how to do something that seems that it should be simple.
I tried it on a larger project I'm working on and got an error, so I reduced it to the simplest possible that I could find:
Public Interface IF1
Event WakeUp(ByVal TheObject As Object)
End Interface
[Code]....
Im building a game with VB.NET I designed the core of the game in form1 window But now I need menus. How can I implement this without having 5 or so windows that I show() and hide() ? Doing that slows it down a lot and uses lots of memory. I tried tabs, but I don't want the tabs to appear, just switch. Whats the best way to implement multiple interfaces?
View 1 RepliesI'm dealing a problem in implementing interface for multiple class.
Assuming I have a class named Class Unu .
I created an interface called Test for those 2 classes.
The first class Unu has 2 data members(i=12 and j=12.17). When you run the program it stores the result on screen 24.17
The second class called Doi has 2 data members(a=20 and b=32.17).
What I want now is to do the same thing for data members a and b so that it stores on screen 20+32.17=52.17
My problem is that I want to be displayed also the result for the 2 data members for the second class on my screen. I implemented the interface on class Doi but I cannot see why he isn't displaying me the second result 52.17.
What I must add to my code to do that?
Here's the full code:
CODE:
Can any one explain the usage of interfaces to implement multiple inheritance in VB.NET.
View 6 RepliesIn .net, it's possible to use generics so that a function can accept arguments which support one or more interfaces and derive from a base type, even if there does not exist any single type from which all valid argument types derive. For example, one could say: Sub Foo(Of T As {IInterface1, IInterface2, SomeBaseType})(Param as T) And be allowed to pass any derivative of SomeBaseType which implements both IInterface1 and IInterface2. This will work even if SomeBaseType does not support Interface1 and Interface2, and classes which do implement those interfaces don't share any common ancestor that also implements them. This can be very convenient if one won't need to keep the parameter anywhere after the function has exited. Unfortunately, I can't figure out a way to persist the passed-in parameter in such a way that it can later be passed to a similar function, except perhaps by using Reflection. Is there any nice way of doing that?
The closest I've been able to come up with is to define an interface INest (perhaps not the best name-- thus:
Interface INest(Of Out T)
Function Nest() As T
End Interface
And for any interface that will be used in combination with others or with base-class "constraint", define a generic version as illustrated below:
Interface IFun1
' Any members of the interface go here, e.g. ...'
Sub DoFun1()
[CODE]...
A class which will support multiple interfaces should declare itself as implementing the generic ones, with itself as the type argument.
Class test123a
Inherits sampleBase
Implements IFun1(Of test123a), IFun2(Of test123a), IFun3(Of test123a)
End Class
If that is done, one can define a function argument or class variable that supports multiple constraints thusly: Dim SomeField as IFun1(Of IFun2(Of IFun3(Of sampleBase)))
And then assign to it any class derived from sampleBase, which implements those interfaces. SomeField will implement IFun1; SomeField.Nest will implement IFun2; SomeField.Nest.Nest will implement IFun3. Note that there's no requirement that IFun1, IFun2, IFun3, or sampleBase share any common derivation other than the generic interfaces inheriting from INest(Of T). Note also that, no matter how many INest-derived interfaces a class implements, it only needs to define one implementation of INest(Of T).Nest. Not exactly beautiful, but there are two nice things about it: (1) any concrete class which in fact implements the necessary interfaces can be assigned directly to a field declared as above, without a typecast; (2) while fields which chain the types in a different order are not assignment compatible, they may be typecast to each other. Is there any better way to store something in such a way that it's "known" to support multiple interfaces and derive from a certain base type? Given that one can write such code in a type-safe manner, it would seem like the .net 2.0 CLR could probably support such a thing quite nicely if compilers offered a little assistance.
I was looking through some legacy code we have and I noticed something that struck me as particularly odd.Say we have the concrete class TestClass. TestClass implements the interface ITestClass.What sort of behavior should I expect in the following case, then? (I didn't realize this was even possible)
Dim testClass as TestClass = Nothing
Try
testClass = New ITestClass
[code].....
I'm in the process of transplanting a unit test written in vb.net to the larger project written in c#. [Code] What is the best way to convert this event? Also, is this a good instance to use EventHandler<> to consolidate my arguments into a structure?
View 1 RepliesAM trying trap specific events for some controls on a form. i tried this, but its not fireing the events
[Code]...
EDIT I found out that am placing the control in multiple controls, on the form is a panel, inside the panel is different groupbox, these group boxes have the controls am trying to trap their events
I have multiple pictureboxes, is there a way to assign the same event and code once for all the pictureboxes ?
View 5 RepliesThe below sub-procedure isn't working like I expect it to. Basically, I have 9 fields on a tab control. When a user clicks in one of the fields, I wish for the field to "SelectAll" if their is a value already in the field. As you can see, the way I have it structured...only 1 field will do this, however, even this is not working.
Private Sub txtAddr1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtAddr1.Click, txtAddr2.Click, _
txtAddr3.Click, txtCity.Click, _
cmbState.Click, txtZip.Click, _
[code]....
IS there any method to perform two different tasks in one click event Like By clicking OK button i can do
1- Instantiate a new form
2- Add somthing to listview or can do something else
But these tasks not to me simultaneous. One task at a time Actually these taks will be performed simultanously, but i want one task to be performed at a time, not both?
I am trying to use multiple handles to trigger one event but I need each handle to effect the event differently. I feel like this should be simple. I want to use a Select Case to select the alteration but I can not figure out how to identify the handle used and convey that to the Select Case.
Private Sub Event(ByVal sender As System.Object, ByVal e As _
System.EventArgs) Handles Button1.Click, Button2.Click
Select Case handles[code].....
I am creating a program using Visual Basic 2010 Express.
I want to make a Sub handling both MouseHover and MouseLeave events. Is this possible? And if possible, how do I differ between MouseHover event and MouseLeave event?
I had a question about handling multiple events in a sub, like this:
Private Sub Form1_MouseUpOrDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseUp, Me.MouseDown
'do something
End Sub
Once the sub is called, is there any way to tell which event called it? (Whether it was a MouseDown or a MouseUp event?) Right now, I am doing a work-around as follows... having each event call the same sub and pass the info in. But it would be nice to not have that overhead.
Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
ExecuteMouseUpOrDown(EventTypes.MouseDown, sender, e)
End Sub
[CODE]...
Don't use ACCESS, EXCEL, or a TEXT FILE as a database. If you want your program to use a "local database", without any of the hassle of setting up a MS SQL or MySQL server, just click this link: >>> SQLite <<<.
I am using VB2010 Express to create a Windows Form.
I have been able to add an event handler to a single textbox to respond to the ".Leave" action.
Now I want to take multiple textboxes and use them as a single control and use the same event handler.
Eg. If TextBox1, TextBox2 and TextBox3 are grouped as a single control nothing would happen in those boxes until focus went to any other control on the form.
Is it possible to do a multiple records editing by linqtosql method in one click event? What I've been trying to do is to edit all the names in the table which are having the same account number. I was able to edit but only one name has been edited and the rest are not.
The codes I used.
Private Sub Button2_Click(------------) Handles Button2.Click
Dim accnt As String
accnt = Textbox1.Text
Dim db As New memrecDataContext()
Dim editrecord = From mem In db.Table1s
[Code] ......
Why is it these codes could only edit records in one datarow?
I am currently making a game with multiple levels when you complete one level the form hides and shows the form for the next level. But the keydown event doesnt work on the second level. How can I make it work?
View 1 RepliesI have this code. credits to jmchiney. My goal is when I press a certain key, the picturebox corresponding to that key should be moved to a certain location. Exactly like in the text twist game.
I have a code running and doing what I want but It is only applicable for single letter. For example the word alabama. all letters without duplicates are placed properly but for letter a, only one letter a is being accepted and moved. that goes for all letters.
Here is the
Dim pb As New PictureBox
Select Case (e.KeyChar)
Case CChar(letterPicbox1.Tag)
[Code].....
Another one. when a certain letter is already placed to the location I set and once I press again the same letter, the location changes. What I want is when I already gave pictureboxA a location and then I press "a" which correspond to pictureboxA again it should be stationary and check if there are other letter "a" in my pictureboxes and move the next detected letter "a" to the next position. Like i said. just like text twist game.
I'm trying to prevent a sub / function from firing multiple times on the same event.My app is for handling inbound phone calls (tapi).The app is supposed to route calls based on the callerid number.
aircode below:
Code:
Private Sub OnNewCall(ByVal sender As Object, ByVal e As NewCallEventArgs) Handles tapiManager.NewCall
if newcall.callerid = "5551001" then
redirect(newcall)
[code]....
If callA.callerid = "5551001" then redirect(callA)but, once it is redirected to the new extension, do not then grab the call from the new extension and try to redirect again (resulting in infinite loop).I realize I could use an integer as a counter, but the problem is, I might actually get more than 1 call at the same time from the same callerid number. And, all the calls would need to be redirected (once).the calls do have properties like (which are unique identifiers to each call):
Code:
phcall.id and phcall.hashcode
I'm thinking I need to put that unique id into a temp var / array to run a check against to see if it has been redirected, if it has then skip, if it has not then redirect.The app would run 24x7, and I don't want the temp var / array to get too big, and would want to have it clean automatically (up on a timer maybe?)(I'm guessing it would be a dynamically growing array.)
Is there another way to handle the leave event of multiple textboxes other then coding in each event handler? I may not be using correct terms instead of doing this: (Existing)
Private Sub leveladjstvaltxt_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles leveladjstvaltxt.Leave
If Me.leveladjstvaltxt.Text <> "" Then
Dim levels As Integer = CInt(Me.leveladjstvaltxt.Text)
Me.leveladjstvaltxt.Text = Format(levels, "#,###")
I have 30 TextBoxes all need same formatting , so I was trying to come up with something like this: (trying)
For Each ctrl As Control In Me.Controls
If TypeOf ctrl Is TextBox And ctrl.Text <> "" Then
Dim val As Double = CDbl(ctrl.Text)
CType(ctrl, TextBox).Text = Format(val, "#,###")
End If
I am stuck though and don't know where I would place that code if this is something that is even possible. Only thing I can currently think of is in the leave event which defeats the purpose, I wanted to avoid having to place the code in 30 different textoxes leave event.
how to have all forms have the same on closing event with the exception of one form (Form1). I want the forms to show Form1 when one of the other forms is closed. I know there is a way to do it, I just can't work out how.
My code at the moment assumes that each form will have a boolean declared on it as false that will only turn true if you use a legitimate way off of the page (i.e. a regular button on the form). If you instead click the exit button on the title panel it will find the boolean is false and show Form1.
So the only problem I really have is getting the code to apply to all forms without writing it for all of them.
I have many textbox controls and they are named as txt1.text, txt2.text, txt4.txt etc.I want to raise the event "Leave" when txt1.text leaves or txt2.text leaves.but with a single handler.
View 2 RepliesAre Interfaces used often? Need opinions.
View 4 RepliesI have an asp.net website to manage projects. I realized that when I click for the next project really fast and often it overrides all the next projects with the data of the first one. I call a method to save before to go for the next project. I use also a session variable for the id of the project.
EDIT: It looks like the sever stacks the save method and the ids but keeps the values of the first project in the controls this is the ajax that calls a server method to get the id and set it in an hidden field:
[Code]...
I have a Devexpress Gridview that is linked to a delete, fetch and update stored procedure. The problem I am having is that when I run my program, select a row in the grid and press delete it fires the event multiple times. Specifically it deletes the selected row and then I re-fetch the data so the focus returns to the first row. Which is what I want.
Unfortunately it starts at the beginning of my list and goes down it row by row deleting each row it comes to. It then continues several more times after the rows are deleted. I know this because for each deleted row it asks me if I want to delete it. If I say no then the rows appear to disappear until I manually refresh it after the deleting is done. To make this even more random the second row always reappears after I manually refresh the grid.
[Code]...
When i am pressing any key in the textbox it will return "A" Character.[code]...
View 2 RepliesI've been searching for the answer for this all over, but I can't seem to find the solution. I have no idea how do this. A code that triggers an event after multiple command buttons are pressed in a certain order. For example: I press Command1, then Command2, then Command8, then Command5, then an event happens. It's kind of similar to entering a code to activate something.
View 4 RepliesI have the following problem with MEF: Interface definition to be used by host:
Public Interface IExecuteDoSomething
Inherits IAddinSettings
Event DataReceived As EventHandler(Of DataReceivedEventArgs)
Function DoSomething() As Boolean
End Interface
[Code]...
Everything seems to work fine until the Button2_Click routine is executed, then an InvalidCastException is thrown with the info:Unable to cast object of type 'System.Collections.Generic.List1[SharedLibrary.IExecuteDoSomething]' to type 'System.Collections.Generic.List1[SharedLibrary.IAddinSettings]'.
How can i solve this problem, because the imported object implements both of the interfaces?
In this discussion let us discuss every usage of interfaces in .NET. Any real time examples and difficulties in using interfaces can also be discussed here.
View 6 RepliesHas someone a hint what I'm doing wrong in VB.Net?
Module Module1
Interface ISearch(Of T As ISearchResult)
Function ids() As List(Of T)
End Interface
[CODE]...
The third cast isn't working. Why? did I miss a oop lesson?