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button in c# not firing

I am writing a simple code it has 3 buttons 2 that will need to open up other forms and one to close the program. When i start the program the exit button will not work even though i have it coded the same as any other time i have wrote a program.
When i press any of the buttons nothing happens. Im not 100% sure how to use the buttons to open another form but i know the exit button should work as is.
Here is the code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace _3343_ParksJ_Lab02
{
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}
private void workerButton_Click(object sender, EventArgs e)
{
WorkerForm workersForum = new WorkerForm();
}
private void suppervisorButton_Click(object sender, EventArgs e)
{
SupervisorForm workersForum = new SupervisorForm();
}
private void exitButton_Click(object sender, EventArgs e)
{
this.Close();
}
}
}

You have to subscribe your buttons' click events to the event methods before they'll fire correctly.
You can check the Designer.cs file to see if this has already been done, though I'm guessing it hasn't. You'll be looking for something like this:
this.workerButton.Click += new System.EventHandler(this.workerButton_Click);
One way to do so is directly in the constructor:
public MainForm()
{
InitializeComponent();
workerButton.Click += workerButton_Click;
suppervisorButton.Click += suppervisorButton_Click;
exitButton.Click += exitButton_Click;
}
Normally, I'd do this through the designer. Select each Button in turn, then open the properties panel and double-click on the event you wish to subscribe to, which will create the corresponding event method in the code-behind for you.

Look at .Designer.cs file and make sure your button is adding the correct delegate method. In your case it should exitButton_Click.
Sometimes when you change names of a button VS designer does not make the name change correctly in the .Designer file. Very rare but it happens.

How can I make a menu for notifyicon?

So.. i've googled around and everywhere i've seen different ways of creating this..
But so far, i haven't managed to make a single working menu.
So i wanted to ask, how does one create a notifyIcon menu?.. (prefered explained in details, as i'm rather new to this)
which way would be best and which should i use.. (so far people seemed to like contextmenu overally, but all i can find is contextmenustrip, not sure if it's the same.)
Currently i got a form, set to visible = false, windowstate minimized, showintaskbar = false.
that's about all it is for now. i wanted to have the menu before going wider.
Thank you for your time and effort for this (not sure if it's formulated properly)
EDIT: i've seemed to manage to make a menu, but how would i make it "appear" on my notify icon, it's a ContextMenu o_o

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace TrayTest.events
{
public partial class TrayMenu : Form
{
public TrayMenu()
{
InitializeComponent();
TrayMenuContext();
}
private void TrayMenuContext()
{
this.notify_icon.ContextMenuStrip = new System.Windows.Forms.ContextMenuStrip();
this.notify_icon.ContextMenuStrip.Items.Add("Test1", null, this.MenuTest1_Click);
this.notify_icon.ContextMenuStrip.Items.Add("Test2", null, this.MenuTest2_Click);
this.notify_icon.ContextMenuStrip.Items.Add("Exit", null, this.MenuExit_Click);
}
void MenuTest1_Click(object sender, EventArgs e)
{
Application.Exit();
}
void MenuTest2_Click(object sender, EventArgs e)
{
Application.Exit();
}
void MenuExit_Click(object sender, EventArgs e)
{
Application.Exit();
}
}
}
This worked fine for me. So i'll just leave it here, for other to take a peak at it.. (this is my Form1, just made 1 with a different name, and it's inside a folder named events (kinda why it has that .events))

"EDIT: i've seemed to manage to make a menu, but how would i make it "appear" on my notify icon, it's a ContextMenu o_o"
I believe you can only assign a ContextMenuStrip to the NotifyIcon using the IDE. For a ContextMenu, you'd have to wire it up via code. Double click your Form to get the Load() event, and wire it up in there:
private void Form1_Load(object sender, EventArgs e)
{
notifyIcon1.ContextMenu = contextMenu1;
}

notifyIcon1->ContextMenu = gcnew System::Windows::Forms::ContextMenu();
System::Windows::Forms::MenuItem^ nI_Open_Item = gcnew System::Windows::Forms::MenuItem("Open");
System::Windows::Forms::MenuItem^ nII_Close_item = gcnew System::Windows::Forms::MenuItem("Close");
notifyIcon1->ContextMenuStrip->Items->Add(status_Item);
notifyIcon1->ContextMenu->MenuItems->Add(nI_Open_Item);

How to create objects dynamically with arbitrary names?

So here's my situation. I am designing a program that requires new Image objects to be created in real-time on a Canvas, when the user clicks a certain Button. Seeing as I don't know exactly how many of said Images any given user will create, I can't assign names in the code for each and every one of them. The Images need to be named "Image0", "Image1", "Image2", etc, depending on how many Images already exist on the page. Kinda like how Visual Studio itself works, where each time you drop a control onto the design view, it automatically appends a number to the name of the control.
Does anyone have a code snippet capable of performing this function?

You don't have to explicitly name all controls. Just add them to the canvas "controls" list.
Create a windows app with a single button and a flowLayoutPanel.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication6
{
public partial class Form1 : Form
{
int i = 1;
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
var button = new Button { Text = string.Format("Button {0}", i) };
button.Click += new EventHandler(button_Click);
flowLayoutPanel1.Controls.Add(button);
i += 1;
}
void button_Click(object sender, EventArgs e)
{
Button button = (Button)sender;
button.Text = " clicked!";
}
}
}

I don't have a direct answer to your question, but from the sounds of it, and I could be wrong because I don't know what you're trying to do, you're viewing the problem from a newbie programmer perspective. You might want to consider using a collection of some kind (perhaps a list) and dynamically adding image objects to that. If you want a string name associated with each object, you could consider a dictionary of type Dictionary<string,Image>

c# main menu and mdi forms

So far in my life, as a .net developer, I have made heavy use of mdi forms to display particular "menu points" such as for instance "module 1" "module 2" and so on.
I have been doing this the following way:
create a parent form with "isMdiContainer" set to "true"
create a menu strip in in the mdi container
create a child form implementing singleton in order for the form to be shown only once
Add something like the following code to the mdi container:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Myapp
{
public partial class MdiContainer : Form
{
private module1 Module1Window;
private module2 Module2Window;
private module3 Module3Window;
public FormContainer()
{
InitializeComponent();
this.Module1Window = modul1.getInstance();
this.Module1Window.MdiParent = this;
this.Module2Window = modul2.getInstance();
this.Module2Window.MdiParent = this;
this.Module3Window = modul3.getInstance();
this.Module3Window.MdiParent = this;
this.Module1Window.Show();
}
private void module1ToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Module3Window.Hide();
this.Module2Window.Hide();
this.Module1Window.Show();
}
private void module2ToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Module1Window.Hide();
this.Module3Window.Hide();
this.Module2Window.Show();
}
private void module3ToolStripMenuItem_Click(object sender, EventArgs e)
{
this.Module1Window.Hide();
this.Module2Window.Hide();
this.Module3Window.Show();
}
}
}
Now, this obviously works fine. But it is a a pain to maintain. Everytime I want to add another child form I have to:
implement Singleton
create the corresponding property in the mdi container
get the instance and set the mdi parent
Hide the new form when other buttons are clicked
Show the form and hide all other Forms when the corresponding button is clicked
Whats a more elegant or lets say efficient approach to archive this?

When do you create the menu items? Are these dynamically created along with the child forms?
If so what you can do is create the form and add it to a list and assign the menu item's Tag property to the form. Assign all the menu items click event to the same handler and within the handler do this...
private void menuStrip_Click(object sender, EventArgs e)
{
var menu = (ToolStripItem)sender;
var viewForm = (Form)sender.Tag;
foreach(Form childForm in _childForms)
childForm.Hide();
viewForm.Show();
}
This same handler can be used no matter how many forms you have.
Alternatively you can have a key as the Tag and have a Dictionary<string, Form> so you can more lazily create the forms, however the concept is the same.

How to find previous active control c#

i am developing keyboard control, very simple embedded on a form. using sendkey class to perform char entry. to make this functional is required to know previous selected control.

Something like the following should do the trick:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace DragDropTest
{
public partial class LostFocusTestForm : Form
{
private Control _lastControl;
public LostFocusTestForm()
{
InitializeComponent();
TrapLostFocusOnChildControls(this.Controls);
}
private void finalTextBox_Enter(object sender, EventArgs e)
{
MessageBox.Show("From " + _lastControl.Name + " to " + this.ActiveControl.Name);
}
private void AllLostFocus(object sender, EventArgs e)
{
_lastControl = (Control)sender;
}
private void TrapLostFocusOnChildControls(Control.ControlCollection controls)
{
foreach (Control control in controls)
{
control.LostFocus += new EventHandler(AllLostFocus);
Control.ControlCollection childControls = control.Controls;
if (childControls != null)
TrapLostFocusOnChildControls(childControls);
}
}
}
}

Expanding on David's answer. This is how you can use the Enter event and a variable to store the last control:
using System;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
Control lastControlEntered = null;
public Form1()
{
InitializeComponent();
foreach (Control c in Controls)
if (!(c is Button)) c.Enter += new EventHandler(c_Enter);
}
void c_Enter(object sender, EventArgs e)
{
if (sender is Control)
lastControlEntered = (Control)sender;
}
private void button1_Click(object sender, EventArgs e)
{
label1.Text = lastControlEntered == null ? "No last control" : lastControlEntered.Name;
}
}
}
To run this code, add a few textboxes and other control to a Form in Visual Studio, and add a button and a label and attach the button's click handler to button1_Click. When you press the button, the last control you were in before pressing the button is displayed in the label. Edit this code to suit your needs.

You need to store it in a variable. For Control objects, there's "Enter" event

Another strategy is to use an Extension Method to extend Control.ControlCollection, and then using some indirection (a delegate) recursively parse the Controls collection of the Form adding a special "Enter" handler that updates a static variable. By keeping track of the previous Active Control and the current Active Control, you then have what you need ... if I understand your question fully. Here's an example that requires FrameWork 3.5 or 4.0.
// in a Public static class :
using System;
using System.Collections.Generic;
using System.Windows.Forms;
private static EventHandler _event;
// extension method on Control.ControlCollection
public static void SetEnterEvent(this Control.ControlCollection theCollection, EventHandler theEvent)
{
_event = theEvent;
recurseSetEnter(theCollection);
}
// recurse all the controls and add the Enter Event :
public static void recurseSetEnter(Control.ControlCollection aCollection)
{
foreach (Control theControl in aCollection)
{
// "weed out" things like internal controls of the NumericUpDown Control
// String.IsNullOrWhiteSpace is FrameWork 4.0
// use Trim() followed by String.IsNullOrEmpty for FrameWork 3.5
if (!String.IsNullOrWhiteSpace(theControl.Name))
{
Console.WriteLine("setting enter handler for : " + theControl.Name + " : " + theControl.GetType().ToString());
theControl.Enter += _event;
}
if (theControl.Controls.Count > 0) recurseSetEnter((Control.ControlCollection)theControl.Controls);
}
}
So how do we use this : in a Form :
First let's define an actual Event handler that is going to actually execute when the Enter event is encountered on any control :
We'll keep the current active control, and the previous active control, in public static variables :
public static Control theActiveControl = null;
public static Control thePreviousControl = null;
And here's the code that does the updating :
private void control_enter(object sender, EventArgs e)
{
thePreviousControl = theActiveControl;
theActiveControl = sender as Control;
Console.WriteLine("Active Control is now : " + theActiveControl.Name);
}
Now in the Form_Load event or elsewhere we just need to wire-up the events :
// in a Form**
// define a delegate for the enter Event
private event EventHandler enter = delegate { };
// in the form load even or somewhere : assign an actual event handler to the delegate
enter += new EventHandler(control_enter);
Finally we invoke the extension method on the Controls Collection of the Form :
this.Controls.SetEnterEvent(enter);
Discussion : a WinForm maintains an 'ActiveControl collection : this will contain a pointer to the most recently activated control no matter how deeply nested it is in one or more containers : ... some containers (like Panels) do not register as active controls in this collection even though they have Leave/Enter events ... controls are going to become the ActiveControl when they are used/selected/entered-into/focused-on, etc. Unfortunately there's no "ActiveControlChanged" event.
[edit] in practice I am developing this using"filters" so I can selectively skip over certain object types, or, for example, look for some "key" (in the control name or its tag) to determine whether or not to add the handler ... yes ... it's an experiment. [edit]
[edit] note that some controls like PictureBox expose no 'Enter event, but this code does not cause an error : my long-range goal is to find a way to test, without reflection, whether a particular control does expose a given 'event before I install one : since I consider it bad practice to just let things like PictureBox "wiggle through." So far I have not found the right "test" for "container-ness" ("is ControlContainer" turned out to be the wrong track). You may note also that Panels, for example, expose an 'Enter event, but it's only fired when some Control inside the Panel is activated. [edit]
Hope this is helpful. I am sure this could probably be written more elegantly using Lambdas, but as yet I am a "larva" feeding on the leaves of Skeet in that regard :)

You can do this by
string activeControl= this.ActiveControl.Name

You have to track this yourself. Write a trivial UIElement.LostFocus handler which puts the sender into a "last control with focus" variable, and you're done.
NOTE: WPF. Not sure if you're doing that or WinForms. I've been doing so much WPF lately I have it on the brain.