver. I just attached a .sdf database file to my project. There is a form to insert data in products table and a dgv to show that data. Everything is working fine, i inserted the data and dgv is also showing the data. But when i tried to see that data from server explorer, thr is no data, table is blank. Then again when i run my project thr is no data in DGV also. So problem is that when i entered the data and retrieve back the data in dgv,evrythng is fine,but when i tried to see my data from server explorer, data is lost. Why data is not comtted to my .sdf ?
View 4 RepliesHow to i make a table like the one attached in vb
View 2 RepliesConsider these two functions[code]...
My question is: what is the right way to accomplish this to resolve the ambiguity so that I can pass value or references types and get overload 2, but pass Functions and get overload 1? Can I constrain the types in some way to make this happen?
I've been tinkering with Delegates, and now Multicast delegates. Every time I invoke two delegates It only displays one of the two delegates per invocation.
[Code]...
[Code]....
So func is a function that accepts a string and return a string. In practice, internally, func also utilizez text1, text2. In fact, func can even be a member function with access the object that owns it (something like me or this operator).
And all that can be accomplished without changing the signature of func? How do the compiler do this?
I am struggling to get the syntax for the reflection call GetCustomAttributes ... at least I don't seem to be able to get hold of the custom attribute which I've decorated a particular method with. The complicating factor maybe that I have passed that method into an extension method as a generic delegate. (The other, more likely, complicating factor is that I'm not sufficiently familiar with reflection or what happens when you pass a method as a parameter like this!)
The code appears to run, and when I step it, the count returned from the GetCustomAttributes is 1. I can't work out how to get hold of that custom parameter
[Code]...
is there a way to create an interface of delegates? Sub dostuff(byval arg1 as dele1)works, problem is that i have 8 delegates, so i will have to give it 8 signatures. that isn't so bad, but the problem is that when there are various combinations of signatures it gets real real bad.
Sub dostuff(byval arg1 as [Delegate])works, but it allows me to accept delegates beyond the 8 that i wanted (it's like declarign arguments with base Object)could i be able to do this:
Sub dostuff(byval arg1 as Idele1to8)
Is it possible to create anonymous delegates in vb.net version 8 or earlier? If so, could someone provide an example of the syntax?
View 2 RepliesI have a VBNET app to scan my Active Directory using WMI calls and return some basic informaiton such as Dell Model name, current user logged on, Dell Service Tag etc my issue is the app becomes unresponsive whilst it scans and i have to wait for it to finish looping before i can work with it, in the past a do events used to suffice
I think Multithreading is the way i may need to go, whats the best approach? I tried to use Delegates but it doesnt seem to have made any difference
below is my for next loop code that calls the functions, the last section "Private Sub Button1_Click" down is the Delegate code i attempted
[Code]...
Maybe I am just not reading the MSDN documentation correctly, but given a function that takes in one string parameter and returns type T, how can this be specifed as a shared function using Func()?
MSDN says Func(Of In T1, Out TResult), but all of their examples use the same data type, i.e., Func(Of String, String). I want to do Func(Of In String, Out T), where T is arbitrary (but I can constrain it if necessary by a base class). I want it shared/static at the class level, yet the encapsulating class will itself not be a generic class. It seems in this specific scenario, it's impossible to do what I want because the compiler would have no way of knowing what Type T is at runtime.
So is it possible to do generics on delegates or anonymous lambda expressions in VB.net (not C#)?
I am having trouble with getting a delegate to work properly.Here's my
[Code]...
What is the difference b/w Delegates and Events. I have little bit confusion. Where delegates are used, and when we have to used delegates. Can, you give some examples(both delebates and events) in vb.net.
View 6 Replies
How can I, download attached files from unread received mail , by VB code.
I am trying to achieve the look of the attached image using string.Format and PadLeft/PadRight but I have no success with it, anyone who could offer some help?
EDIT:The font I used is not mono-spaced and I am not inclined to use a mono-spaced font for this.
I am building a Windows Desktop software that will respond to SMS request and sending a SMS as reply automatically.
The software is ready and working just fine but it works only and only with Nokia Mobiles and the prerequisite is that Nokia's PC Suit has to be installed first before my app can work.
But now my customer wants to change his mobile so he wants me to change programming so that it works with any mobile.
change the .txt extension of the attached file to .rar 123.txt (595.23K)Number of downloads: 79 Its the whole Project file including a video in to illustrate the weird error! Since is almost impossible to describe the error! For all of you who will try to open the project using visual studio be sure to Import the files in the rar for model model file.txt and catalogue file.txt for catalogue
'Marios Solomou
Imports System.IO
Public Class DAC
[Code].....
I read from a text file to see what I need to add to my MenuStrip. Each line in the text file is a new item. When I read I add the new item's OnClick event using AddHandler to get its text when it's clicked. Here are my two subs[code]....
View 6 RepliesI am trying to get the names of the USB devices attached to a computer. I saw system.management would do what I need, but. It says its not defined and I cannot find system.management as a refrence.
I am building in VB2008. Can some one point me in the right direction?
Could anyone help me to find the template design for the above form ? or any toturial Video that teach step by step on how to develop such the above form please ? (Visual Basic 2010)
View 6 Replies