Preventing Controls Enable Property From Changing?
Mar 9, 2010
I m implementing control based security in my application. where i m saving controlname (per form) in database, which are to be restricted. So far I have implemented the security and restricted control get disabled.
Now what i want to do is that i have to prevent that for those controls the "control.Enable" property should not change. how can i restrict that.
I have achieved the functionality by canceling enable=true property in "Invalidated" event of the control. but this is not some generic way. I have to map this event for all controls in all forms :(.
What i really want is that as all my froms are derived from same parent which implements the security. so the parent should some how restrict enable property from changing.
So,HOW CAN I PREVENT CONTROL enable property from changing in their parent class?
Let's say I've got a TableLayoutPanel with 50 cells in it. Inside each cell is a separate text label. If I want to change the color of each of those 50 labels at run-time to the same color, is there an efficient way to do it? (so that I don't have to write 50 lines of LabelX.ForeColor = X, etc).
Not that I would mind writing 50 lines of code for this, but I would like to figure out the most efficient way to do this sort of thing, for future reference.
How would I code it so that I can use a random to add the number of the control so that a random control will be enabled. I.E. I'm trying to make a duck shooting game, random will get a random number then append that number to "picturebox" so that it becomes "picturebox36" to "picturebox70". Then I wall use that string along with ".enabled = true" in order to enable it.
So far I have this:
Public Class Form1 Dim RandomA As New Random Dim rnd As New Integer
I am about dead certain that in VB Express 2008 that I was able to have multiple tabs. And, on each tab I put controls. I could also click on a tab and see the controls only on that tab.I am now in Visual Studio Pro and I cannot for the life of me look at what is on a specific tab. Only the first tab wants to shows its controls.Does anyone know how to enable the environment to allow me to view the controls on different tabs?!
I am trying to use (and this may be my problem already) e.Graphics.CopyFromScreen() in the OnPaint() method of my control to prepare a background onto which I can draw the content of the control. The goal is a tool-tip with rounded corners and other specific features to replace the default Windows tool tip.
Ideally the tool tip could be antialiased and blended into the backdrop, however at a pinch I could tolerate an aliased boundary. This may also be necessary as the control will often be covering a control with an OpenGL overlay and the whole blending procedure may end up a nightmare.
I have created a custom user control, a persistent instance of which belonds to my applications's main form, overriding the OnPaint and OnPaintBackground methods. The application of transparency however is challenging. As I understand, the graphics object passed to the paint method starts with a copy of the current VisibleClipBounds, where generally the first move is to clear the control with a solid colour and start drawing the main features. My first thought was to bypass the fill and start drawing on the captured background. For the first redraw this works fine, but subsequent redraws keep the previous content instead of re-capturing the backdrop. I hoped that CopyFromScreen would specifically eliminate the currently drawing control from its capture so as to start from a clean base but this is not the case, it captures the rectangle of the new location including the image of the previous location if it is in the bounds.
I am using a custom built driver to communicate via Modbus TCP with a Windows CE Controller.
There is a property declared in the driver as a SHORT. I need this property declared as a LONG. I have tried everything I know of to change this programmatically but I am having no luck.
' Declared in the class Dim dev As vHMIModbusMaster.CDevice 'this is the Modbus Comm Library Dim WithEvents MBSerial As vHMIModbusMaster.CModbusSerial Dim WithEvents MBEthernet As vHMIModbusMaster.CModbusEthernet
[Code]....
Address is sent to the event from a timer event. It is the .Memory_StartAddress that I need to be a long.
I come from a VB6 background and have only recently started using .net. The developer of the driver has been very slow to respond and I am having a hard time convincing him that the problem is with his code. The thing is that it works fine as long as I send an address less than 32767.
I have a form which has ONLY three buttons. Somehow they got named Button5, Button6, and Button7.
When I try to rename them Button1, Button2 and Button3 to match code, I get a Dialog box which, if I look at Details, says the Button name is already in use.
Is there something I can do to enable the renaming?
I have a form with a dropdownbox two listboxes and two buttons on it. I removed a "select" button as I just used the DropDownList1_SelectedIndexChanged, but the event would not fire until I used the suggestion from:Why DropDownList.SelectedIndexChanged event does not fire?
It involved changing the AutoPostBack='true' and EnableViewState="true" properties
So now the DropDownList works but with the two listboxes, the SelectedIndex stays as -1 and does not change even when selected.
[Code]...
I think it has something to do with post backs, page_load or the selectedindex changed event of the listbox, it worked perfectly before I made the modifications.
I need to use a Vertical Scroll Bar to scroll through some controls (an array of checkboxes to be precise) on my form. Their number changes depending on the user's requirement during program execution so I need to change the Maximum value of the scroll bar in my code. Also, the SmallChange property needs to be modified depending on the set maximum value (other wise scrolling through the controls will take ages ).
Is there an "easy" way to change a control's ForeColor when it is diabled? Yes, I know that this goes against the Windows standard.
On our forms, we have buttons with a dark blue background and a white foreground (the design is dictated by marketing). When the buttons become disabled, the ForeColor goes to a dark color making the button unreadable.
Is there an efficient method of changing the opacity of a panel and it's controls? OR Is there an efficient method of changing the opacity of a MDI child?
I dynamically add picture boxes to a vb.net form. However, when I add the new picture box, it is always under/below/behind the picture boxes that I previously created. Is it possible to change it so that the newly created picture box would always be in front of the others?
I'm trying to change the look of some controls in VB.An example would be a button, I now have a stack of 4 images on top of eachother. By using the mouseover events and such, I get the same result as a normal button. However, I'd like to be able to insert those images into a normal button like thing.
I know it's possible to do this by creating a custom control, but that'd end up with the exact same code, just in a different file.
However, the real issue would be a dropdown box and slidebar. I'd like to get them to look nice with my theme. (Background, buttons, borders. Things like that..). I got absolutely no clue on how I should do that.
I know that there's a tool to create controls, but that's from scratch and I can't get a grip on it, at all.
What I am trying to do is have a Form which can dynamically change the controls which are on it and their properties; this allows my main GUI to be more fluid and not have tons of groups and controls on it which I must hide and show when needed. To make this as extensible and reusable as possible, however, I want all the control additions/subtractions/edits to occur through a separate DLL which I write. The problem is, I can't seem to instantiate any controls in the Class Library because I cannot import 'System.Windows' or any of its children ('Forms').
I am inheriting my own datagridview (say MyDataGridView) from the standard datagridview control. What I want is that certain properties of MyDataGridView should have a different default value than what its base have. For example, AllowUserToAddRows,
There is no BackStyle property in Visual Basic 2005 ... But I read in MSDN that changing the BackColor of label control will make the background of label control Transparent ... So we'll be able to see through the label control ... I changed the BackColor property to Transparent but it didn't work for me ... BackColor changed to Transparent ... But still I ain't able to see the image behind the label control ... (PictureBox) ... Background color of label still remained the background color of Form i.e. Control color ...
I have an Enum file, as shown in first code block. Though it's first time I use an enum file, so maybe it's not correct to use it like this.. My purpose is just to be able to reference a global parameter from anywhere, so I can just type DataInterval.M1, and it will be treated as an integer... or.. will it not ? urther I have a property in my DataSeries class, of type DataInterval. And in this class I also have a bunch of methods Get/Set etc. to do different work on the dataseries (Inherits List(Of BarData)). roblem: The interval property keeps changing unexpectedly every time the GetNextCloseTime function is called.
''' <summary> ''' "Time Frame" of data series ''' </summary>
My program has two lists, one a listbox and the other a listview viewed in details mode.
Both of them change heights (get taller) for no obvious reason. I am having to add a call to a method that resizes them to the end of every method, which is kind of absurd, I think. Also, when the window size is changed, these components change size, which means I have to keep track of that.
Edit: I had also thought of adding a timer to handle this.
I added a groupbox and changed its heading's font and fore color. The problem is that, when I add a button to this groupbox, it automatically changes its font and fore color to that of the groupbox!How to prevent this from happening?
I'm trying to create a button that will hide the panel that I have docked at the centre of my user control. [code]This works to an extent. However, when the bottomPanel is set to Fill it seems to fill the entire control, and not just up to toolStrip1. Can anyone tell me why this is happening, and how to correct it?
I have created several simply custom controls and I used them in my app. Now, I changed the background color in a custom control class, because I wanted an other color for this type of control. But in my app, the background of this controls didn't change. Why? I assume, I don't need to place again this controls on each forms to get the new background color, or do I? If yes, this is very stupid in my opinion.
I'm trying to edit the text of a toolstripstatuslabel from a module in my project, but whatever I do, I can't change it. [code]But that didn't work either.I tried to change If Me.StatusStrip1.InvokeRequired Then to If Me.InvokeRequired Then, but that didn't help either. I also tried to change the modifiers property of the toolstripstatuslabel to public, with no result.
how to turn on allowheaderfilter property to true for a specific column. It appears that I can only do this in design view. I must be able to do it code behind as I have certain conditions when this can be done.
I have come across a problem with visual studio 2010 & vb.net. i have a few custom controls on the form and few standard controls. When i build the application, the custom controls automatically change size and location. Anchoring and Dock properties are fine. Anchored to Top Left without dockstyle. Even if i fix the location and size in design mode, after i run the application the controls again change back to weird position.
how to change the properties of control which are created at run time. The actual situation goes like this: I will be creating 4 picture boxes at runtime and assigning pictures to them. Now if i wanted to change those pictures, i am not getting how to call those picture boxes.
All my forms inherits from one base form where we handle background paint and set standard properties. Recently, I think of cheching if the app is running on Vista or Later to use Segoe UI font, and I added this. The problem is than inherited forms changed sizes and their inner controls changed also... even PictureBoxes! The controls and forms seems to be thinner (in width), so square picturebox became vertical rectangules!
