Dim x as whatever
Try
x = new whatever(1)
something is done with x
[code]....
What happens to x = whatever(1)Does garbage collection find the pointer to the first new and destroy it or what?
If I use a single variable of type Excel.Worksheet to reference Worksheet1, and then change it to Worksheet2, Worksheet3 and so on, is it adequate to simply do "Marshal.FinalReleaseComObject(worksheetVariable)" once at the end? Or would I be left with some references still in memory? In other words, do I need to do a "Marshal.FinalReleaseComObject" before each re-assignment?
View 3 RepliesI have prided myself in having a pretty clean code however in the game I am making I have a player view (showscreen) and a host view, which is a copy of the player view (on a smaller screen). This way the host can see what's going on.The problem is that the graphic doesn't dispose properly and Garbage Collector gets it, though I have noticed it will crash if GC doesn't get it in time. The larger the showscreen window the more junk gets put into memory, which sucks.I thought I had everything correctly disposed below but still doesn't get the job done.
[code]...
I thought that when a variable went out of scope (like a variable declared within a method - when you exit that method the variable is out of scope) then it was eligible for garbage collection and when it was garage collected the Dispose method is called on it. Now I know that it does not get disposed immediately but I assumed it would be basically as soon as the process starts to take up quite a bit of memory.However, I found that my app's memory usage seems to constantly increase when I dont manually Dispose of a specific method local variable. Of course its good practice to call Dispose and ordinarily I would but I just didn't realise that this particular class actually implemented IDisposable. The class in question was the System.DirectoryServices.SearchResultCollection class, and I was looping through the items in it like so:
[Code]...
I'm creating a windows forms program and have recently noticed a large amount of memory slowly being eaten by the application. I went through my program and tried to tie up as many loose ends as I could in relation to object creation but noticed that the program would still keep memory for every form loaded until it eventually crashed.
I decided to make a simple test program which sole purpose is to pop-up a new form with a few controls, wait for 200 milliseconds, then close the form and repeat the process 30 times every time I hit a button. I found it caused the same behavior, even with the only new object creation being that of the form. So, I decided to manually invoke the garbage collector in a subroutine which handles the formclosed event. During tests I would get some memory back occasionally, but not enough to make a difference in the long run. So I start setting the form variable to nothing before I called GC.collect(). The program will initially eat a few 1000K of memory before leveling off and using only 20-40K for every 30 forms created.
Now what I'm wondering is, what is the point of an automated garbage collection system if it requires constant manual evocation and explicit dereferencing of all new objects to be effective? Have I completely lost grasp on the scope of VB.Net forms and it simply never marks forms as available memory to be cleared?I would have thought object memory references created within a form would be marked as usable when the form's close or dispose routine is called and no references to objects created within the form exist anywhere outside the closed form.
I am trying to create radiobuttons, and then create code for them after they are created. I have the code to create the radiobuttons. What I want to do is create a sub for the event of changing the check value for the radiobutton. Or to have the check value recognized by a button click. For example, you click the button and if the first radiobutton has the circle filled then a msgbox comes up and says hurray. My code so far is this:
View 6 RepliesI am using a function from a dll in unmanaged code that requires a callback to my managed code in Visual Basic 2010. The callback is asynchronous and is called continuously over the life of the application. What's the best way to protect the callback function from the garbage collector? Right now it is being collected after several dozen calls from the dll.
View 11 RepliesI've been doing some reading on garbage collection in .NET and I was hoping for some clarification. So, as I understand it if I declare a public shared class variable, the GC will never get rid of it. Is this correct?Also, what then of private variables? Take the following example:
public class myClass
private shared myString As String
public sub ChangeString(newString As String)
[code].....
I have a callback function in a C+ dll:
<UnmanagedFunctionPointer(CallingConvention.Cdecl)> _
Public Delegate Sub DeviceDetectionEvent(ByVal YasdiEvent As YASDIDetectionSub, ByVal DeviceHandle As UInteger, ByVal param1 As UInteger)
[code].....
Is the memory from primitive data types (int, char,etc) immediately released once they leave scope, or added to garbage collection for later release?
consider:
For x as integer=0 to 1000
dim y as integer
Next
If this doesn't add 1000 integers to the garbage collector for clean up later,how does it treat string objects? would this create 1000 strings to clean up later?
For x as integer=0 to 1000
dim y as string=""
Next
How about structures that contain only int,string,etc... data types?
Datatable object within class function + garbage collection?
View 3 RepliesHere's the scenario, winforms application, monitoring via Task Manager Processes Tab.On initial launch spins up to ~61,000K (initial data grid and data loads)If I minimize the application, not touching or doing anything the Mem usage drops to 1,380K.When I restore the application is spins back up to only 5.8K
So my question is, does the minimize send some internal message to clean up resources since the application in question is not in focus?The first app I noticed this in happens to be VB.NET, but I've observed the same behavior in my main C# winform applications.
I have a theory that the CLR garbage collection mechanism means that I can get away with circular references in my object hierarchy without creating deadlocks for teardown and garbage collection. Is this a safe assumption to make? (Target language VB.NET)
View 2 RepliesHow to dispose the shared variable in vb.net.i am using shared object of Asterisk.NET Manager Variable, i assigned it in form load and i dispose it in main form closing, My problem is after closing the application, application.exe keeps live in task manager, if i not initializing the shared object in form load there is no problem,[code]
View 3 RepliesI have 2 question, hope somebody give me an explanation: 1. Should a local variable call dispose method and set to nothing? 2. If some method have an arguments which it is a ByVal argument, it means a method create a new object? But If it is a ByRef argument, it means a method don't create a new object?
View 4 RepliesI am trying a example codes of animated graphics. I rewrote all the code and I found an error which doesn't happen on the example code(I run the example project)
error: 'Protected Overrides Sub Dispose(disposing As Boolean)' has multiple definitions with identical signatures.
when I double clicked the error, I got this in Form1.Designer.vb:
'Form overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()> _
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
[Code]....
I looked at the Dispose() method in System.Data.SqlClient.SqlTransaction (using a decompiler):
[Code]....
Why does everyone say in forums that it is Rolling back in the dispose? Where does it rollback?
I want to define a variable that is a collection of interfaces - it could be any interface that is defined for use in my app.
e.g. Dim x as New List(Of InterfaceBase)
Is there a base type for all interfaces that I can use for InterfaceBase?
I'm trying to create a collection of variable binding in a class.It is intended to look something like this:
Dim x as integer, s as string
Dim c as new VBindClass
x = 1
s = "Hello"
[code]....
Is there some function that allow us to retrieve a unique ID for a given variable and also get/set based on variable?
Update:At last, I've managed to found the answer. Here's the code:
Dim gh As Runtime.InteropServices.GCHandle = Runtime.InteropServices.GCHandle.Alloc(obj)
Return Runtime.InteropServices.GCHandle.ToIntPtr(gh).ToInt64
I want to create a collection with multiple properties.
View 15 RepliesDo you know how to declare a variable that can hold the result of a call to GetFiles?
I don't know how to do this, so I am using the following verbose/duplicative version:
Dim l_v_String_FoundFile As String
If My.Computer.FileSystem.GetFiles("A:u_Au_W", FileIO.SearchOption.SearchAllSubDirectories,
[code].....
Do you know how to declare a variable that can hold the result of a call to GetFiles?
I don't know how to do this, so I am using the following verbose/duplicative version:
Dim l_v_String_FoundFile As String
If My.Computer.FileSystem.GetFiles("A:u_Au_W", FileIO.SearchOption.SearchAllSubDirectories, l_v_String_FileMask).Count = 1 Then
[Code].....
While working with an excel file (.xlsx), the data I get from it is an IEnumerable(of Dictionary). When I bind this to my datagrid, I get the problem that I only see 2 columnsI've been tracing this problem and discovered that in the first row in the excel, there are only 2 values (cell C and D). I think the binding to datagrid looks at this first row to create its headers. This results in my datagrid only showing columns C and D.
View 1 RepliesI have two combo boxesthat use the same collection for their datasource. The data member and value member are also the same properties. When the form loads, and I select an item in one of the combo boxes, the same item is then selected in the other combo box. I want the combo boxes to work separately. Do I need to have two different collections, even though they would have the same data in them?
cboInboardKnife.DataSource = cKnives
cboInboardKnife.DisplayMember =
"Name"
cboInboardKnife.ValueMember =
"ToolID"
cboOutboardKnife.DataSource = cKnives
cboOutboardKnife.DisplayMember =
"Name"
cboOutboardKnife.ValueMember =
"ToolID"
I'm still teaching myself how to bind and use observable collection. One problem that I'm a little confused on is binding multiple classes/observable collection to one page. In other words, if I have a PersonName class and a AnimalName class, I have to create two separate observalbe collections for each? How would I set the datacontext when a page only allows one?
[code]...
Now If I add another class, how would I combine the two on the binding part and collection part.
I've been working on this problem for a while and I'm clearly missing something...I create, populate and bind an observable collection like so:
Dim _ObservableWEI As New ObservableWEI
...
_ObservableWEI.Add(New WEI() With {.WEInum = 1, .WEIvalue = 1})[code].....
The problem is the filter effects the contents of both listboxes. I guess I need a specific instance of the collection to apply the filter too or something
On my view there is a datatable holding a collection of ServerRow and 4 textboxes (Hostname, OS, Location, Zone). When the user types into any of the 4 boxes I want to immediately filter this list. I have this code setup and ready to go that on the set method of each textbox property I call the filter method.
Now onto the problem: if I have 4 criteria that means I have 2 to the power of 4 different scenarios. What I would like to do is write a linq statement with all of these scenarios dealt with such that if any of the properties are NullOrEmpty they will not be used in the Where clause and on the flip side if there is a value the corresponding field will be searched with a Contains.
Example
AvailableCis = New ObservableCollection(Of ServerRow)
(_CiData.Where(Function(ci) ci.OS.ToUpper
.Equals(_selectedOS.ToUpper) AndAlso
ci.HostName.ToUpper.Contains(_ciNameFilterText.ToUpper))
.OrderBy(Function(a) a.CiName))
This example shows how it works with 2 criteria and both of those criteria are set.
i have the following snippet of
For Each tempstring In SourceDataCollection
LineToFieldsTemp = Split(tempstring, ",")
LineStringWithoutFirstEntry = "" 'reset the linestring
For i = 1 To UBound(LineToFieldsTemp)
[code]....
essentially what i'm doing is to read through each item in a collection of comma separated variable strings. the first variable in each string is appended to a master filename and becomes the NEW filename to which the entire string will be appended. this is a way to split a CSV file into multiple files using the first variable in that string.
the trouble is that this is doing a LOT of writes to potentially a LOT of files, the IO is taking forever. is there a way to buffer this data until the end, then write it to a disk? be aware, the filenames and total number of files to be created is UNKNOWN at the begining of the loop. it just creates a new file each time a unique first column ID is discovered.
other than GML (Yoyogames.com Game Maker Language), I am new to the coding world. The only "major" project I have completed using VB is a computer calculator that exactly mimics the capabilities of Windows 7's calculator. Yesterday, I began a Chatbot program for my girlfriend. Lol. I have used the instr() function to answer most of the questions or answers which are typed into the textbox1. I find this extremely troublesome because when using the instr() function you cannot say instr(textbox1.
Public Class Form1
Dim fos As String = "Foster: "
Dim ash As String = "Ashley: "
[code].....
I am considering a piece of code that will manage access to a collection object from multiple threads - add, update, remove, clear. OK ... so I have put a sync lock within each method, but what is not clear from the MS documentation is exactly how the sync lock is behaving. Is it locking the piece of code it wraps? Or is it locking the object? And if it is locking the object a private static object should lock out any code locked on the object within all instances of the object? i.e. if an add operation is underway, an update, delete or clear will wait for the lock to be released.
Finally, if I have multiple threads contending for the sync lock, how is the release managed? First come, first serve? random (from my p.o.v)? Is there a chance that two separate threads could blunder into 'locked' code simulataneously?