I have a DataGridView where I bind a datasource (sql query) to it. The row count is high with many columns. Trying to scroll through this DGV is painfully slow.
Does anyone know of any kinds of optimization I can do so that I can scroll faster? Like what is the DataGrid doing when you scroll? Does it repaint every screenful? Does it validate every row? It seems like it is doing something unneeded when a user scrolls.
i need to scroll a datagridview, my scroll bar is set to false so i need to do it using code.currently i am scrolling using the following code, but i would like to modify the code to scroll from one line to the next and see the blue bar actually selecting the rows. how do i do so
Private Sub grdMouseWheel(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
[code].....
I have around 100 items in a menustrip like your favourites menu in internet explorer. Is it possible to scroll down using the mouse scroll wheel?Is it possible to automatically scroll when the mouse pointer is over the arrow at the bottom or top as opposed to having to click to scroll the menu?
View 2 RepliesI have a DataGridView with, say, a half dozen columns on it; the right-most column being the widest (a description that might exceed the window's width). If the user presses the Home/End or PgUp/PgDn keys to navigate thru the data, it will sometimes scroll horizontally to the right, which is annoying. Is there a way to prevent this?
I've tried .ScrollBars = ScrollBars.Vertical(so there's no horiz scrollbar), but that doesn't solve the problem. I'm not sure how to make the 1st column be always visible - but even if I make it visible upon displaying the grid.I guess basically I don't WANT it to scroll horizontally, except when the USER scrolls.
I have some data in my DataGridView. I want the user to be able to scroll through data but not select any item. If I make enabled=false, even scrolling does not work
View 2 RepliesI have the following Code in my Form, but the PrintPreviewDialog is not showing all rows. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
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i created a datagridview whcih i am populating from a DB table.unfortunately i had to cancel the scroll bar's and lost the ability to scroll down using the mouse wheel.i was able to create a new handler to handle mouse wheel Under the form load event [code]but i still can't scroll down, and i am a bit lost.
View 4 RepliesIs there a way to use wheel mouse and scroll vertical bar without actually get focus on datagridview in vb.net?
View 1 RepliesHow (if possible) can the datagridview be set to not scroll to the last row when adding a new row?
View 1 RepliesI have 2 datagrids and I want one datagrid to have a scrolling bar and the other should not have a scroll bar. How can I track the on click event on the scroll bar ? And then force the csroll on the datagrid which does not have a scroll ?
View 1 RepliesI have a datgridview that has two columns that allow text wrapping.When I scroll past the visible portion of the grid I can only see a single line of text even with a refresh call on the scroll event.
View 4 RepliesA program I am making required that I write my own code for column reordering rather than using the built in column reordering in the datagridview control. When I am dragging a column my code checks if the cursor is near to the right hand side of the control and if so it scrolls to the right using firstDisplayedColumnIndex.
The problem I am encountering is caused by the fact that when I do my custom dragging of columns the display index is changed not the column index itself.So when my code tries to scroll to the right using firstDisplayedColumnIndex once it reaches the very right it jumps back and forth. This only happens when I have moved the first column and thus when the first displayed column doesn't have the lowest index.
how to disable mouse scrolling only in selected combobox..ex. i want only scroll function ius disable only in combobox1 and combobox2
View 5 RepliesI'm making a program that updates a ListView filled with processes every second. After updating, it scrolls back up to the top. How do I stop it from doing that?
View 5 RepliesWhen a panel's AutoScroll is set True then it will add scrollbars for navigation of the entire size of its content. What I want is to be able to set the vertical scrollbar to go to top or zero so its contents top controls will be viewable.
View 9 RepliesI generate a DataGridView using the result of a query. The query generates a LOT of columns (more than 75). Obviously the DataGridView does not show all of them. I wrote a small procedure that extracts data from the DataGridView and generates an Excel file ora .csv file.
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Any way to "lock" columns in a data grid view so that when scrolling horizontally, the column will stay in view. Similar to the Freeze Panes functionality in Excel. I am using VB.net 2005 express.
View 2 RepliesI'm noticing that sometimes strings drawn in a given column or row will be slightly over-antialiased or altogether clipped after scrolling horizontally or vertically.I can see that the quick way to clear this up is to send a final .Refresh() call to the DataGridView after completing the scroll. But, unlike the ReSize event for Forms, there doesn't seem to be a Begin and End Scroll event for controls, so I can't just send a .Refresh() to the DataGridView after scrolling.Does anyone have an idea how I might go about detecting when a scroll event has completed so I can send that final .Refresh() to the DataGridView?
View 5 RepliesAfter scouring the articles online I have come up with this design for a winforms based touchscreen app that needs smartphone like scrolling. The app itself will run on a tablet laptop or touchscreen desktop.I put everything I want to scroll on a panel. Set autoscroll to true (which will show scrollbars)Now put this whole panel inside a groupbox.Shrink the groupbox until the scrollbars are hidden (visually hidden, not visible = false)
Now the fun part I am stuck at.I think I have to handle the mousedown, mouseup & mousemove on the panel to set the autoscrollposition so that when someone touches the panel and drags, it does it's scroll magic. Please help fill in the few lines of code in below method stubs. The msdn doc on autoscrollposition is very confusing since it returns negative numbers but needs to be set to positive with abs and what not.
Point mouseDownPoint;
Point mouseUpPoint;
Point mouseDragPoint;[code]......
I need to limit a Textbox and DataGridView to only enter text in the fixed size of the cell/textbox on the screen. So I have limited the cell/textbox so user can not change it size. Both allow multiline and wordwrap. cell/textbox is sized to accept 5 lines of data (wordwrap or enters) This is like an online form.So the text enter will be printed so I can not allow scrolling in the cell/textbox.
How can I stop the scrolling of the text inside the cell/textbox.
Also : if the user Paste into the cell/textbox how to truncate text if larger than display area.
sample settings:
DataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.None
DataGridView1.AllowUserToResizeRows = False
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I currently have a label scrolling text, But for some reason it only displays Certain song titles/text. Does Anyone know why?!
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
OpenFileDialog1.ShowDialog()
AxWindowsMediaPlayer1.URL = OpenFileDialog1.FileName
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Here's what I've got thus far:
Dim xpDoc As New XPathDocument(strXmlUrl & strXmlInfo(0) & "?xml=1")
Dim xpNav As XPathNavigator = xpDoc.CreateNavigator()
Dim xpExpression(9) As XPathExpression
[code]....
I have an small physics toy application I am developing. It works fine except the particles will not push each other away, only pull towards, I debugged that sub going through it command by command and realised the value 'H' would not change, what ever it was set to during the first pass through the sub is what it kept, the only way to change this value is to manually set it i.e 'h = 1'. Once the calculation is redone on the 'H' value it resets to what it was previously, even though the x1,y1,x2,y2 are all different, thus meaning H should be different.
I think it is me that has made a mathematical mistake somewhere, but I cannot see where it is. I need a fresh pair of eyes to look over my work. Please let me know if you find anything.
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I have been developing an antivirus using vb.net. The virus scanner works fine but I was thinking of ways to optimize the scanning speed (because large files take forever)
View 3 RepliesOk, the error I'm getting is "Load Report Failed" and it happens when I need to load a large number of crystal ReportDocument objects. I've searched on this, and there is a property in the registry that you can change to -1 and it allows to load more, however I'm still getting the error, just after I get about twice as many documents loaded.
The report is basically a one page document (for each client in the database with an interest charge). It displays the amount of interest charged, and other information pertaining to the charge. These documents are basically printed out and mailed to the client.
I created a "Print Preview" screen which has a CrystalReportViewer object, and an ArrayList property. The ArrayList property has an array of all reports, and there are next and back buttons to browse through each report. Once they are satisfied, they will print them all out, and I can dispose of the objects.
The solution for this, from everywhere I've seen, is to "Dispose the object after you are done with it". My problem is that I can't dispose it until they are finished with the print preview screen.
Is there a better way to go about this that won't require too much time to code (we are already over the deadline on this project) or a simple solution to get past the ReportDocument limit? Right now it is erroring on report 150., There are 180 records (as of today) that need to be loaded.
In a project of mine I'm currently doing this:
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all classes inherit docMain and addTemplateToList( X ) adds x to a List(Of docMain). Now my question is: Is there a better way to do what's done in the code sample? I thought of something like:
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Is this somehow possible in VB.net (Reflection?)?
How can I Optimize my own code written by VB.net? Is there any tools for it? Does Visual Studio have any one? What's your suggestion? I use VS2008 as my editor.
View 1 RepliesThe following code takes a timeframe in minutes since midnight and creates an array with minutes pr hour. But, it's slow. Any better suggestions out there? (no, changing language is not an option :-) )
Const clDeparture As Long = 123
Const clArrival As Long = 233
Dim lHour As Long
Dim lMinute As Long
Dim alHour(25) As Long
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I came across the following code recently and would like to optimize it:Public Shared Function ComputeLabel(ByVal Action As Integer, ByVal Flag1 As Boolean, ByVal Flag2 As Boolean) As String
Dim Prefix As String = ""
If Flag2 Then
Prefix = "Conditional "
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I have written a code which does the thing as the title says. The problem is, the whole process took 10 minutes just for 1000 records. Here is the code:(Written in vb.net 3.5 and sql server ce)
MyConnection.Open()
Dim count As UInt32
cmnd = New SqlCeCommand(sqlstring, MyConnection)
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