Programmatically changing form controls - c#

I'm not sure if this can be done but I'd like to know if it is possible to completely alter what controls are on the form programmatically, similar to what happens with installers; when you click the next button the form doesn't hide or close and open the next form, it mearly loads a different set of controls(at least, that's how it appears).
Is it possible to do this with C# in Visual Studio? Or do you have to use tabs or hidden panels?

I think what you're looking for is UserControl. A UserControl is like a form in the way you can use it as a container for other controls.
You can find a walkthrough here.
In the case of installers you mentioned or wizards in general you can design a different UserControl for each step and load each of them in a reserved area in the form. The reserved area can be a panel.
for example assume you have a button which calls a method with wizards step number as parameter:
UserControl _step1Control = new UcStep1Control;
UserControl _step2Control = new UcStep2Control;
private void SetStep(int stepNumber)
{
panel1.Controls.Clear();
switch(stepNumber)
{
case 1:
panel.Controls.Add(_step1Control);
break;
case 2:
panel1.Controls.Add(_step2Control);
break;
default:
break;
}
}

Yes you can do anything to the controls programatically. The designer that you use also generates C# code in the background.
In order to add a new control to your form, you use the the Form.Controls.Add(Control c) method. Any class which inherits from Control (Button, ListBox, etc) can be used. To remove it, you use the Remove method instead of Add.

Related

Winforms Adding and remove UserControls

So I have an application that uses a single master form with a menu along the left-side of the form.
On the right-side I have a panel that acts as a placeholder for any UserControl I have created.
Each time a user clicks on a menu item, the related UserControl will display using code like this:
//Display UserControl first
ucMyUserControl uc = new ucMyUserControl ();
uc.Dock = DockStyle.Fill;
pnlContainer.Controls.Add(uc);
Is there a better way than to just copy and paste this for each button or whenever I want to display a UserControl. Should I be creating a function to call each time and just passing the name of the UserControl I want to use?
Maybe I've got it all wrong in the first place with the way I'm using it - I'm new to this concept and just trying things out.
Sure, don't repeat yourself. Write DRY code with a helper method. It could look like this:
public void ShowPage(UserControl uc) {
while (pnlContainer.Controls.Count > 0) pnlContainer.Controls[0].Dispose();
uc.Dock = DockStyle.Fill;
pnlContainer.Controls.Add(uc);
}
And now you simply call ShowPage(new ucMyUserControl());
Note that the quirky looking while-loop is important, you don't just want to use the Controls.Remove() method. Disposing controls that you remove is very important, if you don't then they'll live forever and ultimately crash your program.

Multiple forms one windows C# possible or only panels/usercontrol?

So here's my Question, I'm new to C#(teaching my self at that) Here's the thing, I'm working on a basic sim game, nothing to complex but I've got the design and basic functions done.
However In order to implement it, I'm currently using multiple Forms(Visual Studio 2013)
I have my "main" form which has the "action" buttons to it
So when i want to go to a user Profile page I have
Btn_profileview Click(object sender, EventArgs e){
Form profile = new Form();
profile.Show();
}
The User would then implement the changes(for instance change name) which is written to a text file, for use in other areas of the program.
However It opens a new windows, I've tried modal and nonmodal windows and while the benefit of Modal so they have to actual close the window solves the issue, i'd rather have it just overwrite the preexisting Form, and then on close go back to the "main" screen without actually using multiple windows.
Now I was told UserControl and/or Panel would solve the issue, but it would cause a complete redesign moving from the multiple forms to the multiple panel screens and figuring out how to get those to work(Visible and Invisible), i'm assuming it wouldn't be extremely difficult something along the lines of Panel"name".show(); and panel"name".close();
But would it be possible to actually add a line of code to the pre-existing code(so as not to cause a complete reesign) or are Panels and UserControl the only real way to implement within 1 continuous windows?
paqogomez is right: There are many ways to do it.
Here is one that combines a lot of the pros:
You create an invisible Tab on your window with as many pages as you need. Place a Panel on each tab and create all your controls on of them. This does not mean that you have to do it all over - you can move and drop the controls you already have without much hassle. Of course you need to turn off docking and maybe anchors, but other than that this is a simple process.
If you have controls on the 2nd form with the same name, these names should be changed to something unique though. I hope all Controls have proper names already, but especially Labels get neglected, at least here.. (With a little luck you can even use cut and paste to get Controls from another form to panel2!)
The big pro of this trick is that you can do all work in the designer of the same form. The Tab control serves only as a container where you keep your panels without adding to the UI and without giving the user control of what is shown.
Next you create one Panel variable in your main form:
Panel currentPanel;
On Load you assign the first 'real' Panel to it like this:
currentPanel = panel1;
this.Controls.Add(currentPanel);
Later, each time you want to switch, you re-assign the panels you need like this:
this.Controls.Remove(currentPanel);
currentPanel = panel2; // or whichever panel you want to show..
this.Controls.Add(currentPanel );
If your real panels are docked to fill the tabpage, as they should, the currentPanel will fill the form. You still have access to each panel and to each control by their names at any time but you see no overhead of tabs and your form never changes, except for the full content.

C# Using a form to load other user controls and have access to a base control or property

Currently I have a C# program with a windows form and then a user control template put onto the form. The user control template is really just used as a placeholder. I have a series of other controls which inherit from this user control template.
Each of those controls have navigation buttons like 'Continue' and 'Back' on them and each control knows which control needs to be loaded next. However what I need to figure out is an easier way to have variables that are global to these controls.
The only workaround I have is that I pass the form to each control when they are loaded and use variables inside of the form to read and write to. What would be the proper way to have each of these user control screens be built off of a base control which contained objects all of the controls could get to?
Sorry for the rambling nature of the post but I've been thinking about this problem all morning.
Here is some of the code:
Most of what I have written was based on hiding and showing the user controls so that content in the controls wouldn't be lost during navigation. I won't be needing to do that as eventually it will be loading the fields of data from a database.
Code for initially loading control from form click:
conTemplate1.Controls.Clear();
conInbound Inbound = new conInbound(this);
Inbound.Dock = DockStyle.Fill;
Inbound.Anchor = (AnchorStyles.Left | AnchorStyles.Top);
conTemplate1.Controls.Add(Inbound);
Code for Continue button inside of one of the controls:
if ((Parent.Controls.Count - 1) <= Parent.Controls.IndexOf(this))
{
UserControl nextControl = new conPartialClear();
nextControl.Dock = DockStyle.Fill;
Parent.Controls.Add(nextControl);
this.Hide();
Parent.Controls[Parent.Controls.IndexOf(this) + 1].Show();
}
else
{
this.Hide();
Parent.Controls[Parent.Controls.IndexOf(this) + 1].Show();
}
The best-practice for communicating from a control to a parent is to use events, and for communicating from a parent to a control is to call methods.
However, if you don't want to or can't follow this practice, here's what I would recommend.
Each UserControl has a ParentForm property that returns the Form that contains the control. If you know that the UserControl will always be attached to MyParentForm, you just cast the ParentForm and then you can access all public controls, methods, etc.
Here's what I mean:
public class conTemplate
{
public MyParentForm MyParentForm
{
get
{
return (MyParentForm)this.ParentForm;
}
}
}
This way, you can easily access any public members of MyParentForm. Your conInbound class could have code such as this.MyParentForm.GlobalSettings.etc..., and could even have access to any public controls.
I'm not totally sure I understand your problem. It sounds like you want the user control to "do something" with it's parent form. If that's the case, you may want to consider adding events to the UC and then handle them on the form itself.
Basically, for your UC's "continue", you'll have an event that's fired when it's pressed. You'll want to handle that in your form. I'm not real sure about the syntax from memory, or I'd work something out for you code-wise. But I think that's the route you'll want to take. Think of your UC like any other windows form control. If you add a button to your form, you assign it it's event method. Do the same with the UC.
I found this and thought it may be helpful. Scroll down to where it talks about UC's and events.
http://www.akadia.com/services/dotnet_user_controls.html
Hope this helps.
EDIT after new info from OP.
You could declare a global variable inside the UC of type yourForm and then set that variable to the ParentForm at run-time, if I'm understanding you correctly.
So, inside your UC Class, you could do:
private parentFormInstance;
then inside the constructor of the UC, you could set it as such:
parentFormInstance = this.ParentForm; (or whatever the property name is).
This allows you at design-time to use:
parentFormInstance.DoSomething();
without the compiler yelling at you.
Just basic advice, but if you can go back and make it easier on yourself, even if it takes some additional time re-working things, it'd be worth it. It may save you time in the long run.

How can i programmatically add a Tab to a form during runtime?

I googled this and still cant get it to work. I know how to add a tab using the toolbox. I have also read about how to do it programmatically, but i still dont get it. (MSVC# Express 2010)
I have an easy project set up. Just a windows Form with a TabControl in it, i used the Designer to add a new TabControl and made that TabControl public instead of private.
I wrote this code to
a) access the Windows Form
b) add a tabpage.
The code compiles just fine, but the Tabpage is not displayed during runtime.
static class Program
{
[STAThread]
static void Main()
{
Application.SetCompatibleTextRenderingDefault(false);
Application.EnableVisualStyles();
Form1 ApplicationMainForm = new Form1();
Application.Run(ApplicationMainForm); //LABEL B
ApplicationMainForm.tabControl1.TabPages.Add("MyPage"); //LABEL A
}
}
How can i get the form to display my Tabpage?
My TabPage is displayed when the Lines A and B change position. Am i missing an update method, oder is the TabPage Add never called until the application closes?
Edit #1: Some minor edits.
Edit #2: Edited in some more examplecode.
Edit #3: Removed some earlier / irelevant points.
Edit #4: Found a hint and edited this information in
Form1.tabControl1.Controls.Add(myNewTabItem);
The tab control is a collection of tab pages, so you add tab pages like you add any control to a collection. Note that the tabs show up in the order you add them.
If you are trying to add a tab to the form at runtime, probably the issue is that you are trying to adjust the form definition instead of the specific instance of that form that you are currently displaying. When a form is opened, it is an instance of the form definition. You have to find that instance in order to modify its properties. Therefore, you would have to have the other part of your program somehow know about that particular instance of your form through something like a reference variable.

Building C# .NET windows application with multiple views

I'm rewriting an old application and use this as a good opportunity to try out C# and .NET development (I usually do a lot of plug-in stuff in C).
The application is basically a timer collecting data. It has a start view with a button to start the measurement. During the measurement the app has five different views depending on what information the user wants to see.
What is the best practice to switch between the views?
From start to running?
Between the running views?
Ideas:
Use one form and hide and show controls
Use one start form and then a form with a TabControl
Use six separate forms
Creating a bunch of overlaid panels is a design-time nightmare.
I would suggest using a tab control with each "view" on a separate tab, and then picking the correct tab at runtime. You can avoid showing the tab headers by putting something like this in your form's Load event:
tabControl1.Top = tabControl1.Top - tabControl1.ItemSize.Height;
tabControl1.Height = tabControl1.Height + tabControl1.ItemSize.Height;
tabControl1.Region = new Region(new RectangleF(tabPage1.Left, tabPage1.Top, tabPage1.Width, tabPage1.Height + tabControl1.ItemSize.Height));
What I do is to have a Panel where your different views will sit on the main form.
then create user controls for your different views.
Then when I want to switch between a'view' you dock it to Panel on the main form.. code looks a little like this.
i preffer this because you can then reuse your views, like if you want to open up a view in a tab you can dock your user controls inside tab pages.. or even inherit from
tabpage instead of usercontrol to make things a bit more generic
public partial class MainForm : Form
{
public enum FormViews
{
A, B
}
private MyViewA viewA; //user control with view a on it
private MyViewB viewB; //user control with view b on it
private FormViews _formView;
public FormViews FormView
{
get
{
return _formView;
}
set
{
_formView = value;
OnFormViewChanged(_formView);
}
}
protected virtual void OnFormViewChanged(FormViews view)
{
//contentPanel is just a System.Windows.Forms.Panel docked to fill the form
switch (view)
{
case FormViews.A:
if (viewA != null) viewA = new MyViewA();
//extension method, you could use a static function.
this.contentPanel.DockControl(viewA);
break;
case FormViews.B:
if (viewB != null) viewB = new MyViewB();
this.contentPanel.DockControl(viewB);
break;
}
}
public MainForm()
{
InitializeComponent();
FormView = FormViews.A; //simply change views like this
}
}
public static class PanelExtensions
{
public static void DockControl(this Panel thisControl, Control controlToDock)
{
thisControl.Controls.Clear();
thisControl.Controls.Add(controlToDock);
controlToDock.Dock = DockStyle.Fill;
}
}
Tabbed forms are usually good... but only if you want the user to be able to see any view at any time... and it sounds like you might not.
Separate forms definitely works, but you need to make sure that the switch is seemless...if you make sure the new form appears the same exact size and location of the old form, it will look like it thew same for with changing controls.
The method I often use is actually to pre-setup all my controls on individual "Panel" controls and then show and hide these panels as I need them. The "Panel" control is basically a control container... you can move the panel and all controls on it move relative. And if you show or hide the panel, the controls on it do the same. They are great for situations like this.
The method I often use is actually to
pre-setup all my controls on
individual "Panel" controls and then
show and hide these panels as I need
them.
Instead of making each view a panel within a single form you could make each view a UserControl. Then create a single form and write code to create and display the correct UserControl in the Form and to switch from one to the next. This would be easier to maintain because you will have a separate class for each view instead of a single Form class with 6 panels each with their own controls -- that seems difficult and error prone to maintain.
I would also check out Composite Application Guidance for WPF or Smart Client Software Factory

Categories