We Keep Coding

C# - How to find out which dynamic button was clicked?

I am writing a program where I dynamically add buttons, I do that by storing them in a Dictionary to get a certain value from them later on (the color of the background).
I need to set a Click event on every one of them, but every Click event has to be a little different, as by clicking the button, a ColorDialog pops up and changes the background of the button.
Is there a way to know which button I clicked? In the following code, the button1 click event adds the other buttons and sets the EventHandler for each of them, what should be the code for the EventHandler? Thank you so much in advance guys.
int i = 0;
Dictionary<int, Button> buttonDictionary = new Dictionary<int, Button>();
Dictionary<int, ColorDialog> colorsDictionary = new Dictionary<int ColorDialog>();
public void button1_Click(object sender, EventArgs e)
{
i++;
buttonDictionary.Add(i, new Button());
buttonDictionary[i].Click += new EventHandler(Click);
this.Controls.Add(buttonDictionary[i]);
}
public void Click(object sender, EventArgs e)
{
//Somehow get the int key of the button that was clicked???? (in this case: int j)
int j;
if (!colorsDictionary.ContainsKey(j))
{
colorsDictionary.Add(j, new ColorDialog());
}
if (colorsDictionary[j].ShowDialog() == DialogResult.OK)
{
buttonDictionary[j].BackColor = colorsDictionary[j].Color;
}
}
The code is made just for adding the buttons, I will be glad for any kind of help, thank you guys!

Well, a direct answer to your question is: cast the sender to a Button
Button pressedButton = (Button) sender;
and then check to which button of the dictionary it matches:
foreach (var entry in buttonDictionary)
{
if (entry.Value == pressedButton)
{
j = entry.Key;
break;
}
}
However, that's overly complex for what you want to achieve. It would be much easier if you had a direct relationship between the button and the color picker:
Dictionary<Button, ColorDialog> buttonDictionary = new Dictionary<Button, ColorDialog>();
Then fill it like this:
public void button1_Click(object sender, EventArgs e)
{
i++;
var button = new Button();
this.Controls.Add(button);
button.Click += new EventHandler(Click);
buttonDictionary.Add(button, null);
}
And later access it with
public void Click(object sender, EventArgs e)
{
Button pressedButton = (Button) sender;
ColorDialog dialog = buttonDictionary[pressedButton];
if (dialog == null)
{
dialog = new ColorDialog();
buttonDictionary[pressedButton] = dialog;
}
if (dialog.ShowDialog() == DialogResult.OK)
{
pressedButton.BackColor = dialog.Color;
}
}
Even more, the question is why you would need so many ColorDialgos, since it should be possible with one dialog only. You can get rid of i, j, all dictionaries and most handling as well. IMHO, the following should be sufficient:
public void button1_Click(object sender, EventArgs e)
{
var button = new Button();
Controls.Add(button);
button.Click += Click;
}
public void Click(object sender, EventArgs e)
{
Button pressedButton = (Button) sender;
ColorDialog dialog = new ColorDialog {Color = pressedButton.BackColor};
if (dialog.ShowDialog() == DialogResult.OK)
{
pressedButton.BackColor = dialog.Color;
}
}
Bonus info:
I don't exactly know what you want to achieve. But your buttons will all be in the same place, overlapping each other. To avoid this, drag a flow layout panel onto the form and then add the buttons to the flow layout:
flowLayoutPanel1.Controls.Add(button);
This will ensure that your buttons are nicely arranged.

How to create and call dynamically instantiated methods in C#? [duplicate]

I am creating one button on a page dynamically. Now I want to use the button click event on that button.
How can I do this in C# ASP.NET?

Button button = new Button();
button.Click += (s,e) => { your code; };
//button.Click += new EventHandler(button_Click);
container.Controls.Add(button);
//protected void button_Click (object sender, EventArgs e) { }

The easier one for newbies:
Button button = new Button();
button.Click += new EventHandler(button_Click);
protected void button_Click (object sender, EventArgs e)
{
Button button = sender as Button;
// identify which button was clicked and perform necessary actions
}

Simply add the eventhandler to the button when creating it.
button.Click += new EventHandler(this.button_Click);
void button_Click(object sender, System.EventArgs e)
{
//your stuff...
}

It is much easier to do:
Button button = new Button();
button.Click += delegate
{
// Your code
};

You can create button in a simple way, such as:
Button button = new Button();
button.Click += new EventHandler(button_Click);
protected void button_Click (object sender, EventArgs e)
{
Button button = sender as Button;
// identify which button was clicked and perform necessary actions
}
But event probably will not fire, because the element/elements must be recreated at every postback or you will lose the event handler.
I tried this solution that verify that ViewState is already Generated and recreate elements at every postback,
for example, imagine you create your button on an event click:
protected void Button_Click(object sender, EventArgs e)
{
if (Convert.ToString(ViewState["Generated"]) != "true")
{
CreateDynamicElements();
}
}
on postback, for example on page load, you should do this:
protected void Page_Load(object sender, EventArgs e)
{
if (Convert.ToString(ViewState["Generated"]) == "true") {
CreateDynamicElements();
}
}
In CreateDynamicElements() you can put all the elements you need, such as your button.
This worked very well for me.
public void CreateDynamicElements(){
Button button = new Button();
button.Click += new EventHandler(button_Click);
}

Let's say you have 25 objects and want one process to handle any one objects click event. You could write 25 delegates or use a loop to handle the click event.
public form1()
{
foreach (Panel pl in Container.Components)
{
pl.Click += Panel_Click;
}
}
private void Panel_Click(object sender, EventArgs e)
{
// Process the panel clicks here
int index = Panels.FindIndex(a => a == sender);
...
}

How to design a keypad in C#?

I am new to C# and I am planing to design my own keypad but I don't know how/where to start. as shown in photo, I have 4 textBoxes the keypad buttons.
The first problem came into my mind was: how can I detect the cursor location (which textBox is the cursor in?).
So for example if I had only one textbox then it is easy I could write inside button1 : textBox1.text = "1" and inside button2 : textBox1.text = "2" and inside button_A : textBox1.text = "A".... and so on but I have 4 textBoxes and it is confusing.
Can you please provide me with an idea or what to write inside each button to print its value in the textbox which the cursor is in.
Thank you professionals.

Firstly, have a textbox that represents the one that is selected (outside of subroutines but inside the class):
TextBox SelectedTextBox = null;
And then make the "Click" event of each TextBox look like this:
private void textBoxNUM_Click(object sender, EventArgs e)
{
SelectedTextBox = sender as TextBox;
}
And then make the "Click" event of each Button look like this:
private void buttonNUM_Click(object sender, EventArgs e)
{
if (SelectedTextBox != null)
{
SelectedTextBox.Text = buttonNUM.Text;//Or set it to the actual value, whatever.
}
}
Or if that one doesn't work, this should.
private void buttonNUM_Click(object sender, EventArgs e)
{
if (SelectedTextBox != null)
{
(SelectedTextBox as TextBox).Text = buttonNUM.Text;//Or set it to the actual value, whatever.
}
}

To check if a textbox is focused you can do
if(textbox1.Focused)
{
//Print the value of the button to textbox 1
}
else if (textbox2.Focused)
{
//Print the value to textbox 2
}
UPDATE:
Since the textbox will lose focus when you click the button, you should have a temporary textbox (ie lastTextboxThatWasFocused) which is saved to everytime a textbox gains focus. Write an OnFocused Method and do something like
public void Textbox1OnFocused(/*Sender Event Args*/)
{
lastTextboxThatWasFocused=textbox1;
}
Then on button click you can do
if(lastTextboxThatWasFocused.Equals(textbox1))
{
//ETC.
}

You can give something along these lines a try. Create a generic click handler for the buttons and then assign the value to a textbox the text from the button, which happens to be the value. You can check which box was the last one focused in the TextBoxes' Click event. Create a global variable to store which one and use it in the below method.
private TextBox SelectedTextBox { get; set; }
private void NumericButton_Click(object sender, EventArgs e)
{
var clickedBox = sender as Button;
if (clickedBox != null)
{
this.SelectedTextBox.Text += clickedBox.Text;
}
}
private void TextBox_Click(object sender, EventArgs e)
{
var thisBox = sender as TextBox;
if (thisBox == null)
{
return;
}
this.SelectedTextBox = thisBox;
}

Try this code:
TextBox LastTxtBox;
private void textBox_Enter(object sender, EventArgs e)
{
LastTxtBox = sender as TextBox;
}
private void button_Click(object sender, EventArgs e)
{
LastTxtBox.Text = this.ActiveControl.Text;
}
Add textBox_Enter function to all textboxes enter event.
Add button_Click to all buttons click event.

Button Enter Event
Control _activeControl;
private void NumberPadButton_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
if (_activeControl is TextBox || _activeControl is RichTextBox)
{
_activeControl.Text += btn.Text;
if (!_activeControl.Focused) _activeControl.Focus();
}
}
TextBox or RihTextBox Enter Event
private void TextBoxEnter_Click(object sender, EventArgs e)
{
_activeControl = (Control)sender;
}

how to create events on dynamic `textboxes`

I managed to create textboxes that are created at runtime on every button click. I want the text from textboxes to disappear when I click on them. I know how to create events, but not for dynamically created textboxes.
How would I wire this up to my new textboxes?
private void buttonClear_Text(object sender, EventArgs e)
{
myText.Text = "";
}

This is how you assign the event handler for every newly created textbox :
myTextbox.Click += new System.EventHandler(buttonClear_Text);

The sender parameter here should be the textbox which sent the even you will need to cast it to the correct control type and set the text as normal
if (sender is TextBox) {
((TextBox)sender).Text = "";
}
To register the event to the textbox
myText.Click += new System.EventHandler(buttonClear_Text);

Your question isn't very clear, but I suspect you just need to use the sender parameter:
private void buttonClear_Text(object sender, EventArgs e)
{
TextBox textBox = (TextBox) sender;
textBox.Text = "";
}
(The name of the method isn't particularly clear here, but as the question isn't either, I wasn't able to suggest a better one...)

when you create the textBoxObj:
RoutedEventHandler reh = new RoutedEventHandler(buttonClear_Text);
textBoxObj.Click += reh;
and I think (not 100% sure) you have to change the listener to
private void buttonClear_Text(object sender, RoutedEventArgs e)
{
...
}

I guess the OP wants to clear all the text from the created textBoxes
private void buttonClear_Text(object sender, EventArgs e)
{
ClearSpace(this);
}
public static void ClearSpace(Control control)
{
foreach (var c in control.Controls.OfType<TextBox>())
{
(c).Clear();
if (c.HasChildren)
ClearSpace(c);
}
}

This should do the job :
private void button2_Click(object sender, EventArgs e)
{
Button btn = new Button();
this.Controls.Add(btn);
// adtionally set the button location & position
//register the click handler
btn.Click += OnClickOfDynamicButton;
}
private void OnClickOfDynamicButton(object sender, EventArgs eventArgs)
{
//since you dont not need to know which of the created button is click, you just need the text to be ""
((Button) sender).Text = string.Empty;
}

Dynamicly added Controls [e.g Button] : How to add events and Access

At my program i dynamicly add Buttons to my form
{
...
Button bt = new Button();
bt.Text = "bla bla";
bt.MouseClick += new MouseEventHandler(bt_MouseClick);
myPanel.Controls.Add(bt);
...
}
void bt_MouseClick(object sender, MouseEventArgs e)
{
TabPage _tab = new TabPage();
_tab.Text = ??? // I want to get the Button's text ! this.Text returns me the
//main form.Text
}
How can access my dynamic Buttons properties ? How can I understand whick button is
clicked either getting its text.
Thanks.

void bt_MouseClick(object sender, MouseEventArgs e)
{
TabPage _tab = new TabPage();
_tab.Text = ((Button)sender).Text;
}

When an EventHandler delegate is invoked, the sender parameter is the component that raised the event, and the e parameter is a subclass of EventArgs that provides any additional component/event specific information for the event.
Therefore you can establish which button the event fired on by casting the sender parameter to Button:
void bt_MouseClick(object sender, MouseEventArgs e)
{
var button = (Button)sender;
TabPage _tab = new TabPage();
_tab.Text = button.Text;
}