Removing dynamically generated buttons - c#

I'm working with C# windows forms and need some help. I have a button that creates other buttons and adds them to the list 'buttons'. I need to have each button created destroy itself when it is clicked.
//create new button
Button newButton = new Button();
newButton.Name = "aButt"+buttNum;
Debug.WriteLine(newButton.Name);
buttNum++;
newButton.Text = "Button!";
newButton.Height = 50;
newButton.Width = 50;
//controls where the new button gets placed
if (curX > 9)
{
curX = 0;
curY++;
//defines the point the button spawns
newButton.Location = new System.Drawing.Point((curX * 55)+10, curY * 55);
//increments X to avoid placing a button on top of another
curX++;
}
else
{
newButton.Location = new System.Drawing.Point((curX * 55) + 10, curY * 55);
curX++;
}
newButton.UseVisualStyleBackColor = true;
newButton.Click += new System.EventHandler(this.removeThisButton);
buttons.Add(newButton);
this.Controls.Add(newButton);
I have the event listener set up, but since the sender has no actual information on the button itself i'm not sure how to get rid of it.
Any help is appreciated!

The click event handler has the signature
private void myButton_Click(object sender, EventArgs e)
The object sender is the source of the event. Just cast that to a Button, and there's what got clicked:
Button whatWasClicked = sender as Button;
if(whatWasClicked == null)
// never mind -- it wasn't a button...

Sender is the button. You can remove it from Form's control collection like this:
private void removeThisButton(object sender, EventArgs e) {
this.Controls.Remove(sender);
}

Related

How to know what Linklabel has been clicked?

Background
I have created 8 linklabels which are created using a loop which gets data from a database.
Each record fills a linklabel.
How ever how can I distinguish what linklabel has been clicked on?
Code
for (int i = 0; i <= rowCount - 1; i++)
{
LinkLabel Linklabel = new LinkLabel();
Linklabel.Text = ds.Tables[0].Rows[i]["code"].ToString();
Linklabel.Height = 15;
Linklabel.Width = 50;
Linklabel.AutoSize = true;
Linklabel.Location = new Point(10, (i + 1) * 30);
tabControl1.TabPages[0].Controls.Add(Linklabel);
// Add an event handler to do something when the links are clicked.
Linklabel.LinkClicked += new System.Windows.Forms.LinkLabelLinkClickedEventHandler(this.linkLabel1_LinkClicked);
}
private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
tabControl1.SelectedTab = tabPage2;
}
When clicking on any of the 8 linklabels that are drawn the same thing will happen.
What I would like to happen?
When clicking on any of the linklabels I would like to change a label.text to what the contents of the clicked linklabel was.
For example
If the first linklabel.text=("one") is clicked on label1.text becomes one.
If the second linkedlabel.text=("two") is clicked on label1.text becomes two.
You could use the sender argument in the callback which will point to the actual LinkLabel being clicked:
private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
label1.text = ((LinkLabel)sender).Text;
}

Capture the right button click event

I'm playing around abit with winforms and its controls and just discovered how to do custommade buttonclicks. However, there is a problem. I've got a loop, that's looping through a list of elements, and if a condition appears - I'm creating a button that will pop up a gridview.
public void draw(ref Panel inputPanel) //draws the eventline
{
int stepCounter = 0;
for (int i = 0; i < DaysList.Count-1; i++)
{
Button b1;
if (DaysList[i].Elements.Count > max)
{
b1 = new Button(); //Create the box
b1.Width = 120;
b1.Height = 40; //Set width and height
b1.Location = new Point(stepCounter + 35, 70); //Location
inputPanel.Controls.Add(b1); //
b1.Text = "Check event date in grid";
b1.Show();
b1.BringToFront();
b1.Click += new EventHandler((sender, e) => btn_Click(sender, e, DaysList[i].Elements));
stepCounter += 200;
}
}
}
That was my method for creating the buttons and a click event for the when my condition appears. The function that is passed to the eventhandler looks like this:
public void btn_Click(object sender, EventArgs e, List<EventElement> inputElems)
{
Button button = sender as Button;
DataGridForm window = new DataGridForm(inputElems);
window.Show();
}
public class EventElement
{
public EventElement()
{
}
public int Count{get;set;}
public string Date{get;set;}
}
The clickpart of the event is fine but whenever i click the spawned buttons, I get the wrong data into the gridview. As an example: The loop has created four buttons for me and they are presented on a straight line on the form. But whenever i click one of the buttons - dosnt matter which one of them, the button always return the data of the last spawned button. A more clear example: lets say we have the list inputElems looks like this:
inputElems[0].Count -> 2644
inputElems[1].Count -> 2131
inputElems[2].Count -> 8467
inputElems[3].Count -> 5462
When i now click the second button, the input to the second buttons parameter list should have the values (sender, e, 2131), right? but for some reason, the last argument gets the same like the 4th element in the list, even though i call the secondly created button.
I figured that it has something to do with me always calling the last added button_click to the eventhandler of the button, if so, how do I call different clicks from the EventHandler?
Instead of passing inputElems with the EventHandler, you can use Tag.
E.g. use:
b1.Tag=i;
Then in your click event handler:
public void btn_Click(object sender, EventArgs e)
{
Button button = sender as Button;
DataGridForm window = new DataGridForm(DaysList[int.Parse(button.Tag.ToString())].Elements);
window.Show();
}
The problem is that the for loop is out of scope, and thus unable to provide you with the data you're looking for. A more straight forward approach might be something like this:
public void draw(ref Panel inputPanel) //draws the eventline
{
int stepCounter = 0;
for (int i = 0; i < DaysList.Count-1; i++)
{
Button b1;
if (DaysList[i].Elements.Count > max)
{
b1 = new Button(); //Create the box
b1.Width = 120;
b1.Height = 40; //Set width and height
b1.Location = new Point(stepCounter + 35, 70); //Location
inputPanel.Controls.Add(b1); //
b1.Text = "Check event date in grid";
b1.Show();
b1.BringToFront();
b1.Tag = DaysList[i].Elements;
b1.Click += btn_Click;
stepCounter += 200;
}
}
}
and then in btn_Click, do this:
public void btn_Click(object sender, EventArgs e)
{
Button button = sender as Button;
int inputElems = (List<EventElement>)button.Tag;
DataGridForm window = new DataGridForm(inputElems);
window.Show();
}

How to delete a button when another button is clicked?

It's probably quite trivial, but my problem is I need to delete two buttons when one of them is clicked. At the moment, my code will create these two buttons when a third is clicked. What I want is for one of these options to do something (this I have done) and, once complete, make these buttons disappear again. Here is the code to create two buttons:
private void btnRandom_Click(object sender, EventArgs e)
{
Button d = new Button();
Button c = new Button();
d.Text = "Dice";
c.Text = "Chance Card";
d.Name = "btnDice";
c.Name = "btnCC";
d.Location = new Point(btnRandom.Location.X, btnRandom.Location.Y + 30);
c.Location = new Point(btnRandom.Location.X, btnRandom.Location.Y + 60);
d.Click += new EventHandler(d_Click);
c.Click += new EventHandler(c_Click);
this.Controls.Add(d);
this.Controls.Add(c);
}
And below is my failed attempt at removing this button
private void d_Click(object sender, EventArgs e)
{
this.Controls.Remove(btnDice); // This doesnt work
}
I guess you code is OK, but you need to re-paint the form after removing the control.
this.Controls.Remove(btnDice);
this.Refresh();
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.refresh.aspx
You can disable the button using
this.btnDice.Enabled = false;
or you can use visible property to hide it
e.g.
this.btnDice.Visible = false;
For removing You might need to refresh the form.
Why don't you just make the button disappear and reappear again ?
//Make the button disappear
this.btnDice.Visible = false;
//Make the button reappear
this.btnDice.Visible = true;
you can try this by removing the sender :
private void d_Click(object sender, EventArgs e)
{
this.Controls.Remove((Button)(sender));
this.Refresh();
}

Address a generated button for clickevent

I have a class that creates panels with controls based on my database. It creates a panel with a button on each panel, per row in DB. How do I address one specific button to make a click event?
I'm a rookie, and maybe abit over my head, but you don't learn to swim in shallow water ;)
Any help appreciated!
while (myDataReader.Read())
{
i++;
Oppdrag p1 = new Oppdrag();
p1.Location = new Point (0, (i++) * 65);
oppdragPanel.Controls.Add(p1);
p1.makePanel();
}
class Oppdrag : Panel
{
Button infoBtn = new Button();
public void makePanel()
{
this.BackColor = Color.White;
this.Height = 60;
this.Dock = DockStyle.Top;
this.Location = new Point(0, (iTeller) * 45);
infoBtn.Location = new Point(860, 27);
infoBtn.Name = "infoBtn";
infoBtn.Size = new Size(139, 23);
infoBtn.TabIndex = 18;
infoBtn.Text = "Edit";
infoBtn.UseVisualStyleBackColor = true;
}
}
You'll need a method that matches the event thrown by clicking on the button.
i.e.)
void Button_Click(object sender, EventArgs e)
{
// Do whatever on the event
}
Then you'll need to assign the click event to the method.
p1.infoBtn.Click += new System.EventHandler(Button_Click);
Hope this helps.
You can add the event handler for the button when you create the button. You can even add a unique CommandArgument per button so you can distinguish one button from another.
public void makePanel()
{
/* ... */
infoBtn.UseVisualStyleBackColor = true;
infoBtn.Click += new EventHandler(ButtonClick);
infoBtn.CommandArgument = "xxxxxxx"; // optional
}
public void ButtonClick(object sender, EventArgs e)
{
Button button = (Button)sender;
string argument = button.CommandArgument; // optional
}

How to move a new (custom) button at run time?

I have a problem with my winforms C# project.
I want to move a new (custom) button around the form (at run time).
How can I do that?
Button[] buttons = new Button[1000];
int counter = 0;
Button myText = new Button();
private void button2_Click(object sender, EventArgs e)
{
Button myText = new Button();
myText.Tag = counter;
myText.Location = new Point(x2,y2);
myText.Text = Convert.ToString(textBox3.Text);
this.Controls.Add(myText);
myText.MouseMove += new MouseEventHandler(myText_MouseMove);
myText.MouseDown += new MouseEventHandler(myText_MouseDown);
buttons[counter] = myText;
counter++;
}
public void myText_MouseMove(object sender, MouseEventArgs e)
{
int s = e.GetHashCode();
int check = 0;
for (int i = 0; i < counter; i++)
{
if (buttons[i].GetHashCode() == s)
check = i;
}
if (e.Button == MouseButtons.Left)
{
buttons[check].Left += e.X - move.X;
buttons[check].Top += e.Y - move.Y;
}
}
void myText_MouseDown(object sender, MouseEventArgs e)
{
move = e.Location;
}
I use the code above to create the new button and I am trying to move it around the form.
If I code for just 1 button I am able to move it but, I want to be able to do this for more buttons as well.
Try this
public void myText_MouseMove(object sender, MouseEventArgs e)
{
Button button = (Button)sender;
if (e.Button == MouseButtons.Left)
{
button .Left += e.X - move.X;
button .Top += e.Y - move.Y;
}
}
I've come across this thread while doing something similar.
Even though the thread is quite old; I'm sharing the way I've achieved this.
Notes:
Unlike the operator question above; in the example bellow; I'm not using a Button[] (array) with 1000 buttons; (but this can be easily changed).
In the example bellow I have:
A Form with 1 Button on it.
When this button is clicked; it will create a new (Custom) Button
(hence; having two button click events in the code simply for the test purpose).
Bellow you can find: A way to generate the button; and so how to drag it around the form.
/* Variables */
// Used to Store the Mouse Location on the Screen when Button is Clicked
private Point mouseDownLocation;
// Used to know if the Button can be Moved.
private bool isMoveable = false;
// Used to prevent clicking the button when being dragged
private bool clickEnabled = true;
/// <summary> Occurrs when the visible button on the Form is clicked. </summary>
private void Button_Click(object sender, EventArgs e)
{
// Create a variable to set the Size of the new Button.
Size size = new Size(100, 100);
// Create the Button. Specifying the Button Text and its Size.
CreateButton("Button Text", size);
}
/* Custom Button : Create & Configure the Button */
private void CreateButton(string btnText, Size btnSize)
{
// Create the Button instance:
Button btn = new Button();
// Custom Button Style Configuration Code.
// i.e: FlatStyle; FlatAppearance; BackColor; ForeColor; Text; Size; Location; etc...
btn.FlatStyle = FlatStyle.Standard;
btn.FlatAppearance.BorderColor = Color.White;
btn.BackColor = Color.Purple;
btn.ForeColor = Color.White;
btn.Text = btnText;
btn.Size = btnSize;
btn.Location = new Point(100, 100);
// Custom Button Event.
btn.Click += new EventHandler(CustomButton_Click);
btn.MouseDown += new MouseEventHandler(CustomButton_MouseDown);
btn.MouseMove += new MouseEventHandler(CustomButton_MouseMove);
btn.MouseUp += new MouseEventHandler(CustomButton_MouseUp);
// Add Button to Control Collection.
Controls.Add(btn);
// Show Button.
btn.Show();
}
/* Custom Button Events */
/// <summary> Occurrs whenever the Custom Button is Clicked </summary>
private void CustomButton_Click(object sender, EventArgs e)
{
if (clickEnabled)
{
// Note: The "for" loop bellow lets you get the current button; so you can drag it.
Button btn = (Button)sender;
// Iterate over the Form Controls
for (int i = 0; i < Controls.Count; i++)
{
// If the Button Clicked Corresponds to a Found Index in Control Collection...
if (i == Controls.IndexOf(btn))
{
// Perform Corresponding Button Action.
MessageBox.Show(btn.Name + " Clicked!");
}
}
}
}
/// <summary> Occurrs whenever Left Mouse Button Clicks the Button and is Kept Down. </summary>
private void CustomButton_MouseDown(object sender, MouseEventArgs e)
{
// Check if Left Mouse Button is Clicked.
if (e.Button == MouseButtons.Left)
{
// Set mouseDownLocation (Point) variable, according to the current mouse location (X and Y).
mouseDownLocation = e.Location;
// Enable the hability to move the Button.
isMoveable = true;
}
}
/// <summary> Occurrs whenever Left Mouse Button is Down and Mouse is Moving the Button. </summary>
private void CustomButton_MouseMove(object sender, MouseEventArgs e)
{
Button btn = (Button)sender;
// If the hability to move the button is "true" and the mouse button used to drag the button is the left mouse button:
if (isMoveable)
{
if (e.Button == MouseButtons.Left)
{
// Set the Button location X and Y...
btn.Left = e.X + btn.Left - mouseDownLocation.X;
btn.Top = e.Y + btn.Top - mouseDownLocation.Y;
}
}
// Disable Click hability (See: Note at the end of this post).
clickEnabled = false;
}
/// <summary> Occurrs whenever Left Mouse Button is not longer being hold down (Left Mouse Button is Up). </summary>
private void CustomButton_MouseUp(object sender, MouseEventArgs e)
{
// Disables the hability to move the button
isMoveable = false;
clickEnabled = true;
}
Note: The Custom Button Click interferes with the MouseDown Event. In a "simple" manner:
I updated the code by including a boolean value to prevent clicking the button when actually it is being dragged.
Hope this helps you out understanding how to accomplish this feature.
Hope this helps people out achieving this goal.

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