Develop Reference

Is there a better way to close buttons on click?

I'm a beginner and have an assignment in which I must program the game of NIM. I begin with 15 "tokens" and at each turn a maximum of three can be removed, or "hidden". So far I am hiding these tokens on click by doing the following.
private void button1_Click(object sender, EventArgs e)
{
button1.Visible = false;
}
private void button2_Click(object sender, EventArgs e)
{
button2.Visible = false;
}
I simply copied and pasted that multiple times and changed the button numbers so that my buttons will close on click. This might be obvious, but is there a more efficient way to do this, instead of having 15 button close methods?

You can use the same click event for every single button, and make use of the sender object, casting it to Button:
private void buttonsToClose_Click(object sender, EventArgs e)
{
((Button)sender).Visible = false;
}
Then just add that handler to every single button you want to close itself on click.
Note, though, that this will throw an InvalidCastException if you or anyone else uses this handler on an object that is not a Button, so if you're actually going to use this code I would add some sort of conditional to check the real type of the sender.
Additionally, you could reuse this for any Control object by casting sender to Control instead, given that Button inherits from Control, and all Control objects have the Visible property. Here's an example, with a conditional to guard against an invalid cast:
private void controlToMakeInvisible_Click(object sender, EventArgs e)
{
if (sender.GetType() == typeof(Control))
{
((Control)sender).Visible = false;
}
}
A final note - it seems from your post like you may have a slight misunderstanding about the way events are created and wired in with objects in Windows Forms. If you go into the Designer, add a click event, and see it pop into your Form code as follows:
private void button1_Click(object sender, EventArgs e)
the name of this method has no bearing on its function. The button1 part of button1_Click doesn't actually have any logical linkage with the Button button1 - it's just the default name assigned by the Designer. The actual assignment of the method button1_Click to the Button.Click event is auto-generated into your Form's Designer.cs method.
The point of this is that if you copy and paste button1_Click and change every incidence of button1 with button2, like so:
private void button2_Click(object sender, EventArgs e)
{
button2.Visible = false;
}
it's not going to fire when button2 gets clicked. In actual fact, it's never going to fire at all, because the method hasn't actually been connected to any controls/events.

just call your event in a foreach loop.
private void Form1_Load(object sender, EventArgs e)
{
foreach (var button in Controls.OfType<Button>())
{
button.Click += button_Click;
}
}
void button_Click(object sender, EventArgs e)
{
((Control) sender).Visible = false;
}
if you change:
Controls.OfType<Button>()
to
Controls.OfType<Control>()
it will set visible to false for any Control. so you can control what item you want the event to be raised for easily.
OfType summary: Filters the elements of an IEnumerable based on a specified type.

Can't seem to add button to another tabpage

I have a TabControl with three TabPages. On tabPage2 there is one button. I want to click on tabPage3 and see this button. I've searched around and the code below is susposed to work but when I click on tabPage3 from tabPage2, I don't see the button.
I must be missing something else?
Thanks for any help...
private void tabPage3_Click(object sender, EventArgs e)
{
this.tabPage3.Controls.Add(this.button1);
}

This sort of thing is going to cause you problems. Add a second button, or, if a single button must be visible, place it outside the TabControl altogether. Making controls hop around like that is a bad idea.

You could use the SelectedIndexChanged() event:
private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
{
tabControl1.SelectedTab.Controls.Add(this.button1);
}
If you only wanted it to move between tabs 2 and 3 specifically:
private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
{
if (tabControl1.SelectedIndex == 1 || tabControl1.SelectedIndex == 2)
{
tabControl1.SelectedTab.Controls.Add(this.button1);
}
}
As DonBoitnott pointed out, though, it can cause problems depending on how the form is laid out.

C# Tabless Control Previous/Back/Return Button failing?

I am hoping someone here can help me, i have a Tabless Control on my windows forms application and basically because the tabs are purposely hidden i have added 2 buttons to each tab "Next" and "Back".
This is the code snippet i have for my "Next" button:
private void nextbutton1_Click(object sender, EventArgs e)
{
tabControl1.SelectedTab = tabPage3;
this.toolStripStatusLabel8.Text = System.DateTime.Now.ToString();
}
Which works fine, however when i use the exact same theory on the "Back" button it does not work:
private void backbutton1_Click(object sender, EventArgs e)
{
tabControl1.SelectedTab = tabmain;
this.toolStripStatusLabel1.Text = System.DateTime.Now.ToString();
}
So my question is how does one go to a previous tabpage from a button? I have looked through here and tried all of the links that came up but nothing has worked any ideas?

You should use the SelectedIndex property instead of using concrete TabPage instances. This way it will still work when you decide to change the order of the pab pages or add new pages:
private void previousButton_Click(object sender, EventArgs e)
{
if (tabControl1.SelectedIndex > 0)
{
tabControl1.SelectedIndex--;
}
}
private void nextButton_Click(object sender, EventArgs e)
{
if (tabControl1.SelectedIndex < tabControl1.TabCount - 1)
{
tabControl1.SelectedIndex++;
}
}
Since there is no "Tabless" tab control in .NET Framework I can only assume that it works similar to the standard TabControl. If the solution doesn't work you should give us some information about the actual class you use.
BTW: There is no need to repeat the buttons on each page. Why don't you just put the buttons outside the TabControl?
Also: I see that you use a ToolStripStatusLabel to show the current time. Instead of updating it each time the user clicks somewhere add a Timer to your form. Set its Interval to 1000 and handle its Tick event. Update the label there:
private void timer1_Tick(object sender, EventArgs e)
{
toolStripStatusLabel1.Text = DateTime.Now.ToLongTimeString();
}
This way it updates constantly and again there is no need to repeat anything. You need to call timer1.Start() in the form's constructor.

Designing a dynamic panel

I am new to C# and I want to design a GUI for a image processing application in c#. I have a very basic rudimentary layout designed as shown below
Here, the image plane is fixed and it will show a live stream video. I have designed all the buttons frame and the side panel. But I do not know how to dynamically change the side panel for each button I click. For example, If I click button1_1, I want some things in the side panel and for button1_2, some other things in it. How do I go about doing it.
EDIT:
Thanks for the answers. I see tab controls is an option. But I want a new panel evertime a click a button. which can further open forms. Is it possible?

OK, let's see. It's easy to do with "TabControl" or array of "Panel"s.
1.Do it with TabControl.
You can design GUI in TabControl in multiple subTabs(if you don't know how please ask.). Then you change it in button click event, to make subTab you wanna show(which means make it visiable and not visiable for other subTabs.)
2.Do it with array of panel.
You can use panel[] panels. In button click event, you hide other panels and show the one you want.
Hope answer helps you!
private void button1_Click(object sender, EventArgs e)
{
tabControl1.SelectedIndex = 0;
tabControl1.TabPages[0].Text = "First";
}
private void button2_Click(object sender, EventArgs e)
{
tabControl1.SelectedIndex = 1;
}
private void button3_Click(object sender, EventArgs e)
{
tabControl1.SelectedIndex = 2;
}

you may want to add split container in your form.
Create UserControl for each buttons.
Code for the button click event
//Button1Click Event
private void button1_Click(object sender, EventArgs e)
{
UserControl1 m_UserControl = new UserControl1();
splitContainer1.Panel2.Controls.Clear();
splitContainer1.Panel2.Controls.Add(m_UserControl);
}
//Button2Click Event
private void button2_Click(object sender, EventArgs e)
{
UserControl2 m_Usercontrol2 = new UserControl2();
splitContainer1.Panel2.Controls.Clear();
splitContainer1.Panel2.Controls.Add(m_Usercontrol2);
}
you can do this if you want to change what usercontrol display in a panel at run time.
Correct me if i misunderstood your question.

In WinForms, you could use a tab control and just change the selected tabs index when a button is pressed. More specifically, when its click event is fired. Here is a good tutorial on using the TabControl and here is a tutorial on wiring up click events.
EDIT:
This is a better tutorial.
Since you can't hide the tabs of a tabcontrol without using WPF, you may need to use something else, if you don't like the way they look. A good workaround if you only have a couple of buttons and thus views, would be to use panels. When button one is clicked show panel one and hide panel two, etc. Here would be the code:
private void button1_Click(object sender, EventArgs e)
{
pane2.visible = false;
pane1.visible = true;
}
private void button2_Click(object sender, EventArgs e)
{
pane1.visible = false;
pane2.visible = true;
}
Hope this helps you!

C# Passing controls around and maintaining events

Say I have a Form which we'll call it ParentForm, and it contains a Panel which we'll call ContainerPanel. Now, ContainerPanel contains a Panel, which we'll call EntityPanel.
So basically, the Form contains A Panel which contains a Panel.
In ContainerPanel, we have:
void EntityPanel_MouseDown(object sender, MouseEventArgs e)
{
ContainerPanel.Controls.Remove(EntityPanel);
ParentForm.AcceptEntityPanel(EntityPanel);
}
and in MainForm, we have:
void AcceptEntityPanel(Panel panel)
{
Controls.Add(panel);
panel.MouseUp += new MouseEventHandler(
delegate(object sender, MouseEventArgs e)
{
MessageBox.Show("Mouse has been released.");
});
}
Note: This is example code only, which I have just typed in here without verifying syntax, etc. I realise it is trivial to combine these two functions into one, however in my application these two functions do several other things and should be separate.
So the EntityPanel, which belongs to ContainerPanel needs to be transferred to ParentForm when the user presses the mouse down.
When the user releases the mouse, I still need the MouseUp event to be triggered, but it is not working.
Previously, I was passing information about the panel and creating a new panel on the parent form, and manually calling the MouseDown method.
What I'm doing now, as you can see in my above example, is that I'm passing the exact same panel back to the parent form. I had hoped that this way the MouseDown/MouseUp would work, however it didn't.
I'm running out of ideas on how else to structure this module of my program.
Any ideas?

This works for me:
void Form1_Load(object sender, EventArgs e)
{
var innerPanel = new Panel();
outerPanel.Controls.Add(innerPanel);
innerPanel.MouseDown += (a,b) =>
{
outerPanel.Controls.Remove(innerPanel);
Controls.Add(innerPanel);
innerPanel.MouseUp += (x,y) => MessageBox.Show("!");
};
}