Performance impact on use of this/me keyword

Windows Forms General

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    - Detect Computer Restart Is there any way to detect whether this is the first time an application is running since the user has logged on to Windows There is a bit of functionality that I would like to reset whenever the computer is rebooted or the user logs out and logs back in and I would appreciate any information on how to detect this Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Object not being Garbage Collected, why? It appears that I have some kind of memory leak in my code (to a degree). I have an object that maintains unmanaged resources, this object has an init() and deinit() member function for allocating and deallocating those unmanaged resources. These resources are used to create a managed Bitmap. When allocated, the object takes about 8mb of RAM, so it's pretty obvious if it doesn't deallocate at some point. Anyways, I've thrown together a couple lines of code to test and make sure all is going well, and this is my results: Code Block GC::Collect(); //Clearing memory before everything (~31mb used) myObject->init(); //Uses ~8mb //myPicturebox->Image = myObject->bmp; //Commented out for this example //myPicturebox->Image = nullptr; //Commented out for this example myObject->deinit(); //Clears ~8mb GC::Collect(); //Clearing memory after everything (~31mb used) This works fine- as you can see from my comments, the object init/deinits fine. The problem is if I uncomment those 2 lines of code, all they do is assign my created Bitmap to a picturebox, then unassign it again. But after Garbage Collecting when I've done that, my 8mb in my object isn't cleanup up anymore! (Which leads me to believe that somewhere in assigning my Bitmap to the picturebox, .NET keeps another reference to it somewhere, so it won't be GC'd... Code Block GC::Collect(); //Clearing memory before everything (~31mb used) myObject->init(); //Uses ~8mb myPicturebox->Image = myObject->bmp; //Assign to picturebox myPicturebox->Image = nullptr; //Remove from picturebox myObject->deinit(); //Doesn't clear ~8mb anymore! GC::Collect(); //Clearing memory after everything (~39mb used) My original test code had GC::Collect() calls between every line, so I could monitor exactly where RAM is allocated/freed, but I left them out for simplicity's sake in my examples. Any thoughts Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - How to add a child node to a TreeView using an index? Hi, Suppose I have 10 TreeView parent nodes and I want to add child nodes to them by index, like first 3rd node and then 2nd, etc. Anyone knows how is it done Thanks, aw Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Arrow Keys don't move controls in custom forms designer Hello, I have a custom forms designer. I've implemented a menu command service like so MenuCommandServiceImpl mcsi = new MenuCommandServiceImpl (); host.AddService( typeof ( IMenuCommandService ), mcsi); MenuCommandServiceImpl is derived from IMenuCommandService. I "think" that the controls are supposed to move when the arrow keys are pressed via the MenuCommands .KeyMoveUp etc. Commands. I've added those commands to my MenuCommand class, but nothing. In all my searching around, I think that the DesignSurface.View is stealing the key press events for the Arrow keys, and should be the one to fire the correct events or preferably move the controls. Have I added the wrong service or is it possibly added in the wrong order or is there somewhere else I need to look. Ken Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - movement of ovals Is there any way that i can move one oval so that its location(x,y) coordinates can follow the path of another oval's border The result would be an oval moving around another oval Thanks in advance!! Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Label auto height I'm building a custom messagebox. All works fine, but I thing not.... I want my messagebox auto resizes in height when adding more text than expected in design mode. In design mode a draw a label of 4 lines of text, but when I call the new messagebox with much more text, it disappears. The call of the messagebox may have 10 lines of text, without any "environment.newline". So, in that case the messagebox AND the label have to resize in height (not in width!). Optionaly the OK/Cancel button have to replace, to position themselfs again under the resized label. Is this possible Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - panel.hide/show vs. panel.visible What is the difference between using panel.hide, panel.show or panel.visible = true/false. Can't find this info anywhere. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Datagridviewcolumn with ComboBox and TextBox cells together Hi, I am trying to mix some ComboBox cells and TextBox cells together in DataGridViewColumn. But I don't have succeeded. Is this even possible Also, if I am trying to modify dynamically Datagridview it throws an exception: "Collection already belongs to a DataGridView control. This operation is no longer valid." Codeline is following when using C#: this.Rows[2].Cells.RemoveAt(index); Thanks forehand for answering. T. Juni Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Resizing the RichTextBox when paste the content Hi Members, I have developed the user control .Net windows application. the control has a panel with some set of RichTextBox even height and even width. The cotrol also has a ToolStripBar with Bold, Italic, Font list, Font size list. When the user type any content with any RichTextBox it will get resize according to the content size in vetically and also the other RichTextBox relocated accordingly inside the Panel. The panel also make it visible by the verticalScrollBar. The user can change the font information alignments by the ToolStripBar I have maintain the those information seperatily in ArrayList. when RichTextBox get focus the corresponding information featch from that ArrayList. when the RichTextBox get resize these information will consider for height calculations. My problem is I can't get exact height when paste some content inside the RichTextBox with regards, Vimal Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Datagridview overwriting all rows if populated unfocussed! Hi, I have a tab control with 2 tab pages. Both pages have a datagridview on and show similar information. I initially populate them with by using a bindingsource (bound to a binding list of custom objects). I then scan the bindingsource and dynamically create multiple unbound columns and populate the relevant cells. This works fine for the first (displayed) tab but not the second. If the first tab is displayed when the datagridview is populated the second DGV's unbound columns show null values. This doesn't happen the opposite way round (the unbound columns populate ok). I created a collection of datagridviewcells so that i could monitor the cells to see when they were being changed back to null. Turns out they're not being changed, infact, all of the rows are being replaced with new rows! I'm guessing this has something to do with the databinding and focus of the DGV but i can't detect any events happening when i activate the second tab with the DGV on! Any help much appreciated! ** Forgot to mention - if i reload the data while the program's still running it works fine! But i don;t think the users would appreciate me telling them it's a 'feature' for them to have to click the button twice! Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Database Project Setup Hello, I am having troubles understanding the dynamics of publishing or creating a setup for a database project. I have a VB Windows forms database application which contains a database in it. I am using it in my development environment with no problems. However, when I publich it using click once or adding a setup application, I can never get the application to work correctly in the target machine. It seems that the application can't find the MDF file or attach the database. What is the best scenario in this situation Thanks PS: My connection strings includes the "AttachDbFilename" directive. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Sending Fax Hi fellows, I am just curious to know if there is any .NET classes that can be used to send fax from a windows application. Thank you. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Enabling/disabling datagridview depending on datasource values Hello to everybody My problem is that I have a datatable with 1 bit (or boolean) field and this table is datasource of the datagridview. I want to disable few cell in datagridview depending on value of this field. I can make invisible column in datagridview bound to this field and check all rows in datagridview but I think there are better ways to achieve this. Any suggestions Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Getting selected index from ListView I need to get the index of a selected item in at ListView. This is for a single-select ListView. I understand how to get the collection of selected items but since that doesn't be 0 good, I was hoping there was a way to get the index into the ListView so I could directly reference row items... How is this done D Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - How to scroll controls in a custom control i.e. s there a way to change the position of the child control on scrolling? I am developing a custom control which would act as a PDF viewer. I am extending this control from the Panel control(Please note i have enabled double buffering of controls). I am not using the auto scroll property i.e. i am manually controlling the scrolling. The control works fine if there are no controls. But when there are controls in it i have to change the poistion of the controls in the paint event. Now the problem is that the whole re-painting occurs of those added controls. Is there a way to change the position of the child control on scrolling Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - How to implement copy/paste/cut/undo/redo commands in C#? Could someone please tell me how to implement the copy/paste/cut commands for the Edit menu items in C# 2005 I can implement those commandsfor each textbox individually, but my application has about 100 textboxes. It will be very tedious to do the same thing for each of them. I guess there must be some way to implement those commands for the whole application. Thanks! Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Custom Folder I need to create folder in every user folder when i setup my application on other machines Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Modal Form Hi all, I need to show a form as dialog to a parent window only not modal to the entire application. see if i have three forms form1, form2, form3 first i showed form3, then form1 and set form2 as modaldialog from form1 , now i cannot access form3 also without closing form2, ie form2 is modal to the entire application Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Why to double click SQL DB File for connecting. Hi, I have added a SQL Database in my Visual Studio 2005 (C#) project. I am accessing it with AttachDbFilename=|DataDirectory|........... and it is working fine as I can access the database when i run the application. But the problem occurs when i close the project and reopen it in new visual studio instance and starts debugging, it gives exception as it doesnot connect to database. Then i double click the already added SQL Server DB file being shown in my solution explorer and again start debugging then it works fine and easily connects to DB. Another thing which I experieced is that when i open the new instance of visual studio for above mentioned task. Then my SQL Server DB is not shown in Server Explorer under current connections. But when i double click my SQL Server DB in solution explorer then it start showning that DB in current connections. Environment : Visual Studio 2005 SQL Server 2005 Express Edition Windows XP SP2 Thanks Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Web browser problem Hi, I am creating a simple htm file on disk that points to a particular flash file (swf). But when I point the url of the web browser to this file, it loads but the place where the swf file should show up, only shows the square X mark, meaning the file couldn't be found or be displayed. When I run the file in windows by double clicking, it asks me if I trust the file (using the information bar), and when I say Allow Blocked content, it shows the swf. Is there a way to turn this off, or work around this I am not even sure if this is the problem. Because I see various software that does this, like wink. It opens an htm file showing a particular swf. Thanks alot, aw Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Assigning icon from default settings on target machine I am using VS 2005 to create a setup project for my application. I have added a shortcut in the user's Start menu for the supporting documentation for the application, which is a PDF document (stored in the user's Application Folder in Program Files). I want the shortcut to use the default icon on the target machine for PDFs (they might be using Adobe Acrobat, PDFComplete, not have a PDF viewer, etc etc). Is there any way to do this I know how to assign an icon that I include in the setup project (I've done this for the shortcut to the application .exe), but I don't want to make any assumptions about the type of PDF viewer installed on the target machine, so I'd rather pick up an icon from their default settings. Thanks Claire Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Textbox value lost while validating Hi, I am having a problem implementing databinding in my .NET 2.0 app. I have a number of controls on a user control (the user control's autovalidate property is set to 'disabled'. I fill in the form fields, and try to save the data. The application calls ValidateChildren() on the user control, and my Validating event handlers fire as expected. But somewhere during this process (while the validating event handlers are running) one of my textboxes loses its value (it's reset to empty string). So, by the time its own validating event handler runs, it fails because this is a required field. The really odd thing is that if I then try to save this again, everything runs as expected. This is a sample of the code that adds the databindings to my controls: Code Snippet private void CreateControlDataBindings(customBusinessObject b) { this._personBindingSource = new BindingSource(); this._personBindingSource.DataSource = b; this.cboTitles.DataBindings.Clear(); this.cboTitles.DataBindings.Add(new Binding("SelectedValue", this._personBindingSource, "Title", true, DataSourceUpdateMode.OnValidation)); this.txtForename.DataBindings.Clear(); this.txtForename.DataBindings.Add(new Binding("Text", this._personBindingSource, "Forename", true, DataSourceUpdateMode.OnValidation)); //this is thw one which loses its value this.txtSurname.DataBindings.Clear(); this.txtSurname.DataBindings.Add(new Binding("Text", this._personBindingSource, "Surname", true, DataSourceUpdateMode.OnValidation)); } And these are my validating event handlers: Code Snippet private void cboTitles_Validating(object sender, CancelEventArgs e) { e.Cancel = !this._validationManager.ValidateItemSelected(this.cboTitles, "A title is required."); } private void txtForename_Validating(object sender, CancelEventArgs e) { e.Cancel = !this._validationManager.ValidateNullOrEmpty(this.txtForename, "A forename is required."); } private void txtSurname_Validating(object sender, CancelEventArgs e) { e.Cancel = !this._validationManager.ValidateNullOrEmpty(this.txtSurname, "A surname is required."); } The first two both run as expected (i.e. they don't cancel the event), then somewhere between the 2nd and 3rd handler, the txtSurname text value is reset. I notice a slight pause in the application before this happens- almost as if the application is trying to push some data back to the datasource, and failing for some reason. The business object I am working with contains both a Forename and Surname property, so the problem is not that it can't write the value back to the property I have bound the control to. If anyone has any suggestions for how to make this work, I would extremely pleased to hear them, as informing the prospective users that they will have to click the save button twice would not go down terribly well. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - DataGridView, CheckBox fields and Strongly Typed datasets.... I have run into a particularly irritating problem and I am hoping that there is a simple solution. I have a couple of DataGridViews on tabs in a tab control. The DataGridViews have a mix of Check boxes and text cells in them. The Datasources are pointing to tables in a strongly typed dataset. In one case I have a non-Databound column ( a check box ) and in the other grid all fields are databound. The problem that I am seeing is that my column ordering is not staying the way I put it. Something that either I or VS 2005 is doing is putting all the checkbox fields at the very front ( far left ) of the datagrid. This gets very frustrating as it happens on the grids regardless of whether or not I happen to be actively working on them in VS. More importantly though there is the strong possibility that I will yet again get my columns reordered for me just prior to a release and the client will get it that way. Anyone have any clue why this may be happening Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Find a window control at a point on the screen How do I find a control (such as a text box) from a window running in a separate process based on an X,Y screen coordinate Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - MaskedTextbox and allowing only valid int input I��m trying to setup a MaskedTextbox on a form to allow for only valid int input, but can��t seem to get something that I��m happy with. What I need is that the user enter something that��s entirely numeric (no decimals or negative signs), a minimum of 1 digit and a max of 4 digits. I��ve set the following properties: Mask=��0000��; ResetOnSpace=false; TextMaskFormat=MaskFormat.ExcludePromptAndLiterals;, and if you type in ��323_��, or ��_323��, its fine, and it doesn��t allow the user to press space. But, if you clear the field and type 3 (right cursor over) 23 to produce ��3_23��, it obviously does not parse as a valid int. I then decided to try setting the maskedTextbox1.ValidationType = typeof(int); and setting up a typeValidationCompleted event, but unless the whole mask is completed (4 digits), it fails. How can I get this to work in my favor Its almost to the point that I just roll my own based on the standard textbox. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - CheckedListBox DataSource property Hello As mentioned in the documentation, it is not recomanded to used the DataSouce, DisplayMember and ValueMember properties. Does anyone have an idea why Thanks, Gil Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - DataGridView Scrollbar Hi, I have a datagridview control on a form that contains lots of rows populated from an SQL database (done in code in a grid refresh subroutine). I have a timer control that updates the grid every 10 secs. The problem I have is that if I am in the process of scrolling down the grid and the timer event fires off a grid refresh, the grid resets the grid location and scrollbars. What I want to be able to do is set a flag on a mousedown event of the scrollbar and more importantly reset the flag on the mouseup event. This will enable the grid refresh routine to decide whether to refresh or not. However I don't seem to be able to do this as the events do not exist. The Scroll event allows me to set the flag to disable the refresh but I don't seem to be able to find a similar event to allow me to enable the refresh again. Can anyone help I am using VB2005.net Cheers Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Parent, child forms check if open or closed Hi all, I'm new to c# and currently working on a project containing mdi forms. This is how the project is layed out. Parent form is called Street_Index. This contians a menu strip which can open 2 different forms. * Street_Search * Office_Search Within the Street_search form there is a button that i click that returns the results in another form called Search_Results. Search Results contains a grid and on double clicking the column of the grid it returns the results of that row back to Street_Search form which displays them in textboxes, grid, combobox, etc.. Within the Office_Search form there is also a button that opens the Search_Results form and then from there you can double click on the grid within Search_Results and open up Street_Search form which will display the results as previous. Now onto the question. What is the cleanest possible way to check to see if a childform is open or not and if it is refresh it or bring it into focus Thanks in advance Take care all. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Suddenly I'm getting this error: The form referred to itself during construction from a default instance Hi, I'm getting the error below when I try to run my project. It's never happened before, and I don't understand what's caused it. Can anyone help please Thanks, Louise System.InvalidOperationException was unhandled Message="An error occurred creating the form. See Exception.InnerException for details. The error is: The form referred to itself during construction from a default instance, which led to infinite recursion. Within the Form's constructor refer to the form using 'Me.'" Source="FrontierIS" StackTrace: at FrontierIS.My.MyProject.MyForms.Create__Instance__[T](T Instance) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 190 at FrontierIS.My.MyProject.MyForms.get_frmData() at FrontierIS.My.MyApplication.OnCreateMainForm() in D:\contacts\FrontierIS\My Project\Application.Designer.vb:line 35 at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine) at FrontierIS.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81 at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - datagridview - testing values of an unbound column Hi there. I have a datagridview that I populate via a table adapter and everything is working just fine. Now i'd like to give the user the option of: selecting multiple records in the grid by checking a checkbox. this checkbox is available for each row of data and i created it by adding an unbound column. What i'd like to do is enable a button on the same form only if one or more records have been selected by the user. how do i do this I was thinking about using the event: Private Sub DataGridView1_CellContentClick( ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick End Sub but this event can potentially be fired many times and for any column that's selected. Any suggestions Also, what's the easiest way to allow the user to edit the data for a given record I need to do another query when they request an edit because the current datagrid doesn't show all the details for the record. I intend to launch a new window to do this. Please and thanks. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - how to host different controls in the same column in DataGridView control Hi, I am trying to create a datagridview. And in one column i want to have different type of cells (hosting different editing controls). For example, in the same column first cell shall host a combo box control, second cell shall host a text box control, third cell shall host DateTime picker control, another with Colorpicker control, etc. if i follow the host controls in windows forms Datagridview cell and c urrently if i change the cellTemplate property of DataGridViewColumn to calendarcell, then all the cells in that column become calendar cell. But instead i want to have a different control, for example colorpicker, in the next cell ie the one below this. Please advise how to achieve this using datagridview cell. -Madhu. Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms
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    - Removing multiple items in a ListView "at the same time" Hi all, Suppose we have 5 items in the ListView: "Alpha", "Bravo", "Charlie", "Delta" and "Echo". When we execute RemoveAt(0) followed by another RemoveAt(0), the first two items got removed. If we execute RemoveAt(0) followed by RemoveAt(1), "Alpha" and "Charlie" got removed. What I want to achieve is: I can multi-select items in the ListView to decide which items i'd like to delete. For example, I select "Alpha" and "Delta", so the index 0 and 3 are stored in SelectedIndexCollection. Then I enumerate this collection to delete these two in one run. At this time, if I run RemoveAt(0) first, the index of "Delta" will be changed to 2. Can I delete multiple items "at the same time" in the collection without having to mess with the indices Tag: Windows Forms General Performance impact on use of this/me keyword Windows Forms

augustus

The this/me keyword isn't required in many circumstances. Is there a performance advantage or disadvantage to using it when it's not required

Gus

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Re: Windows Forms General Performance impact on use of this/me keyword

Mike Danes

No, it does not affect the performance in any way. Basically if you don't specify this/me the compiler will "autogenerate" it anyway.

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