We Keep Coding

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# How to put RadioButton inside Panel

I have searched everywhere, but the procedure are so painful. How to put multiple RadioButton into a panel programatically without using toolbox. I'm using WinForms. After several suggestion/s, I still can't add the radiobuttons inside the panel.
public partial class Form1 : Form
{
RadioButton[] RadioButton_WallFirstStorey_Yes = new RadioButton[100];
RadioButton[] RadioButton_WallFirstStorey_No = new RadioButton[100];
Panel[] Panel_WallFirstStorey = new Panel[100];
int CheckBoxWidth = 100;
public Form1()
{
InitializeComponent();
//code
//procedure
}
private void InitializeRadioButton_Wall(RadioButton RadioButtonX)
{
RadioButtonX.AutoSize = true;
RadioButtonX.Font = SystemFonts.DefaultFont;
RadioButtonX.BackColor = Color.Transparent;
Controls.Add(RadioButtonX);
}
private void InitializePanel_Wall(Panel PanelX)
{
PanelX.BackColor = Color.PaleTurquoise;
PanelX.BorderStyle = BorderStyle.Fixed3D;
PanelX.BringToFront();
Controls.Add(PanelX);
}
private void MyProcedure()
{
int i;
for (i = 1; i <= 100; i++)
{
Panel_WallFirstStorey[i] = new Panel();
InitializePanel_Wall(Panel_WallFirstStorey[i]);
Panel_WallFirstStorey[i].Location = new Point(Label_SeparatorLineVertical[ColumnMinimum + i].Location.X, Label_SeparatorLineHorizontal[RowMinimum + i].Location.Y);
Panel_WallFirstStorey[i].Width = (Label_SeparatorLineVertical[ColumnMaximum].Location.X - Label_SeparatorLineVertical[ColumnMinimum].Location.X) / (ColumnMaximum - ColumnMinimum);
Panel_WallFirstStorey[i].Height = CheckBoxWidth;
Panel_WallFirstStorey[i].SendToBack();
}
for (i = 1; i <= 100; i++)
{
RadioButton_WallFirstStorey_Yes[i] = new RadioButton();
RadioButton_WallFirstStorey_No[i] = new RadioButton();
Panel_WallFirstStorey[i].Controls.Add(RadioButton_WallFirstStorey_Yes[i]);//I add this stuff
Panel_WallFirstStorey[i].Controls.Add(RadioButton_WallFirstStorey_No[i]);//I add this stuff
InitializeRadioButton_Wall(RadioButton_WallFirstStorey_Yes[i]);
InitializeRadioButton_Wall(RadioButton_WallFirstStorey_No[i]);
RadioButton_WallFirstStorey_Yes[i].Text = "Yes";
RadioButton_WallFirstStorey_No[i].Text = "No";
RadioButton_WallFirstStorey_Yes[i].Location = new Point(Panel_WallFirstStorey[i].Width / 3, 0);
RadioButton_WallFirstStorey_No[i].Location = new Point(Panel_WallFirstStorey[i].Width * 2 / 3, 0);
RadioButton_WallFirstStorey_Yes[i].Font = SystemFonts.DefaultFont;
RadioButton_WallFirstStorey_No[i].Font = SystemFonts.DefaultFont;
RadioButton_WallFirstStorey_Yes[i].BringToFront();
RadioButton_WallFirstStorey_No[i].BringToFront();
}
}
}

Wow, your code is wrong in so many ways.... It creates controls over and over whenever a panel is painted, but it never really adds them anywere.
To add a radio button b to a panel p, it would be enough to do this:
RadioButton b = new RadioButton();
// Set properties for button here (text, location, handlers, etc.)
p.Controls.Add(b);
I'd try the following procedure instead of yours:
private void MyProcedure()
{
for (i = 1; i <= 100; i++)
{
RadioButton_WallFirstStorey_Yes[i] = new RadioButton();
RadioButton_WallFirstStorey_No[i] = new RadioButton();
InitializeRadioButton_Wall(RadioButton_WallFirstStorey_Yes[i]);
InitializeRadioButton_Wall(RadioButton_WallFirstStorey_No[i]);
RadioButton_WallFirstStorey_Yes[i].Text = "Yes";
RadioButton_WallFirstStorey_No[i].Text = "No";
RadioButton_WallFirstStorey_Yes[i].Location = new Point(Panel_WallFirstStorey[i].Location.X + Panel_WallFirstStorey[i].Width / 3, Panel_WallFirstStorey[i].Location.Y);
RadioButton_WallFirstStorey_No[i].Location = new Point(Panel_WallFirstStorey[i].Location.X + Panel_WallFirstStorey[i].Width * 2 / 3, Panel_WallFirstStorey[i].Location.Y);
Panel_WallFirstStorey[i].Controls.Add(RadioButton_WallFirstStorey_Yes[i]);
Panel_WallFirstStorey[i].Controls.Add(RadioButton_WallFirstStorey_No[i]);
}
}
The following code indicates you're still doing it wrong, adding the radio buttons to the form itself, but positioning them as if you had added them to the panel:
RadioButton_WallFirstStorey_Yes[i].Location = new Point(Panel_WallFirstStorey[i].Location.X + Panel_WallFirstStorey[i].Width / 3, Panel_WallFirstStorey[i].Location.Y);
If you added the button to the panel, it would most probably be invisible because it is outside the panel. If you added the button to the panel, you'd have to use coordinates relative to the panel's client area.
RadioButton_WallFirstStorey_Yes[i].Location = new Point(Panel_WallFirstStorey[i].Width / 3, 0);
RadioButton_WallFirstStorey_No[i].Location = new Point(Panel_WallFirstStorey[i].Width * 2 / 3, 0);
Your update code shows clearly where your error is:
private void InitializeRadioButton_Wall(RadioButton RadioButtonX)
{
RadioButtonX.AutoSize = true;
RadioButtonX.Font = SystemFonts.DefaultFont;
RadioButtonX.BackColor = Color.Transparent;
// REMOVE THIS LINE!!
Controls.Add(RadioButtonX);
}
The last line adds the radio button to the form. As we've been telling you all the time. Remove the line I marked above. Then, the radio buttons will be added to the panels only. After that it is a question of getting the positions right.

You can for example create a panel (or a GroupBox) and in a loop add the RadioButtons.
It should work like with any other control in Winforms.
// Adds 10 Radiobuttons with the name "Radio <number>"
public Form1()
{
InitializeComponent();
for (int n = 0; n < 10; n++)
{
// First instantiate a new RadioButton.
RadioButton button = new RadioButton();
// Now the name of the button.
button.Text = "Radio" + n;
// Dock the button to the top of the GroupBox (to put them in order)
button.Dock = DockStyle.Top;
// Add the button to the GroupBox.
this.groupBoxRadio.Controls.Add(button);
}
}

Your question is not very clear, and no code for context, but you should be able to create an instance of a new radiobutton and add it to the controls of the panel.
It may also be best to use RadioButtonList like Harvey has mentioned, but to try to answer your question:
var someRadioBtn = new RadioButton();
// set properties...
pnlMyPanel.Controls.Add(someRadioBtn);

Adding dynamic controls to winform not working

I am creating dynamic PictureBox and label in WinForms. For this I have created a method which creates these items on the basis of given integer. In the first run while loading the form, its works smoothly, but when I pass any integer from a dropdown box, it does not make any changes. I tried debugging the code, and all the labels are created accordingly but it is not reflected in the winForm. I tried using Invalidate, Update, Refresh but non of them worked.
Here is the method that I have implemented.
private void createPictureBox(int size)
{
//this.Controls.Clear();
panel1.Controls.Clear();
Label[] ParameterLabel = new Label[size];
PictureBox[] ParameterBack = new PictureBox[size];
int y_value = 11;
this.Refresh();
for (int i = 0; i < size; ++i)
{
ParameterLabel[i] = new Label();
ParameterLabel[i].Text = "Test Text";
ParameterLabel[i].Font = new System.Drawing.Font("Calibri", 8, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(128)));
ParameterLabel[i].ForeColor = System.Drawing.Color.White;
ParameterLabel[i].BackColor = System.Drawing.Color.FromArgb(1, 0, 64);
ParameterLabel[i].Size = new System.Drawing.Size(145, 20);
ParameterLabel[i].Location = new Point(30, y_value);
ParameterLabel[i].Anchor = AnchorStyles.Left;
ParameterLabel[i].Visible = true;
ParameterBack[i] = new PictureBox();
ParameterBack[i].Image = Image.FromFile(STR_SETTING_PATH + "\\" + STR_IDEA_NO_XXXXX + "_01_nv.png");
ParameterBack[i].Size = new System.Drawing.Size(400, 32);
ParameterBack[i].Location = new Point(2, y_value - 10);
ParameterBack[i].Anchor = AnchorStyles.Left;
ParameterBack[i].Visible = true;
//this.Controls.Add(ParameterBack[i]);
y_value += 37;
}
panel1.Controls.AddRange(ParameterLabel);
panel1.Controls.AddRange(ParameterBack);
panel1.Invalidate();
}

Who can you distinguish between controls created in the first call and those created in other calls? I've tested your function with a tiny change, it seems to be working fine:
int CallIndex = 0; // this is on the form level
private void button1_Click(object sender, EventArgs e)
{
createPictureBox(3);
CallIndex += 1;
}
private void createPictureBox(int size)
{
// this has the exact same code as your method (copy-paste into my visual studio),
// except this change:
// ParameterLabel[i].Text = "Test Text";
ParameterLabel[i].Text = string.Format("Test {0}", CallIndex); // instead of the row above
}

I did remove the previously added controls and added the new one after which apparently solved my problem. The problem was due to piling of Controls one over another. I first removed the previously created controls using
this.Controls.Remove(UserControl1);
Then re-created its instance, which solved my problem.

Visual Studio-style undo drop-down button - custom ToolStripSplitButton

I'm looking to implement a Visual Studio-style undo drop-down button:
I've looked all over the internet, and can't seem to find any real implementations of this.
I've started by deriving from ToolStripSplitButton, but don't really know where to go from there. Its DropDown property is a ToolStripDropDown, but that doesn't seem to have anything regarding multiple items being selected, much less scrolling, and the text at the bottom.
So instead of the default ToolStripDropDown, I'm thinking maybe the whole drop down part should be a custom control, based on a combobox. The question then, is how to cause the right-side (drop down arrow) button to do something other than show its default drop down?
Am I on the right track here? Thanks!

Yes, I think you're on the right track. And in this case, ToolStripControlHost is your friend.
You don't necessarily need to derive from it (unless you are making your own control), but try just subscribing to the ToolStripSplitButton's DropDownOpening event:
Working example:
private ListBox listBox1;
public Form1()
{
InitializeComponent();
listBox1 = new ListBox();
listBox1.IntegralHeight = false;
listBox1.MinimumSize = new Size(120, 120); \\ <- important
listBox1.Items.Add("Item 1");
listBox1.Items.Add("Item 2");
}
private void toolStripSplitButton1_DropDownOpening(object sender, EventArgs e) {
ToolStripControlHost toolHost = new ToolStripControlHost(listBox1);
toolHost.Size = new Size(120, 120);
toolHost.Margin = new Padding(0);
ToolStripDropDown toolDrop = new ToolStripDropDown();
toolDrop.Padding = new Padding(0);
toolDrop.Items.Add(toolHost);
toolDrop.Show(this, new Point(toolStripSplitButton1.Bounds.Left,
toolStripSplitButton1.Bounds.Bottom));
}
Here is the result:
For your application, you would need to replace the ListBox with your own UserControl, so you can contain whatever your want in it. The ToolStripControlHost can only hold one control, and it's important to set the MinimumSize property, or else the dropped control isn't sized correctly.

Extra thanks to LarsTech! (I didn't know about ToolStripControlHost a few hours ago)
Here is my implementation, which is really close to the VS drop down...
You should be able to just drop this delegate & function into your Form:
public delegate void UndoRedoCallback(int count);
private void DrawDropDown(ToolStripSplitButton button, string action, IEnumerable<string> commands, UndoRedoCallback callback)
{
int width = 277;
int listHeight = 181;
int textHeight = 29;
Panel panel = new Panel()
{
Size = new Size(width, textHeight + listHeight),
Padding = new Padding(0),
Margin = new Padding(0),
BorderStyle = BorderStyle.FixedSingle,
};
Label label = new Label()
{
Size = new Size(width, textHeight),
Location = new Point(1, listHeight - 2),
TextAlign = ContentAlignment.MiddleCenter,
Text = String.Format("{0} 1 Action", action),
Padding = new Padding(0),
Margin = new Padding(0),
};
ListBox list = new ListBox()
{
Size = new Size(width, listHeight),
Location = new Point(1,1),
SelectionMode = SelectionMode.MultiSimple,
ScrollAlwaysVisible = true,
Padding = new Padding(0),
Margin = new Padding(0),
BorderStyle = BorderStyle.None,
Font = new Font(panel.Font.FontFamily, 9),
};
foreach (var item in commands) { list.Items.Add(item); }
if (list.Items.Count == 0) return;
list.SelectedIndex = 0;
ToolStripControlHost toolHost = new ToolStripControlHost(panel)
{
Size = panel.Size,
Margin = new Padding(0),
};
ToolStripDropDown toolDrop = new ToolStripDropDown()
{
Padding = new Padding(0),
};
toolDrop.Items.Add(toolHost);
panel.Controls.Add(list);
panel.Controls.Add(label);
toolDrop.Show(this, new Point(button.Bounds.Left + button.Owner.Left, button.Bounds.Bottom + button.Owner.Top));
// *Note: These will be "up values" that will exist beyond the scope of this function
int index = 1;
int lastIndex = 1;
list.Click += (sender, e) => { toolDrop.Close(); callback(index); };
list.MouseMove += (sender, e) =>
{
index = Math.Max(1, list.IndexFromPoint(e.Location) + 1);
if (lastIndex != index)
{
int topIndex = Math.Max(0, Math.Min(list.TopIndex + e.Delta, list.Items.Count - 1));
list.BeginUpdate();
list.ClearSelected();
for (int i = 0; i < index; ++i) { list.SelectedIndex = i; }
label.Text = String.Format("{0} {1} Action{2}", action, index, index == 1 ? "" : "s");
lastIndex = index;
list.EndUpdate();
list.TopIndex = topIndex;
}
};
list.Focus();
}
You can set it up and test like this, assuming you have a blank form (Form1) with a toolStrip that has 1 ToolStripSplitButton (toolStripSplitButton1) added:
public Form1()
{
InitializeComponent();
// Call DrawDropDown with:
// The clicked ToolStripSplitButton
// "Undo" as the action
// TestDropDown for the enumerable string source for the list box
// UndoCommands for the click callback
toolStripSplitButton1.DropDownOpening += (sender, e) => { DrawDropDown(
toolStripSplitButton1,
"Undo",
TestDropDown,
UndoCommands
); };
}
private IEnumerable<string> TestDropDown
{
// Provides a list of strings for testing the drop down
get { for (int i = 1; i < 1000; ++i) { yield return "test " + i; } }
}
private void UndoCommands(int count)
{
// Do something with the count when an action is clicked
Console.WriteLine("Undo: {0}", count);
}
Here is a better example using the Undo/Redo system from: http://www.codeproject.com/KB/cs/AutomatingUndoRedo.aspx
public Form1()
{
InitializeComponent();
// Call DrawDropDown with:
// The Undo ToolStripSplitButton button on the Standard tool strip
// "Undo" as the action name
// The list of UndoCommands from the UndoRedoManager
// The Undo method of the UndoRedoManager
m_TSSB_Standard_Undo.DropDownOpening += (sender, e) => { DrawDropDown(
m_TSSB_Standard_Undo,
"Undo",
UndoRedoManager.UndoCommands,
UndoRedoManager.Undo
); };
}
*Note: I did modify the Undo & Redo methods in the UndoRedoManager to accept a count:
// Based on code by Siarhei Arkhipenka (Sergey Arhipenko) (http://www.codeproject.com/KB/cs/AutomatingUndoRedo.aspx)
public static void Undo(int count)
{
AssertNoCommand();
if (CanUndo == false) return;
for (int i = 0; (i < count) && CanUndo; ++i)
{
Command command = history[currentPosition--];
foreach (IUndoRedo member in command.Keys)
{
member.OnUndo(command[member]);
}
}
OnCommandDone(CommandDoneType.Undo);
}

I'd suggest implementing the popup separately from the toolbar button. Popups are separate windows with a topmost-flag which auto-close when losing focus or pressing escape. If you code your own popup window that frees you from having to fit your behaviour to a preexisting model (which is going to be hard in your case). Just make a new topmost window with a listbox and status bar, then you are free to implement the selection behavior on the listbox like you need it.

Vs 2010 is a WPF application. If you are in the beginning of this application development than use WPF as a core technology. WPF drop down button is implemented in WPF ribbon. Source code is available on CodePlex.

Dynamic creation of control

for (int i = 0; i < 200; i++)
{
Control control = new Control();
control = new CheckBox();
Size size = control.Size;
Point point = new Point(20, 22);
control.Location = point;
int width = size.Width + 5;
i += width;
list.Add(control);
}
foreach(Control c in list)
{
}
how do I create a new instance of checkbox? Because this way I am getting just one checkbox each time. I want to get three checkbox in each row.

Is this winforms? A first point: you don't need the new Control() each time (you simly discard it anyway when you new CheckBox(). How exactly do you want the layout to appear? Can you describe it a bit more please?
I imagine TableLayoutPanel might be a reasonable start...
[STAThread]
static void Main() {
Application.EnableVisualStyles();
Form form = new Form();
TableLayoutPanel layout = new TableLayoutPanel();
layout.Dock = DockStyle.Fill;
form.Controls.Add(layout);
layout.AutoScroll = true;
layout.ColumnCount = 3;
// size the columns (choice just to show options, not to be pretty)
layout.ColumnStyles.Add(new ColumnStyle(SizeType.Absolute, 200));
layout.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 50));
layout.ColumnStyles.Add(new ColumnStyle(SizeType.AutoSize));
layout.GrowStyle = TableLayoutPanelGrowStyle.AddRows;
for (int i = 0; i < 200; i++)
{
CheckBox chk = new CheckBox();
chk.Text = "item " + i;
layout.Controls.Add(chk);
}
Application.Run(form);
}
Otherwise, you'll need to manually set the Location (or Top and Left) of each; not simple.

Your code has problems. Let's work from sample code rather than a lesson. I'll create a Panel first, nice if you want to remove the checkboxes you created. You'd probably be interested in the user clicking a checkbox so lets add an event for that. Start a new WF project and drop a button on the form. Double click it, then paste this code:
private void button1_Click(object sender, EventArgs e) {
// Give the 3 checkboxes a decent spacing
int height = this.Font.Height * 3 / 2;
// Create the panel first, add it to the form
Panel pnl = new Panel();
pnl.Size = new Size(100, 3 * height);
pnl.Location = new Point(10, 5);
this.Controls.Add(pnl);
// Make three checkboxes now
for (int ix = 0; ix < 3; ++ix) {
CheckBox box = new CheckBox();
box.Size = new Size(100, height);
// As pointed out, avoid overlapping them
box.Location = new Point(0, ix * height);
box.Text = "Option #" + (ix + 1).ToString();
box.Tag = ix;
// We want to know when the user checked it
box.CheckedChanged += new EventHandler(box_CheckedChanged);
// The panel is the container
pnl.Controls.Add(box);
}
}
void box_CheckedChanged(object sender, EventArgs e) {
// "sender" tells you which checkbox was checked
CheckBox box = sender as CheckBox;
// I used the Tag property to store contextual info, just the index here
int index = (int)box.Tag;
// Do something more interesting here...
if (box.Checked) {
MessageBox.Show(string.Format("You checked option #{0}", index + 1));
}
}

It looks like you get your 200 instances, all placed at the same point.

Instantiate 3 new checkboxes inside your loop body, set their properties accordingly and add each of them to the list. After the code above is complete, you will have 600 checkboxes.
list.Add(Control1);
list.Add(Control2);
list.Add(Control3);

I am not sure about what you are trying to do, but I cleaned up your code a bit:
for (int i = 0; i < 200; i++)
{
Control control = new CheckBox();
control.Location = new Point(20, 22);
i += control.Size.Width + 5;
list.Add(control);
}
You should not add a new instance to the list if you want to add the control you just made.
Also:
Control control = new Control();
control = new CheckBox();
Is a bit redundant. Also to not get one control at the same spot multiple times you should alter the point. Hope this helps