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How to dynamically create buttons and to add different event handler?

I created a function that appends buttons in a form. Buttons when clicked supposed to open different files. File paths are in listbox1. I want to add a click event for every button I append. One button should open one file from listbox1.
The part with appending buttons works, but I can't add a different event for each of them only one.
This is my code. It adds the event to every button but only the last one.
PlaySong is a function that plays ".mp3" file. That works.
Can someone help me?
int i = 0;
private void Load_Songs()
{
List<string> url = new List<string>();
url = listBox1.Items.Cast<String>().ToList();
int p = 5;
for (int j = 0; j < listBox1.Items.Count; j++)
{
EventHandler klik = new EventHandler(Playing);
Song_Data titl = new Song_Data(url[j]);
Button n = new Button
{
Text = titl.Title,
Location = new Point(0, p + 20),
Width = ClientRectangle.Width / 3,
FlatStyle = FlatStyle.Flat
};
p += 20;
n.Click += klik;
List_Artist.Controls.Add(n);
i++;
}
}
private void Playing(object sender, EventArgs e)
{
PlaySong(listBox1.Items[i].ToString());
}

You don't need many event handlers, just store the index to the button's Tag in your loop and then use it to find which index you should use to choose from listbox:
Button n = new Button
{
Text = titl.Title,
Location = new Point(0, p + 20),
Width = ClientRectangle.Width / 3,
FlatStyle = FlatStyle.Flat,
Tag = j
};
Then in your handler:
private void Playing(object sender, EventArgs e)
{
int i= (int)((Button)sender).Tag;
PlaySong(listBox1.Items[i].ToString());
}
to use different handler for each button you can use anonymous event handler, but won't solve your problem:
n.Click += (s, ev) =>
{
//code when button clicked
};

C# delete dynamically added textbox and move all other textboxes down

I have really been struggling with this question for a long time.
I add a textbox and a button on tab press . I put text inside the textboxes:
Now, my question, how do I remove the textbox next to the button I click and move all the textboxes down, so I won't get any open space. If I press on the button next to the 7th textbox, I want it to look like this:
here's my code:
private void Form1_Load(object sender, EventArgs e)
{
//creates a textbox(t0) and a button(b0) on load
TextBox t0 = new TextBox();
t0.Name = "t0";
t0.Location = new Point(16, 12);
t0.Width = 200;
t0.PreviewKeyDown += new PreviewKeyDownEventHandler(PreviewKeyDown);
Button b0 = new Button();
b0.TabStop = false;
b0.Text = "x";
b0.Location = new Point(216, 11);
b0.Size = new System.Drawing.Size(20, 22);
b0.Click += new EventHandler(buttonclicked);
panel1.Controls.Add(t0);
panel1.Controls.Add(b0);
}
private new void PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
{
//if I press tab in the last textbox it creates a new textbox(t + amount of textboxes) and button(b + amount of textboxes)
if (e.KeyData == Keys.Tab)
{
int counter2 = 0;
foreach (TextBox box in panel1.Controls.OfType<TextBox>())
{
counter2++;
}
counter2 = counter2 - 1;
string Name = "t" + Convert.ToString(counter2);
counter2++;
foreach (TextBox box in panel1.Controls.OfType<TextBox>())
{
if (Name == box.Name && box.Focused)
{
TextBox t0 = new TextBox();
Button b0 = new Button();
t0.Location = new Point(16, 12 + counter - panel1.VerticalScroll.Value);
t0.Width = 200;
t0.Name = "t" + Convert.ToString(counter2);
t0.PreviewKeyDown += new PreviewKeyDownEventHandler(PreviewKeyDown);
b0.TabStop = false;
b0.Text = "x";
b0.Name = "b" + Convert.ToString(counter2);
b0.Location = new Point(216, 11 + counter - panel1.VerticalScroll.Value);
b0.Size = new System.Drawing.Size(20, 22);
b0.Click += new EventHandler(buttonclicked);
panel1.Controls.Add(t0);
panel1.Controls.Add(b0);
counter = counter + 25;
}
}
}
}
private void buttonclicked(object sender, EventArgs e)
{
//Remove the textbox next to it.
}
Any help is appreciated

I suggest you use a TableLayoutPanel. Set the GrowStyle on the TableLayoutPanel to AddRows or AddColumns and then you can add/remove controls to it and it will resize automatically. Set the height of each row to a number a little bigger than the height of the textbox. Set the column widths to a value so the textbox and the button can fit in them. You need 2 columns in it.
You do not need to set the location of the controls to a static location. They will be handled by the TableLayoutPanel for you.
Here is how you can add new controls to it.
yourTableLayoutPanel.Controls.Add(yourTextbox1, 0 /* Column Index */, 0 /* Row index */);

Dynamically added labels only show one

Ok so I decided to add controls to a panel on form_load based on labels in an array. Below is my code, but no matter how many files I upload through the button listener and reload this form, it only displays one label and nothing more. Why is it only displaying one? I have added a breakpoint and verified that the count does go up to 2, 3, etc.
Code:
public partial class Attachments : Form
{
ArrayList attachmentFiles;
ArrayList attachmentNames;
public Attachments(ArrayList attachments, ArrayList attachmentFileNames)
{
InitializeComponent();
attachmentFiles = attachments;
attachmentNames = attachmentFileNames;
}
private void Attachments_Load(object sender, EventArgs e)
{
ScrollBar vScrollBar1 = new VScrollBar();
vScrollBar1.Dock = DockStyle.Right;
vScrollBar1.Scroll += (sender2, e2) => { pnl_Attachments.VerticalScroll.Value = vScrollBar1.Value; };
pnl_Attachments.Controls.Add(vScrollBar1);
Label fileName;
for (int i = 0; i < attachmentNames.Count; i++)
{
fileName = new Label();
fileName.Text = attachmentNames[i].ToString();
pnl_Attachments.Controls.Add(fileName);
}
}
private void btn_AddAttachment_Click(object sender, EventArgs e)
{
if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
string fileName = openFileDialog1.FileName;
attachmentFiles.Add(fileName);
attachmentNames.Add(Path.GetFileName(fileName));
this.Close();
}
}
}

This is because the labels are all stacking on top of each other. You will need to specify a top for each one or use an auto-flow panel.
Adding the following line after creating the new label will ensure all labels are visible (you may have to adjust the multiplier depending on your font):
fileName.Top = (i + 1) * 22;

As competent_tech stated the labels are stacking on top of each other, but another approach is to modify the location value of the label.The benefit to this is you can control the absolute location of the label.
fileName.Location = new Point(x, y);
y += marginAmount;
x is the vertical position on the form and y is the horizontal location on the form. Then all that has to be modified is the amount of space you want in between each label in the marginAmount variable.
So in this for loop
for (int i = 0; i < attachmentNames.Count; i++)
{
fileName = new Label();
fileName.Text = attachmentNames[i].ToString();
pnl_Attachments.Controls.Add(fileName);
}
You could modify it to this:
for (int i = 0; i < attachmentNames.Count; i++)
{
fileName = new Label();
fileName.Text = attachmentNames[i].ToString();
fileName.Location = new Point(x, y);
y += marginAmount;
pnl_Attachments.Controls.Add(fileName);
}
Then all you have to do is define x, y, and the marginAmount.

How to create many labels and textboxes dynamically depending on the value of an integer variable?

Is there any way to dynamically create and display 'n' Labels with 'n' corresponding Textboxs when we know value of 'n' after for example, clicking "Display" button.
Let me know if anything make you don't understand my question. Thank you!
I am working with VS C# Express 2010 Windows Form.

I would create a user control which holds a Label and a Text Box in it and simply create instances of that user control 'n' times. If you want to know a better way to do it and use properties to get access to the values of Label and Text Box from the user control, please let me know.
Simple way to do it would be:
int n = 4; // Or whatever value - n has to be global so that the event handler can access it
private void btnDisplay_Click(object sender, EventArgs e)
{
TextBox[] textBoxes = new TextBox[n];
Label[] labels = new Label[n];
for (int i = 0; i < n; i++)
{
textBoxes[i] = new TextBox();
// Here you can modify the value of the textbox which is at textBoxes[i]
labels[i] = new Label();
// Here you can modify the value of the label which is at labels[i]
}
// This adds the controls to the form (you will need to specify thier co-ordinates etc. first)
for (int i = 0; i < n; i++)
{
this.Controls.Add(textBoxes[i]);
this.Controls.Add(labels[i]);
}
}
The code above assumes that you have a button btnDisplay and it has a onClick event assigned to btnDisplay_Click event handler. You also need to know the value of n and need a way of figuring out where to place all controls. Controls should have a width and height specified as well.
To do it using a User Control simply do this.
Okay, first of all go and create a new user control and put a text box and label in it.
Lets say they are called txtSomeTextBox and lblSomeLabel. In the code behind add this code:
public string GetTextBoxValue()
{
return this.txtSomeTextBox.Text;
}
public string GetLabelValue()
{
return this.lblSomeLabel.Text;
}
public void SetTextBoxValue(string newText)
{
this.txtSomeTextBox.Text = newText;
}
public void SetLabelValue(string newText)
{
this.lblSomeLabel.Text = newText;
}
Now the code to generate the user control will look like this (MyUserControl is the name you have give to your user control):
private void btnDisplay_Click(object sender, EventArgs e)
{
MyUserControl[] controls = new MyUserControl[n];
for (int i = 0; i < n; i++)
{
controls[i] = new MyUserControl();
controls[i].setTextBoxValue("some value to display in text");
controls[i].setLabelValue("some value to display in label");
// Now if you write controls[i].getTextBoxValue() it will return "some value to display in text" and controls[i].getLabelValue() will return "some value to display in label". These value will also be displayed in the user control.
}
// This adds the controls to the form (you will need to specify thier co-ordinates etc. first)
for (int i = 0; i < n; i++)
{
this.Controls.Add(controls[i]);
}
}
Of course you can create more methods in the usercontrol to access properties and set them. Or simply if you have to access a lot, just put in these two variables and you can access the textbox and label directly:
public TextBox myTextBox;
public Label myLabel;
In the constructor of the user control do this:
myTextBox = this.txtSomeTextBox;
myLabel = this.lblSomeLabel;
Then in your program if you want to modify the text value of either just do this.
control[i].myTextBox.Text = "some random text"; // Same applies to myLabel
Hope it helped :)

Here is a simple example that should let you keep going add somethink that would act as a placeholder to your winform can be TableLayoutPanel
and then just add controls to it
for ( int i = 0; i < COUNT; i++ ) {
Label lblTitle = new Label();
lblTitle.Text = i+"Your Text";
youlayOut.Controls.Add( lblTitle, 0, i );
TextBox txtValue = new TextBox();
youlayOut.Controls.Add( txtValue, 2, i );
}

Suppose you have a button that when pressed sets n to 5, you could then generate labels and textboxes on your form like so.
var n = 5;
for (int i = 0; i < n; i++)
{
//Create label
Label label = new Label();
label.Text = String.Format("Label {0}", i);
//Position label on screen
label.Left = 10;
label.Top = (i + 1) * 20;
//Create textbox
TextBox textBox = new TextBox();
//Position textbox on screen
textBox.Left = 120;
textBox.Top = (i + 1) * 20;
//Add controls to form
this.Controls.Add(label);
this.Controls.Add(textBox);
}
This will not only add them to the form but position them decently as well.

You can try this:
int cleft = 1;
intaleft = 1;
private void button2_Click(object sender, EventArgs e)
{
TextBox txt = new TextBox();
this.Controls.Add(txt);
txt.Top = cleft * 40;
txt.Size = new Size(200, 16);
txt.Left = 150;
cleft = cleft + 1;
Label lbl = new Label();
this.Controls.Add(lbl);
lbl.Top = aleft * 40;
lbl.Size = new Size(100, 16);
lbl.ForeColor = Color.Blue;
lbl.Text = "BoxNo/CardNo";
lbl.Left = 70;
aleft = aleft + 1;
return;
}
private void btd_Click(object sender, EventArgs e)
{
//Here you Delete Text Box One By One(int ix for Text Box)
for (int ix = this.Controls.Count - 2; ix >= 0; ix--)
//Here you Delete Lable One By One(int ix for Lable)
for (int x = this.Controls.Count - 2; x >= 0; x--)
{
if (this.Controls[ix] is TextBox)
this.Controls[ix].Dispose();
if (this.Controls[x] is Label)
this.Controls[x].Dispose();
return;
}
}

How to add buttons dynamically to my form?

I want to create 10 buttons on my form when I click on button1. No error with this code below but it doesnt work either.
private void button1_Click(object sender, EventArgs e)
{
List<Button> buttons = new List<Button>();
for (int i = 0; i < buttons.Capacity; i++)
{
this.Controls.Add(buttons[i]);
}
}

You aren't creating any buttons, you just have an empty list.
You can forget the list and just create the buttons in the loop.
private void button1_Click(object sender, EventArgs e)
{
int top = 50;
int left = 100;
for (int i = 0; i < 10; i++)
{
Button button = new Button();
button.Left = left;
button.Top = top;
this.Controls.Add(button);
top += button.Height + 2;
}
}

It doesn't work because the list is empty. Try this:
private void button1_Click(object sender, EventArgs e)
{
List<Button> buttons = new List<Button>();
for (int i = 0; i < 10; i++)
{
Button newButton = new Button();
buttons.Add(newButton);
this.Controls.Add(newButton);
}
}

You could do something like this:
Point newLoc = new Point(5,5); // Set whatever you want for initial location
for(int i=0; i < 10; ++i)
{
Button b = new Button();
b.Size = new Size(10, 50);
b.Location = newLoc;
newLoc.Offset(0, b.Height + 5);
Controls.Add(b);
}
If you want them to layout in any sort of reasonable fashion it would be better to add them to one of the layout panels (i.e. FlowLayoutPanel) or to align them yourself.

Two problems- List is empty. You need to add some buttons to the list first. Second problem: You can't add buttons to "this". "This" is not referencing what you think, I think. Change this to reference a Panel for instance.
//Assume you have on your .aspx page:
<asp:Panel ID="Panel_Controls" runat="server"></asp:Panel>
private void button1_Click(object sender, EventArgs e)
{
List<Button> buttons = new List<Button>();
for (int i = 0; i < buttons.Capacity; i++)
{
Panel_Controls.Controls.Add(buttons[i]);
}
}

use button array like this.it will create 3 dynamic buttons bcoz h variable has value of 3
private void button1_Click(object sender, EventArgs e)
{
int h =3;
Button[] buttonArray = new Button[8];
for (int i = 0; i <= h-1; i++)
{
buttonArray[i] = new Button();
buttonArray[i].Size = new Size(20, 43);
buttonArray[i].Name= ""+i+"";
buttonArray[i].Click += button_Click;//function
buttonArray[i].Location = new Point(40, 20 + (i * 20));
panel1.Controls.Add(buttonArray[i]);
} }

I had the same doubt and came up with the following contribution:
int height = this.Size.Height;
int width = this.Size.Width;
int widthOffset = 10;
int heightOffset = 10;
int btnWidth = 100; // Button Widht
int btnHeight = 40; // Button Height
for (int i = 0; i < 50; ++i)
{
if ((widthOffset + btnWidth) >= width)
{
widthOffset = 10;
heightOffset = heightOffset + btnHeight
var button = new Button();
button.Size = new Size(btnWidth, btnHeight);
button.Name = "" + i + "";
button.Text = "" + i + "";
//button.Click += button_Click; // Button Click Event
button.Location = new Point(widthOffset, heightOffset);
Controls.Add(button);
widthOffset = widthOffset + (btnWidth);
}
else
{
var button = new Button();
button.Size = new Size(btnWidth, btnHeight);
button.Name = "" + i + "";
button.Text = "" + i + "";
//button.Click += button_Click; // Button Click Event
button.Location = new Point(widthOffset, heightOffset);
Controls.Add(button);
widthOffset = widthOffset + (btnWidth);
}
}
Expected Behaviour:
This will generate the buttons dinamically and using the current window size, "break a line" when the button exceeds the right margin of your window.

First, you aren't actually creating 10 buttons. Second, you need to set the location of each button, or they will appear on top of each other. This will do the trick:
for (int i = 0; i < 10; ++i)
{
var button = new Button();
button.Location = new Point(button.Width * i + 4, 0);
Controls.Add(button);
}

You can't add a Button to an empty list without creating a new instance of that Button.
You are missing the
Button newButton = new Button();
in your code plus get rid of the .Capacity