I'm a rookie at VBA(Excel) but I know some OOP stuff from java. What I want to do is extend the class MSForms.TextBox to add my own constructors and properties. I've tried using the implements keyword but my class won't compile. It would also be helpful to add these fields into some kind of container variable since they're arranged in a 9x9 pattern. Here's what I want my custom textbox to do. (It's for a game)
I need to be initiate it and place it on the form and put initial text into the box based on what is passed to the constructor. I also would like to have it check the values at runtime with an event to make sure they comply with the game rules. If it does not comply I would like to change the background color to red.
I'm able to do all of this when I just make a bunch of form controls the old fashioned way and use a sub controlled by a button to check the text box values.
Any help on extending classes would be much appreciated.
Thanks
I don't think you can do that in VBA. I would keep two arrays, one array of TextBox and one array of a new class representing your extended properties. Then you keep them in sync. e.g. Textbox #71 and extended properties #71.
You can look at the following link for making and working with control arrays.
http://www.siddharthrout.com/index.php/2018/01/15/vba-control-arrays/
Related
To illustrate what I'm asking, let's say I have a custom TextBox that has 2 modes. Mode 1 only allows numbers, and mode 2 only allows dates in a particular format.
Using a class module I can create this custom TextBox, and I can use a loop when the userform initialises to set which TextBoxes are custom.
What I'd like to happen is have the custom TextBox, or what ever custom control I want, show up in the toolbox. And I also want its custom properties, if they exist, to show up in the property window.
So far, I've been unable to find a way to do this. In fact, I've been unable to find out if it's even possible. It seems, to me anyway, that it's something that should be possible, but maybe I'm barking up the wrong tree. If it's possible I'd really appreciate being pointed to a resource.
I am quite new to visual studio. Developed previously with vba.
Encountering a problem writing a language translation class.
The language dependent values are stored in a localdb table every row having formname , controlname and controlproperty as wel as a column per language.
The Language class Handles the translations at runtime. For forms I use a Sub FormUpdate(frm as Form) called from the form's load event as FormUpdate(Me) it checks the form's language kept in a custom parameter against the current language and updates the .text property of the controls on the form that are exposing some language specific text (Buttons, Labels, Tabcontrol etc..).
However I could not solve how to access and update the form's Tooltip component from the language class. (in vba it was easy as every control was exposing it's Controltiptext property)
In the form's class you would use MyTooltip.Settooltip(CtrlName,Text) but I could not figure out how to do that from another class (the tooltip component is not part of the form's controls - and I could not figure out nor find info how to do it) ??
Could someone advise pls?
I was so focused on finding a similar way to the one I used before that I did not see the easy way to resolve it - not yet enough accustomed to the new environment.
Sure, I am interested in an answer to my question but instead of making it too complicated using external components I'll do it the easy way by overloading the FormUpdate sub adding a sub with an extra parameter as Tooltip.
Setup:
I have created a Form that I wish to have serve as the base from which I will inherit other forms. This base form serves as a "template" of sorts, but it also provides a good deal of functionality related to the structure, as well as the interrelation of all of the controls provided.
A primer for the images that follow... The top info-colored bar is a custom control inherited from ToolStrip. The bottom strip is another custom, again inherited from ToolStrip. The left white block is a TreeView and the right block is a TabControl (having deleted all TabPages from it...I intend for these to be added in the inherited forms).
Image of base form in designer:
Image of inherited form in designer:
Clearly, the only difference is that when I open the inherited form, I get a little box icon superimposed over each control, and when I click them, I get the padlock telling me I cannot edit.
The problems:
All controls on the inherited form are locked. I have researched the issue of visual inheritance, and as far as I can tell, I'm not using any controls that expressly do not support it, as this link suggests there are. In this Q&A, Hans suggests changing the modifier on those controls, which I have done. In fact, I tried both Public and Protected, all to no good result.
I am stumped.
This is a technical restriction in the designer, it is specific to the SplitContainer control you are using. And some other ones. The trouble-maker is the ISupportInitialize interface.
Controls use this interface when they can't afford the properties of the control to be assigned in an arbitrary order. The designer helps when it sees that the control implements this interface, it calls the BeginInit() method when it starts assigning properties, EndInit() when it is done. The control uses these methods to delay the side-effect of property assignments, the EndInit() method makes them effective. Important for SplitContainer, the minimum sizes of the panels also affect the splitter position.
Perhaps you can see the rub, the InitializeComponent() method in the base form class has already called ISupportInitialize.EndInit(). So modifying properties again in the derived form class is unlikely to turn out well. The designer protects the control from this by locking it.
Very inconvenient, there is no simple workaround. If modifying the SplitContainer in the derived form class is a hard requirement then you'll have to give up on inheriting it or write the code by hand in the derived class constructor.
I am trying to broaden my knowledge of user controls or to be more specific, composite user controls. Msdn has a walkthrough on the subject here which although not in VB is easy enough to follow and get results.
What I had had in mind was to create a base user control comprised of a split panel, one half of which would be used to display dynamic help and the other half which could house whatever controls the new user control which would inherit from this required. The problem that I am facing is that when I then create a new inherited control based upon my base control I cannot add new controls to the design surface. If I don't have a split panel filling the entire design surface of the base control I can add new controls, but if I do I can't.
Either I am doing something wrong, or more likely failing to do something on the base control that I ought to do , or this can't be done which I find odd to believe. I'm hoping someone can explain what it is I've missed.
This is being targeted at winforms with vb.
Thanks
Well, Did you make the split panel's modifier to protected or protected internal or public? That should do the trick.
By default it is private and so designer will prevent you from accessing it.
I have two controls. The XAML's are big and very similar. One difference is this: they contain a listbox, in one control, it's bound to {StaticResource X}, and is multiselect, the other is bound to {StaticResource Y}, and is not multiselect. The code-behinds are also very similar. How should I combine these two classes into one? I thought about creating a base class and deriving my 2 controls from it, but I have no idea how to do that with XAML. I know I could make it easier if I set the differing properties in code instead of XAML (in which case the XAML's would become identical), but let's consider that plan B. Silverlight has no StyleSelector, it seemed like a possible solution though. Maybe VisualStateManager could do it, except it sounds bad, because my problem has nothing to do with visuals, but maybe I could define 2 states anyway. Except I think SL doesn't support binding in style definitions. Tough question for a beginner like me...
You should look into creating custom controls and using AlternateContent properties. Look these up and you'll find hundreds of tutorials.
Here's a quick google search to get you started with alternate content.
So, to sum it up, I want one control which can work in somewhat different modes, or states. The mode can affect XAML properties and code logic, too.
It seems like VisualStateManager is very limited in which properties it can manipulate. But when the differences are only visual, it's the best choice.
When there are other differences in XAML, then the obvious choice is to omit those properties from XAML and set them in code, like in the ctor. A nicer way is to expose those properties as dependency properties in code, bind to those properties in the XAML of the user control, and then you can specify those properties in other XAML's where you use this user control. When your control doesn't care what's in those properties, then it's a good design choice, too. In my case, though, when setting up those differing properties should be the responsibility of the user control itself, not its parent, and I want to expose a single mode property only, it's not good.
For this case, the best way I found so far is this:
create a normal user control (XAML+code), expose the differing properties (simple, not DP's) and bind to them in XAML
make this user control abstract, and possibly some properties, too
for each different mode the control needs to support, derive a class from this base control (code only, no XAML), provide implementations for the abstract properties
instead of using the base control in other places, use one of the derived implementations
This way, you can easily specify from outside which mode you want your control to work in. The drawback is that it's not easy to change the mode, since it's not a property you need to change but the type and instance of the control.
And finally, when there are code logic differences, too, then one way is exposing a mode property, or using the abstract class method I described above. For example, a button click handler function can be abstract, too.