I have a form which changes every few seconds (about 10 or 15 seconds) to a different "screen" When it changes, it hides and shows different labels, changes background, and hides and shows different picture boxes.
Anyway, when it changes, there are visible black boxes and it "flashes" somewhat as well during the change. I was wondering if there was any way to reduce or completely eliminate these symptoms.
Below is the exception code info. when I try to make form visible for the first time from another form then I get an exception code. something like 'a required variable not set'
Quote:
CODE:
I'm having an odd problem when making a form visible and not visible and it not continuing to function. Here is what I have happening. I have a main form (frmMain) that is an MDIParent. On this form I have a menu to open a second form (frmCalculate) and populate a listview from Items in the database.
As I click or select items in the listview on frmCalculate the tag is read and data is pulled based on the id stored in that tag and fills in various fields on the form. This works great. However, I also have a context menu attached to the listview that allows me to perform a "what if" scenerio on the items I am calculating. When I select this menu, I hide the frmCalculate and open the frmWhatIf form where I can mess around with values on the item I had hilighted in the listview on frmCalculate. Nothing is pulled from or written back to the database here, all the information is filled in from fields on frmCalculate. It just allows me to look at rising costs and how they will affect my margins.... anyway.
If I then close frmWhatIf, it brings my frmCalculate back by setting its visible propery to true (never closed frmCalculate, just hid it). At this point if I click an item in the listview I get an exception for a null reference. IF however I never hide frmCalculate, I can open and close frmWhatIF without ever having an issue. Why do I lose the functionality to select items just by hiding and unhiding the form? As a test I added two menus to the toolbar on frmMain one called hide and one called show. I then opened frmCalculate with original menu item to populate the listview and selected a few items to test that it was working and then using the hide menu I made the form invisible and the show button to bring it back. This yielded the same exception so without even opening frmWhatIf the problem still occurs.
I need some code to draw a resizable, draggable rectangular cursor (or selection box) on a picturebox. I found some excellent code (albeit rather old) that does just that, but on a form rather than a picturebox. I have tried converting the code - basically moving things to the picturebox events (Paint, MouseDown, MouseMove etc). It nearly works but leaves a trail behind it when you move or resize the cursor. In other words, the selection rectangle is not being erased before being drawn in the new position.
Is there some fundamental difference between drawing graphics on a form and drawing on a picturebox that would cause this behaviour? Something like, when you invalidate a form and cause a redraw it erases what you did last? If not, then I just need to dig a bit further and work out how the cursor is being erased from the previous position.
Here's the original code that works fine on a form:
Private DragRect As New RectangleF(20, 20, 100, 80)
Private Adornments(7) As RectangleF
Private MouseInRect As Boolean = False
[Code]....
Is it possible to convert an object form System.Drawing.Graphics to System.Drawing.Image?
View 4 RepliesRequested were made by Businese Analyst to set the few Main FORMs VISIBLE PROPERTY TO FALSE when the POPUP FORM is loaded.
[Code].....
When the MAIN FORM loads the POPUP FORM, on the FRMPOPUPCUSTOMER-FORMLOAD even, it has to set the MAIN FORM Visible to False.
When FRMPOPUPCUSTOMER FORM IS UNLOAD it has to set the MAIN FORM Visible = TRUE.
How to the coding is to ensure that different MAIN FORM when loaded FRMPOPUPCUSTOMER it will turn the MAIN FORM Visible to FALSE.
I'm new in .Net and I have an application with windows form "LOGIN" When users enter the user and password and click "ok", then if user passes validation then I have the code Show(MDIMainMenu) (I'm trying to open an mdi form), but I receive the following error: "Form that is already visible cannot be displayed as a modal dialog box. Set the form's visible property to false before calling Show. Error Number 5"
[Code]...
Based on code that executes in Form.Load, is it possible to disable displaying that form after the handler for Form.Load is complete? I'd like to have a commandline switch that disables showing the form, but still runs the application. I've tried this, but it doesn't work:
Code:
If InStr(Environment.CommandLine.ToLower, "/trayonly") Then
Me.Visible = False
[code]......
I've got a panel - that's in a group box. All of this - with lots of other textboxes on labels - is in another panel (the big panel).I make the big panel visible and not visible based on selections made by the user.This small panel - that's in the group box. I cannot seem to make it appear.Even if I leave it VISIBLE at design time - the objects in it will not appear.Is there some kind of nesting problem that I'm not aware of!
View 9 RepliesI have five menu items that i have created as a user control and placed on the master page. Now i want one of the menu items to be visible only for particular user role and not visible for others. Here is what I did. Its not working though.
[Code]...
I have a different kind of issue inside my code. I can not use my code as era. I have a simple code to make form drop from visible status but it is not working. I could not manage this problem.
//This is my code
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
[code].....
Imports System.Runtime.InteropServices
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
[code]....
if I set the property Opacity = 0, a form becomes transparent... but become transparent all it controls, too!how to make transparent ONLY the form and let the controls, labels, buttons etc. visible??
View 3 RepliesI understand the properties to change a button from visible to invisible, but I need to be able to have two buttons alternate visibility when the first button is clicked.It's for a game. The first button is to "Begin Game" and on open, the invisible button that sits over it is called "Begin Again" which I would like to only appear once the Begin Game button has already been clicked. This would then trigger the "Begin Game" to become invisible.
View 3 RepliesWhen I make my form Opacity 0% everything disappears including controls that I know will happen im not dumb ok so I tried another method using Transparency Key I had success BUT my problem there is that when I have a picture box and an image IN the picture box around the image is the Form Background color so lets say I picked Maroon for Form1.BackColor, The edges of my image is Maroon
View 6 RepliesI am having trouble finding a way to make the form transparent but the controls still visible. The only transparency I have been able to get to work on the form is
Me.Opacity = <value between 0 and 1>
but that affects all the controls on the form Is there a way to make the controls not inherit this property from the form? Is there another way to make the form transparent? I have buttons and a checkbox that I don't want to be affected by the transparency at all, and a picturebox that I do want to be able to control the level of transparency. Currently, I'm using a slider bar, and controlling the opacity of the form, but that makes everything on the form transparent. I'd actually like for the form itself to be completely invisible, and for my slider bar to control the opacity of the picturebox only.
My graph code works but i'm afraid it may not be efficient. I'm drawing a graph on a form using GDI. Basically, i'm making the entire form one big graph. Is this the best approach to creating a graph:
Private Sub frmGraphPaper_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
Dim g As Graphics = e.Graphics
[code].....
how to draw in vb.net, and I figured the easiest way is to get my hands dirty and start coding. I figure that the best way to start is by drawing a line on the form. What I'm trying to do is use the graphics.drawline(), but I'm failing. This is what I'm using so far
[Code]...
1)Interestingly, if I try to draw on a Form with formborderstyle = none, no drawing appears.On a form, with borders; no problem
2)If I draw from wihin a paint event, i can draw on both.However, the paint event has its own issues, most irritatingly the fact that it doesn't draw immedately, but only after going all the way back through a whole chain of calls.anyway that I can draw directly on a borderless form?
Drawing with GDI+ on form load?
View 1 Repliesif I set the property Opacity = 0, a form becomes transparent... but become transparent all it controls, too!how to make transparent ONLY the form and let the controls, labels, buttons etc. visible??
View 2 RepliesI have a number of listboxes such as lstDivision1, lstDivision2 and so on. A user can choose the division they are interested in using code similar to:
For Each item As Object in lstDivision1.Items
lstDivision.Items.Add (item)
Next
These listboxes have their Visible Property set to False. The contents are copied to lstDivision which is visible on the form.What I want to know is how I can ensure that the correct listbox is being copied to lstDivision?
I have a access table column ("d") and rows with value Datetime. How can I ..... when form load make the datetime now ..visible. What is the code for making the rows with datetime value now start with index 0.
View 4 RepliesI have a form called LeaseAbstract; within the form I have two tabs: 'General' and 'Responsibility List'. In the General tab there is a checkbox called 'OutsideLease'. What I want is when the Outside Lease checkbox is checked the Repsonsibility tab becomes enabled and visible. I don't want that tab visible unless that checkbox is checked.
My code looks like this:
Private
Sub
ckbOutsideLease_CheckedChanged(ByVal
sender As
System.Object,
[Code] .....
This portion of code is in the code behind the LeaseAbstract form, I've tested it and it doesn't work.
I have a program that shows a small form appearing at the top of the right hand corner of the screen. When I switch to another opened program, the form disappears. How can I keep this form visible when I switch to another program? I set the TopMost property to true but it doesn't work.
View 1 RepliesI want my form to be invisible but I want the buttons and list-box to still be visible. So basicaly I want a bunch of floating buttons and listboxes on my screen.
View 2 RepliesThe basis of the program is that the user enters info into to text boxes then hits a button, when the button is clicked and all the parameters are met, the visible property of a rather large picture box becomes true. What I want to do is have the form start off small, just big enough to hold the labels, text boxes and buttons and then resize when the picture box is made visible.
View 2 Repliesi write Me.Visible = false a statement in the load event of the form my application has only one form and it call itself to hide. but when i run the program it doesn't hide itself i put the breakpoint on the statement to see if it even executes or not. it executes fine but no effect what it suppose to do i also have a notification icon added to a form to see it running in system tray.
View 5 RepliesI need to take a snapshot of a form which is not necessarily visible on the screen. I need to save that into a Bitmap object. I cannot use Graphics.CopyFromScreen() because if there was anything obstructing the form, it will appear in the snapshot taken.
View 6 RepliesI got a couple of issues with my windows application VB.Net. I seem to cannot set the form to be invisible before it shows up for a second, there is no option in the properties of a form and also if I set the form to visible = false before the form is loaded it doesn't work.
So this does not work:
Browser.Visible = False
Browser.Show()
and this does work but the form shows up for a second which I am still not very happy with
Browser.Show()
Browser.Visible = False