I have a following scenario:
I have two forms (UI). From the first UI, user is navigated to the second one.
In the second UI, I have a label and a button. When user presses the button, the text of label is increased (from 1,2,3, and so on.)
I would like to achieve this by adding a integer variable whose value is 0 initially. When I press the button, I will increase the integer value by 1 and set the integer text in the label.
This logic may make no sense but I am trying out just to be clear on concept.
My question is, where should i keep this variable. Usually, we have separate classes for each UIs. On each UI, we declare necessary variables which are private and not visible to other classes and use that variable within that UI class.
But in code name one, the structure seem to be different. We have a class StateMachine, which handles all the things of all the UIs (like click event, page load event, etc.). It seems we do not have any privacy between the UIs.
Is there any specific way that I can use different classes for each UIs?
The StateMachine is just the GUI Builder way, you can also create a "manual" project and code all the UI by yourself.
Related
I'm developing a WPF application that contains a lot of forms (about 20 different forms)
each form is connected to a ViewModel class that usually hold a single object that the form is editing its properties.
I need to give a graphical sign to the user if he changed something like in Word when you edited the document and it tells you need to save it.
If the user edited even one property I need to show that sign.
Is there a simple way to accomplish that? I don't want to create an event for every property editor I have (there are more than 300 of them).
Why not use INotifyPropertyChanged?!
Since you are using WPF, you can opt for SourceTrigger to Property Changed.
Check here, http://www.codeproject.com/Articles/15822/Bind-Better-with-INotifyPropertyChanged to know about using INotifyPropertyChanged.
I'm writing a WPF application while mostly adhering to the MVVM design pattern. The application has various educational modules broken up into different categories to be accomplished by the user. The modules are organized into a hierarchical menu. My ViewModel has a class called MenuPageViewModel which exposes the information needed to render a MenuNode. Naturally, the terminal elements in the menu tree have content that I'd like to display to the user. This content can be one of many different types of modules. Currently, when the user selects a module in the menu, I can't see any way around using a large conditional block to determine what type of ViewModel I'd like to return to be displayed based on the type of the MenuItem's Content Property. For example...
if (CurrentlySelectedMenuItem.Content is Lesson)
return new LessonViewModel(CurrentlySelectedMenuItem.Content as Lesson);
if (CurrentlySelectedMenuItem.Content is SkillsCheck)
return new SkillsCheckViewModel(CurrentlySelectedMenuItem.Content as SkillsCheck);
Can someone give me a hint to a more elegant and maintainable approach? Right now, if I add a new module type, I have to remember to update this conditional block, and that just sort of annoys me.
Thanks.
If you are using Unity/Prism then using the container to resolve the object would be my first preference.
_container.Resolve(Type.GetType(strObjectType)) as BaseViewModel;
where strObjectType is a string with the type of class you want to create (eg "LessionViewModel" )
if you are not using Unity, then reflection works
Activator.CreateInstance(strObjectType) as BaseViewModel;
with both solutions you need to have the string with the class type on your menuItem.
A third option is to have a factory, but it would probably end up having a conditional situation within it or will contain the code i just listed.
I searched and Googled first, thinking surely someone must have asked this before, but I sure can't find a good description of this problem.
I have six or eight similar C# .NET 2.0 WinForms applications built with the fairly common model of a main application window with several GUI data fields plus several modal dialogs for further data collection. Many of the data fields (especially TextBoxes) have identical data validation routines. I'm writing the same xxx_Validating() routines over and over, which in the simplest case only capitalize the first character of the entered text (if any) and redisplay the result. I have another one for ZIP Code fields that takes the first 3 digits of a 5-digit US postal ZIP Code and returns the corresponding State, using a 1000-member string array. Simple stuff. There are a few others; here's an example:
public void CapFirstCharTextBox_Validating(object sender, CancelEventArgs e)
{
string strValue = ((TextBox)sender).Text.Trim();
if (strValue.Length >= 1) {
if (char.IsLower(strValue[0])) {
strValue = strValue.Substring(0, 1).ToUpper() + strValue.Substring(1);
((TextBox)sender).Text = strValue; // fires (whatever sender)_TextChanged()
}
}
}
Again this is part of a half-dozen or so such "utility" routines. I've only got one set of these per dialog box class, and all the various TextBoxes in that dialog which need this have their Validating event pointing to the same method. So it's not like I've got 20 of these in a given source file (one for each TextBox) or anything; there's only one for the whole dialog class.
Problem is, the whole set of these exists in every source file where I need them. That's one set for the main window and more for each pop-up dialog box -- and that's too many. I understand modal dialog box classes can't communicate with each other, and making all this stuff global is elusive at best and a big "no-no" at worst.
I have successfully tried passing a reference to "FormMain" (where one copy of these routines exist) to the various dialog constructors, and then calling these validation routines with that from their own validation handlers. It works but feels awfully clunky and certainly not like the best approach.
So, how would I (or would I want to) rearrange the project and organize the code better to have only a single instance of these kinds of things? How would I wire up a global "utility" class of such methods such that I can get to it from the main form's code and from that of a bunch of pop-up modal dialog boxes as well?
I'd like to maintain just one executable with no additional .DLLs if possible (these are all one-project-per-solution, by the way), and if practical I'd like to further be able to share that common code across multiple solutions.
I think the answer will include writing new assemblies, using different namespaces (currently all my code in a given project is contained in the same namespace), and maybe separating this stuff out into its own project in the same solution file.
Is it possible?
You can share code across solutions by keeping the code in one place and adding a link to the file in each solution.
To add a link: right click the project (or folder) you want to add the code to, then select "Add existing item", browse for the file, when found click the down arrow on the button and pick Link to.
This way the projects that link to the file will share the same code.
BTW: take care when using a source control system that doesn't know how to handle these links.
In order to make a convenient UI for an .Net 2.0 Winforms application I am working on, I have need for a control that I'm pretty sure goes beyond the "out of the box" behavior of any standard control. A mock-up of what I'm trying to achieve follows:
Mock up http://www.claware.com/images/temp/mockup.png
Essentially, this part of the application attempts to parse words into syllables from tribal languages (no dictionary to refer to; any and all unicode characters are possible.) By the time the user gets this far, he has already defined the vowels / consonants in his language and some other configuration. There is then an iterative process of (1) the application guesses which syllables exist in the language based on some rules, (2) the user refines the guesses, selecting the correct parsings or manually parsing a word, (3) the application "learns" from the user's feedback and makes smarter guesses, (4) repeat until the data is "good enough" to move on.
The control needs to present each word (the grey headers), then all the syllable break guesses (the white areas with dots separating the parts of words.) There is also a way to manually enter a parsing, which will display a text area and save button (at the bottom of the mockup.) When the user hovers over a guess, the background changes and "accept / reject" buttons appear. Clicking on the accept, or entering a manual parsing, removes the entire word from the list. Clicking the reject button removes just that item.
I'm by no means 100% sold on the formatting I have above, but I think you can get a general idea of the types of formatting and functional control I need. The control will also scroll vertically--there may be thousands of words initially.
My question for you experienced WinForms developers is: where to start? I would really, really like to stay within the .Net core framework and extend an existing control as opposed to a third-party control. (At the risk of starting a religious war: yes, I suffer from NIH-syndrome, but it's a conscious decision based on a lot of quick-fix solutions but long-term problems with 3rd party controls.) Where can I get the most "bang for my bucK" and the least reinventing the wheel? ListView? ListBox? ScrollableControl? Do I need to go all the way back to Control and paint everything manually? I appreciate any help that could be provided!
[Edit] Thanks everyone for the ideas. It seems like the most elegant solution for my purposes is to create a custom control consisting of a FlowLayoutPanel and a VScrollBar. The FlowLayoutPanel can contain instances of the custom controls used for each word. But the FlowLayoutPanel is virtual, i.e. it only contains those instances which are visible (and some "just out of scroll"). The VScrollBar events determine what needs to be loaded. A bit of code to write, but isn't too bad and seems to work well.
I would look at the TableLayoutPanel and FlowLayoutPanel controls. These will let you organize a series of controls with moderate ease in a vertical fashion. I would then create a UserControl that consists of a label and 2 buttons. The UserControl will expose properties like Text and events that are exposed for the button clicks.. For each entry in the list, you will create an instance of the UserControl, assign the text value, and handle the click events. The instance will be placed in the Table/Flow panel in the correct order. Both of those layout panels do allow for inserting items between other items so you can add/remove items from the list dynamically.
Edit:
Given the length of what you are trying to render, I would consider using the DataGridView and do some custom rendering to make it perform how you want it to work. Using the rendering events of the DGV you can merge columns, change background colors (like highlighting the dark gray lines), turn on/off the buttons, and handle changing the grid into edit mode for your rows to allow modification or inserting of new values. This method would easily handle large datasets and you could bind directly to them very easily.
Well, this certainly looks like a candidate for a custom component that you should be creating yourself. You can create this using standard .Net drawing commands along with a text-box, and a regular button control.
Now you want to find out where to start.
Create a Windows Forms Control Library project.
Drop in the textbox and the button control.
The panel drawing code should preferably be done by code. This can be done using the regular GDI+ commands.
Edit:
Here's another idea, and one that I've practically used in my own project with great success.
You could use a web-browser control in the app, and show your data as html. You could update the source of the web-browser control based on the input in the textbox, and clicking on the links in the web browser control will give you the event that you can trap to do some action. Your CSS will work.
I used this technique to build the 'desktop' in an app I made called 'Correct Accounting Software'. People loved the desktop so much that it is one of the best loved features of the app.
Here's how I would do it:
Create a custom control. In this custom control, have a ListBox atop a LinkButton, and when the LinkButton is clicked you can make it give way to a TextBox. The ListBoxes will have the top row unselectable... you can probably get the rest from there. When you get your list of words, fill a Scrollable of some kind with one control for each word:
(foreach String word in words){
myScrollable.add(new MyComponent(word));
}
From there, I'm not sure what you want to do with the boxes or the data, but that's my initial idea on the UI setup.
Use the WebBrowser control and generate the HTML markup into it using DocumentStream or DocumentText.
I have a windows forms application with controls like textbox, combobox, datagridview etc.
These controls allow a user to use the clipboad, i.e. cut/copy and paste text. It is also possible to delete text (which is not related to the clipboard).
My application has a menubar with an Edit item containing Cut/Copy/Paste/Delete items, and a toolbar with these items as well. How can I enable/disable these items properly depending in the state of the control having the focus?
I am looking for a generic way, i.e. I look for an implementation I do once, and can reuse for the future independent of the controls my application will use.
There is no generic interface or set of methods for getting cut/copy/paste information from a windows forms control.
I suggest your best approach would be to create a wrapper class for each type of control. Then when you want to update the menu state you get the current control with focus and create the appropriate wrapper for it. Then you ask that wrapper for the state information you need. That way you only need to create a wrapper implementation for each type of control you use. Bit of a pain to start with but other time you only need to add the new controls you come across.
Clipboard information is much easier as you can ask the Clipboard singleton if it has data inside and what type it is. Then again you still need to ask the target control if it can accept that type of information so there is still extra work needs doing.
Create an array for each enable/disable group. Add the controls to the array (of course it has to be of the correct type such as Object or Any, etc. depends on the programming language you are using).
Then to enable, disable just loop through the array and invoke the enable/disable method or function for each control. Again, depending on the language you may need to cast back.