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 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:
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:
I 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.
I'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)
<UnmanagedFunctionPointer(CallingConvention.Cdecl)> _ Public Delegate Sub DeviceDetectionEvent(ByVal YasdiEvent As YASDIDetectionSub, ByVal DeviceHandle As UInteger, ByVal param1 As UInteger)
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?
Here'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.
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?
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)
My program shows some browser. From a browser user can open maximized MDI form with some report. When user is closing the report, first MDI form with browser is became maximized.
2 forms have same MDI parent. Can I change this behavior to leave my first browser form without maximizing after second report closed?
VB6 application MDI-Child architecture. Closing event is handled via QueryUnload event in both MDI and child form. Order of event trigger is MDI form closing(QueryUnload) event fires first followed by child form closing event(QueryUnload, I would like to call it as FormClosing itself as it is more comfortable and correct)Now after migration, order of event trigger is occuring in reverse. Child form closing event is firing first followed by MDI form closing event. We want to reverse the event triggering badly because of the logic written inside the closing events. Swapping the logic inside the events is not a viable option considering the huge changes we need to make (we have 31 vbprojects with 31 MDI forms and numerous child forms).
How I can make the MDI's closing event to be triggered first before child's closing event?
Ok I have a project which has a MDI parent. Inside the parent I have multiple isntances of a form load(frmLine1t5). When my program loads it will load a different form(frmSelect) and if I manually load a different form(frmRetests) I can put frmSelect on top of frmRetests and bring one another to the front if it's clicked on(without using the bringtofront method)However as soon as I load a single instance of frmLine1t5 I immediately can no longer bring ANY form loaded into the MDI parent(before or after frmLine1t5 has loaded) to the front. I can only bring them to print IF I use .bringtofront method
I've heard that the c# garbage collector can be 'more aggressive' than it's vb.net counterpart. Is this true? Are there any other differences in how garbage collection is run in vb.net vs. c#?
I'm trying to introduce delay to my code so that it would read in the noise or garbage data. I'm receiving the data from RFID to pic thru RS232.Is there any simple delay that i can use? I seriously don't understand threading.
If I want to narrow scope of a variable in C#, I can introduce additional braces - i.e.:
class Program { static void Main(string[] args)[code].....
In the ide, I can no longer reference y outside of the scope introduced by the new braces. I would have thought that this would mean that the variable y would be available for garbage collection.(it is interesting to note that when viewing the compiled code using reflector it appears that there is no difference with or without the additional braces)Is there any way similar to this to narrow scope when using VB.net? Does this have any impact on when variables defined in the inner scope may be garbage collected?
with VB.NET + MySQL i am having a connection object which is public public MYcnn as MySql.Data.MySqlClient.MySqlConnection when my main form opens MYcnn will open & will be available for all the procedures & functions. i never close this connection until the last form of the application closes (yes of course i compromise of some security + performance issues)
my problems is(1)when & how the garbage collector works to collect my connection object if my connection object remains open for > then certain time(2) how to offer or fix the time of my connection object availableness to garbage collector (3) i would like to write an event for the connection object closed event(i am explicitly declaring the connection object)
I have an Excel file that downloads automatically, but for some reason the binary XLS file contains some garbage HTML text at the end of it.
When opening the file in the Excel application, it shows a warning but proceeding will automatically remove the garbage HTML text.
However, I need to open the file programmatically. When doing so via
Dim wb As Workbook = Excel.Workbooks.Open(ExcelFileName)
It throws:
Exception from HRESULT: 0x800A03EC
a) Get Excel to perform a similar action as if I manually opened it and remove the garbage HTML automatically. NOTE: Tried setting the XlCorruptLoad.xlRepairFile parameter and it didn't work.
OR b) Remove the garbage text from the XLS binary file (FileStream?) and resave it before attempting to open the file with the code mentioned above.
The garbage html always comes at the very end of the file and starts with
Public Function AddNewButton() As System.Windows.Forms.Button ' Create a new instance of the Button class. Dim aButton As New System.Windows.Forms.Button()
I am wanting to make a collection of form instances.I was wondering if the arrayList is a list of pointers (or references) to items added or if a new instance of an object is placed when using the add method.
i.e. if I had: Public Shared forms as Arraylist = new Arraylist Then if I called forms.add me from an instance of a form would it create a pointer or reference to the instance or generate a whole new one?
I have 5 text boxes that I need to perform several operations on as a group, named tb1, tb2, tb3, tb4, tb5.for example, if I want to retrieve the text from each one and process it, I believe I can use the text box or control collection and test each textbox to see if it's name starts with tb, check to see if it has text in it, and then process the text.I think I would use something like for each textbox in..... to test the collection but not yet comfortable with collections and this seems like a good place to start learning how to use them.
I have a problem with an application, in this case I have a windows services. its function is generate reports depending of demand of our users.In some cases the memory usage of my windows services is to 2 gb of RAM. I disposed all objects that my application use . but the memory usage doesn't low.I tried to reduce the memory usage forcing to garbage collector to Collect with the method "GC.Collect"but it's not recommend because uses many time of CPU.Surfing on the internet I found a method named "SetProcessWorkingSetSize" that free memory usage correctly. http:[url]....but some cases my windows services named sapdkadm_procesoestandarejecucion.exe has some error message in event viewer is the next:
Faulting application sapdkadm_procesoestandarejecucion.exe, version 1.0.0.0, stamp 4f908fef, faulting module kernel32.dll, version 5.2.3790.4480, stamp 49c51cdd, debug? 0, fault address 0x0000000000027ded.
The real problem is that when this happens my windows services restart
Is it good practice to store sub-collections of item X inside a parent collection of item X for caching 'filter-queries' which are performed on the parent collection? (They won't be used together (as in color AND type).) Or is it also ok to just Loop over the collection and return the correct entities in a temporary collection?
