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c# event handler for multiple dynamically created control

I have a loop that could create 1 or maybe 10 or maybe 584575 (example, not actually true) FlowLayoutPanels. For all these panels I want a hover event handler, or maybe later another type of event handler but for now only hover.
How can I make this happen for multiple same type created controls?
FlowLayoutPanel finalResult_panel = new FlowLayoutPanel{
FlowDirection = FlowDirection.LeftToRight,
BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle,
Name = "result_flowLayoutPanel" + i,
Size = new System.Drawing.Size(790, 72),
TabIndex = i,
};

You can attach the handler like this
finalResult_panel.MouseHover += panel_MouseHover;
private void panel_MouseHover(object sender, EventArgs e)
{
}
Alternatively you can create an anonymous delegate
finalResult_panel_MouseHover += (s,e) => {
//event code
};
These will attach the same handlers to every panel so if you need to differentiate, you can do that in the handler itself (using the sender property) or somehow differentiate before attaching the handler.

Adding actions to programmatically added buttons

I am creating a program where it is required to have a list of buttons which relate to different things on the host computer.
I have achieved this as shown in the code below (example code):
Button btn = new Button();
btn.Name = "Button1";
btn.Text = "Item 1";
this.formLayoutProject.Controls.Add(btn);
This will eventually go into a for loop and more buttons will be on the flow layout, but i am starting small scale and working up so i don't get problems later.
This produces the button as expected (formatting will be done here too but haven't got that far).
What I am stuck on is how would I add a click event/right click event context menu onto the button?
I can put the click events in the code for buttons and items which will be fixed on the form and they work but I don't know how to do this dynamically as the buttons will be different on each target machine.
I have searched on Google but I haven't found what im looking for (probably due to the fact im not sure what the keywords are for the search).
How would I accomplish this?

You can add a button click event handler by using += operator on the event of your new btn object:
// Add 10 buttons dynamically.
// Bind to the same method.
for (var i = 1; i <= 10; i += 1)
{
Button btn = new Button();
btn.Name = "Button" + i;
btn.Text = "Item " + i;
this.formLayoutProject.Controls.Add(btn);
// Add handler.
btn.Click += btn_Click;
}
Now you just need to define the handler method:
private void btn_Click(object sender, EventArgs e)
{
// This is the button which was clicked.
var button = (Button)sender;
var buttonName = button.Name;
// Do some stuff.
// To detect certain mouse click events, cast e as a MouseClick.
MouseEventArgs mouseEvents = (MouseEventArgs)e;
// Now use the mouseEvents object to handle specific events based on the button clicked.
if (mouseEvents.Button == MouseButtons.Right)
{
// Right button clicked.
}
else if (mouseEvents.Button == MouseButtons.Left)
{
// Left button clicked.
}
}

Event handler for a dynamically added button

Code :
public partial class Form3 : Form
{
...
...
private void button1_Click(object sender, EventArgs e)
{
Panel p = new Panel();
TextBox diaryName = new TextBox();
Button b = new Button();
Label l = new Label();
diaryName.Font = new Font("Consolas", 12, FontStyle.Bold);
b.Font = buttonFont;
l.Font = buttonFont;
b.BackColor = Color.Wheat;
l.Text = "Diary Name : ";
b.Text = "Add Diary";
Point lbl = l.Location;
diaryName.Location = new Point(l.Location.X + l.Width + 5, lbl.Y);
Point txtbox = diaryName.Location;
b.Location = new Point(txtbox.X + diaryName.Width + 20, txtbox.Y);
p.Controls.Add(l);
p.Controls.Add(diaryName);
p.Controls.Add(b);
p.Location = new Point(12,272);
p.Size = new Size(20 + 20 + 20 + diaryName.Width + l.Width + b.Width, diaryName.Height);
// I need help here..
// b.Click += new EventHandler(); ???
this.Controls.Add(p);
this.Height += 50;
this.Width += 30;
this.FormBorderStyle = FormBorderStyle.Fixed3D;
}
...
}
The above code adds a panel that contains a label,a textBox and a button to the form , that's all working fine, my problem is that I want to handle click event of the dynamically added button (b) , In my event handling code I should be able to access the dynamically added TextBox (diaryName) for validation purposes, but I don't know how to do It. I tried adding another function within the same class Form3 , but since The textbox t is created within the button1_Click function, I am unable to access the textbox , so How can I get around this ?
I am new to c#, I have a Java background so is there any way in c# to declare event handlers like this
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
System.out.println("You clicked the button");
}
});

You can easy assign a handler to the button's event this way:
b.Click += new EventHandler(newButtonClick);
where
protected void newButtonClick(object sender, EventArgs e)
{
//Access your textbox like this
var myTextBox = this.Controls.OfType<TextBox>().FirstOrDefault(tb=>tb.Name == "diaryName");
if(myTextBox!=null)
{
//rest of your code here
}
}
However it's a poor practice. Your button will depend heavily on the objects created dynamically somewhere outside - that breaks encapsulation rule of OOP. Secondly - did you think what will happen if you'll click your original button (the one you showed your handler for) twice?
edit: When I've come to think about it, your method is not that dynamic really. It creates those controls on the fly, but they're not generic in any way - it's a static piece of code, that creates always the same result. So in this case I'd think about putting your new panel, textbox and button in the form as a public items and then initialize them inside your method.
It'd be even better to create them in the visual studio's designer already, hide them using Visible properties and then in button1_Click you could only change their sizes and show them up.

Ok, need to add event for button click,
1) So after you create new Button
Button b = new Button();
2) next add click event for that
b.Click += new EventHandler(b_Click);
3) and then write the actual function body for click event in your code
void b_Click(object sender, EventArgs e)
{
//Your code for click operation
}

How to add several buttons and their click events dynamically in c# code behind?

Hi I want to add several buttons and their click events dynamically to my windows forms application in my code behind where my buttons will execute System.Diagnostics.Process.Start(targetURL); how can I acheieve this ?

You just need to create the button, set it's properties and event handlers and then add it to the Controls collection on the form.
var button = new Button();
try
{
button.Text = "Button 1";
button.Click += (sender, e) => System.Diagnostics.Process.Start(targetURL);
//Or if you don't want to use a lambda and would rather have a method;
//button.Click += MyButton_Click;
Controls.Add(button);
}
catch
{
button.Dispose();
throw;
}
//Only needed when not using a lambda;
void MyButton_Click(Object sender, EventArgs e)
{
System.Diagnostics.Process.Start(targetURL);
}

Declare your buttons variables.
Add the event handlers
Add them to the form Controls property.
Profit

You can add any control you like to the Controls collection of the form:
var targetURL = // ...
try
{
SuspendLayout();
for (int i = 0; i < 10; i++)
{
var button = new Button();
button.Text = String.Format("Button {0}", i);
button.Location = new Point(0, i * 25);
button.Click += (object sender, EventArgs e) => System.Diagnostics.Process.Start(targetURL);
this.Controls.Add(button);
}
}
finally
{
ResumeLayout();
}
When adding several controls to a parent control, it is recommended that you call the SuspendLayout method before initializing the controls to be added. After adding the controls to the parent control, call the ResumeLayout method. Doing so will increase the performance of applications with many controls.

You could write a user control that contains a textbox "txbURL", a button "btnNavigateToURL" and write the eventhandler of your button, to execute your code (System.Diagnostics.Process.Start(targetURL);)
Once you've done that, it's easy to add your control to your form on runtime, writing some code like this (don't have a c# editor right now, so you may have to verify the code)
MyControlClassName userControl = new MyControlClassName(string targetUrl);
userControl.Parent = yourForm;
yourForm.Controls.Add(userControl);
that's it.

Referring to programmatically created button and it's click event

I'm absolute beginner when it comes to mono for android.
I've used following code snippet to create 50 buttons programmatically:
for(int i=0;i<50;i++)
{
//code to calculate x and y position
btn=new Button(this);
//btn.SetBackgroundColor(Android.Resource.Color.);
btn.SetTextSize(Android.Util.ComplexUnitType.Sp,8);
btn.Text="Scrip "+i+"\n"+"CMP "+i+"\n"+"%Chg "+i;
lp = new RelativeLayout.LayoutParams(new ViewGroup.MarginLayoutParams((width+30)/5, (height-10)/10));
btn.LayoutParameters=lp;
lp.SetMargins(leftMargin,topMargin, 0, 0);
main.AddView(btn);
}
String str="";
btn.Click += (sender, e) =>
{
str=btn.Text;
Toast.MakeText(this, "Selected="+str,ToastLength.Short).Show();
Console.WriteLine("Selected="+str);
};
But one big problem with this code is at the end of the loop, btn object has reference of the last button only.
So if any button other than last button is pressed, button click event is not fired.
How to resolve it?
Ideally, it should return the text of the clicked button.
Also, referring to below screenshot, the default button style doesn't look good here. So I want to change it to exact rectangle and not rounded-rectangel(the default one).
Any idea on this?
As I'm very new to this, any help will be appreciated !!
EDIT
Asa result of your help, I'm able to create and refer all buttons appropriately.
But how to set their style as exact rectangle??

Move btn.Click += (sender, e) subscription inside for loop.
Even better - create one named method instead of creating many anonymous. E.g. Button_Click and subscribe to it:
btn = new Button(this);
btn.Click = Button_Click;
Inside that method you can cast sender object to Button and know which button was clicked.
UPDATE: here is complete code
const int rowsCount = 10;
const int columnsCount = 5;
int buttonsCount = rowsCount * columnsCount;
for (int i = 0; i < buttonsCount; i++)
AddButton();
I prefer not to use magic numbers in code :)
private void AddButton()
{
Button button = new Button(this);
button.Click += Button_Click;
// add text and other properties
main.AddView(button);
}
private void Button_Click(object sender, EventArgs e)
{
Button button = (sender as Button);
// use clicked button e.g. Console.WriteLine("Selected = {0}", button.Text);
}

Your for loop operates on a button and creates a new instance of it every time, but your click event is only added once (it is outside your for loop). Therefore it will only be added to the last instance of Button that is put into btn (the last button from the for loop).
You need to either create each button separately (putting them in a List say) and then outside the for loop you will have a reference to each that you can add the click event to each button individually. Or (the much better way) add the click event inside the for loop, so that each button you create adheres to it. Bear in mind that since the event will then be reached by an arbitrary button(one of your 50) that it will be best to use the sender parameter to determine its text value.
i.e.:
btn.Click += (sender, e) =>
{
Button b = sender as Button;
if ( b == null ) return;
String str;
str=b.Text;
Toast.MakeText(this, "Selected="+str,ToastLength.Short).Show();
Console.WriteLine("Selected="+str);
};

You have created 50 buttons, so you need to have 50 references to it. The easiest way to achieve this is to create an array of buttons, like so:
Button[] btns = new Button[50];
for(int i=0;i<50;i++)
{
{
//code to calculate x and y position
btns[i]=new Button(this);
//btn.SetBackgroundColor(Android.Resource.Color.);
btns[i].SetTextSize(Android.Util.ComplexUnitType.Sp,8);
btns[i].Text="Scrip "+i+"\n"+"CMP "+i+"\n"+"%Chg "+i;
lp = new RelativeLayout.LayoutParams(new ViewGroup.MarginLayoutParams((width+30)/5, (height-10)/10));
btns[i].LayoutParameters=lp;
lp.SetMargins(leftMargin,topMargin, 0, 0);
main.AddView(btn);
}
btns[i].Click += (sender, e) =>
{
String str= ( (sender as Button) != null) ? (sender as Button).Content.ToString() : "";
Toast.MakeText(this, "Selected="+str,ToastLength.Short).Show();
Console.WriteLine("Selected="+str);
}
}
//EDIT: You'll also need to create an eventhandler for each button

it's because you are setting the button click event outside the for loop. put it on the inside so it gets assigned to every button, not just the last one.