I've just made two forms and I have two checkboxes, I want they to copy eachother (if the checkBox in Form1 is checked, the checkBox in Form2 is checked)
I dont have a code for this but I can give you my Form1 name And Form2 name
Form1: MainUI
Form2: Settings
You need to fire an event from one form and handle it on the other form.
You'll need an event args class to carry the state of the checkbox:
public class CheckEventArgs : EventArgs
{
public bool Checked { get; set; }
}
Then on your form that will be sending it's check state you'll need an event (let's assume that the Settings form will send it's checkbox state to the MainUI form) so Settings will need this adding:
public event EventHandler<CheckEventArgs> CheckboxChanged;
And on the CheckedChanged event of the checkBox you will fire the event:
public void checkBox1_CheckedChanged(object sender, EventArgs e)
{
CheckboxChanged?.Invoke(this, new CheckEventArgs() { Checked = checkBox1.Checked });
}
On the form you want to receive the result from you'll need to handle that event (this code goes on MainUI):
public Form1()
{
InitializeComponent();
Form2 Settings = new Form2();
Settings.CheckboxChanged += settings_CheckboxChanged;
}
public void settings_CheckboxChanged(object sender, CheckEventArgs e)
{
checkBox1.Checked = e.Checked;
}
I would suggest that you don't use this to send in both directions without some modifications. Otherwise you will end up in an infinite loop firing the event back and forth between the two forms. Just use it in one direction and you'll be fine.
Related
I have 2 forms - Mainmenu form , that clicks to a registration from.
On the registration form, I have a button. I want the form to automatically click when the form is loaded. Below is what I have tried so far but it doesn't work. Any suggestions?
public Membershipform()
{
InitializeComponent();
Button_1.PerformClick();
}
The problem is that you're calling PerformClick() in the Form's constructor. At which point, the Visible property of the Button is false, causing PerformClick() to fail because in order for it to work, both the Visible and Enabled properties of the button must be true. You can confirm this by checking the source.
Your options:
Move the call to PerformClick() to the Load event of the form.
private void Membershipform_Load(object sender, EventArgs e)
{
Button_1.PerformClick();
}
Move the code in the button's Click event handler to a separate method and call that method from the constructor.
public Membershipform()
{
InitializeComponent();
DoSomething();
}
private void DoSomething()
{
// Code that was originally in Button_1_Click
}
private void Button_1_Click(object sender, EventArgs e)
{
DoSomething();
}
Call Button_1_Click directly from the form constructor:
public Membershipform()
{
InitializeComponent();
Button_1_Click(null, EventArgs.Empty);
}
I am really new to programming and currently working on a C# Windows Forms application.
The problem is the following:
I have a Form with different objects and controls like: tabpages, textboxes, timers, etc .
I also have a UserControl form which I load into one of the main Form's tabpages.
I would like to write a code into the UserControl , how can I manipulate element properties of the main Form.
For example: when I click on a button on the UserControl form It sets the main Form's timer.Enabled control to true.
It is possible to do this, but having the user control access and manipulate the form isn't the cleanest way - it would be better to have the user control raise an event and have the hosting form deal with the event. (e.g. on handling the button click, the form could enable/disable the timer, etc.)
That way you could use the user control in different ways for different forms if need be; and it makes it more obvious what is going on.
Update:
Within your user control, you can declare an event - In the button click, you raise the event:
namespace WindowsFormsApplication1
{
public partial class UserControl1 : UserControl
{
public event EventHandler OnButtonClicked;
public UserControl1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
EventHandler handler = OnButtonClicked;
// if something is listening for this event, let let them know it has occurred
if (handler != null)
{
handler(this, new EventArgs());
}
}
}
}
Then within your form, add the user control. You can then hook into the event:
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
userControl11.OnButtonClicked += userControl11_OnButtonClicked;
}
void userControl11_OnButtonClicked(object sender, EventArgs e)
{
MessageBox.Show("got here");
}
}
}
You may want to rethink what it is you are trying to accomplish. However, to answer your question, it can be done.
The best way to do it is to make a property in your UserControl called MainForm:
public Control MainForm {
get;
set;
}
Then, in your MainForm's Load event, set the property to itself:
userControl1.MainForm = this;
Finally, in your user control, set the MainForm's timer:
protected button_click(object sender, EventArgs e)
{
timerName = "timer1";
EnableTimer(timerName);
}
private void EnableTimer(timerName)
{
var timer = MainForm.Controls.FirstOrDefault(z => z.Name.ToLower().Equals(timerName.ToLower());
if (timer != null)
{
((Timer)timer).Enabled = true;
} else {
// Timer was not found
}
}
This is very simple. It's called events. On the user control you would expose an event with a EventHandler for the form to subscribe to.
public partial class MyUserControl : UserControl
{
/// You can name the event anything you want.
public event EventHandler ButtonSelected;
/// This bubbles the button selected event up to the form.
private void Button1_Clicked(object sender, EventArgs e)
{
if (this.ButtonSelected != null)
{
// You could pass your own custom arguments back to the form here.
this.ButtonSelected(this, e)
}
}
}
Now that we have the user control code we'll implement it in the form code. Probably in the constructor of the form you'll have some code like below.
MyUserControl ctrl = new MyUserControl();
ctrl.ButtonSelected += this.ButtonSelected_OnClick;
Finally in the form code you'll have a method that subscribed to the event like the below code that will set the Timer enabled to true.
private void ButtonSelected_OnClick(object sender, EventArgs e)
{
this.Timer1.Enabled = true;
}
And that's how you allow an event on a user control on a form set an object on the form.
You can set the timer1.Modifiers property to "internal" and access it with an instance to Form1:
form1.timer1.Enabled = true;
You need to have an instance of your class Form1, not the class itself. For example:
// INVALID
Form1.timer1.Enabled = true;
// VALID
var form1 = Form1.ActiveForm;
form1.timer1.Enabled = true;
But this is not a very clean way to do this, you would rather use events as described in NDJ's answer.
You need to put the below code,
(`userControl11.OnButtonClicked += userControl11_OnButtonClicked;`)
in a separate file in Visual Studio. The other file is called 'Form1.Designer.cs', and can be found in the Solution Explorer pane under
Form1 >> Form1.cs >> Form1.Designer.cs.
Hope this helps!
Ok, so I have Form1 calling Form2 in a way that allows me to access Form1's functions from Form2. Code Below...
Form1....
private void btnShowForm2_Click(object sender, EventArgs e)
{
frmForm2 tempDialog = new frmForm2(this);
tempDialog.ShowDialog();
}
Form2...
private frmForm1 _parent;
public frmForm2(frmForm1 frm1)
{
InitializeComponent();
_parent = frm1;
}
private void btnDoFunction_Click(object sender, EventArgs e)
{
_parent.DoProcess();
}
Now I have a new problem. I'm trying to update a status label of Form2, but the function that's processing the task at hand is in Form1. How can I change the label of Form2 from within the Function of Form1?
You can do so using delegate and event.
Make an event in form1 using a delegate
On progress in form1's process trigger the event.
put a handler to the form1 event in form2.
Extract the progress from that eventargs implemented object in the handler.
Show it in the lable in form2
This is a mess... form1 displays form2 which calls a method on form1 which updates the contents form2? Your question itself is easy (move the tempDialog variable to the form1 class instead of within this method - then you can use this during DoProcess to tweak whatever controls you want) but there is a serious maintainability problem here that you should step back and try to address.
If you really want to access frm2.lbl from frm1 then frm2.lbl must be public, this can be changed in the properties window of the label on Form2. (under modifiers I think)
private void btnDoFunction_Click(object sender, EventArgs e)
{
_parent.DoProcess();
}
(in form1)
public void DoProcess();
{
tempDialog.lable.Text = "hope this works";
}
I am passing data between 2 windows forms in c#. Form1 is the main form, whose textbox will receive the text passed to it from form2_textbox & display it in its textbox (form1_textbox).
First, form1 opens, with an empty textbox and a button, on clicking on the form1_button, form2 opens.
In Form2, I entered a text in form2_textbox & then clicked the button (form2_button).ON click event of this button, it will send the text to form1's textbox & form1 will come in focus with its empty form1_textbox with a text received from form2.
I am using properties to implement this task.
FORM2.CS
public partial class Form2 : Form
{
//declare event in form 2
public event EventHandler SomeTextInSomeFormChanged;
public Form2()
{
InitializeComponent();
}
public string get_text_for_Form1
{
get { return form2_textBox1.Text; }
}
//On the button click event of form2, the text from form2 will be send to form1:
public void button1_Click(object sender, EventArgs e)
{
Form1 f1 = new Form1();
f1.set_text_in_Form1 = get_text_for_Form1;
//if subscribers exists
if(SomeTextInSomeFormChanged != null)
{
SomeTextInSomeFormChanged(this, null);
}
}
}
FORM1.CS
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public string set_text_in_Form1
{
set { form1_textBox1.Text = value; }
}
private void form1_button1_Click(object sender, EventArgs e)
{
Form2 f2 = new Form2();
f2.Show();
f2.SomeTextInSomeFormChanged +=new EventHandler(f2_SomeTextInSomeFormChanged);
}
//in form 1 subcribe to event
Form2 form2 = new Form2();
public void f2_SomeTextInSomeFormChanged(object sender, EventArgs e)
{
this.Focus();
}
}
Now, in this case I have to again SHOW the form1 in order to automatically get the text in its textbox from form2, but I want that as I click the button on form2, the text is sent from Form2 to Form1, & the form1 comes in focus, with its textbox containing the text received from Form2.
I know this is a (really) old question, but hell..
The "best" solution for this is to have a "data" class that will handle holding whatever you need to pass across:
class Session
{
public Session()
{
//Init Vars here
}
public string foo {get; set;}
}
Then have a background "controller" class that can handle calling, showing/hiding forms (etc..)
class Controller
{
private Session m_Session;
public Controller(Session session, Form firstform)
{
m_Session = session;
ShowForm(firstform);
}
private ShowForm(Form firstform)
{
/*Yes, I'm implying that you also keep a reference to "Session"
* within each form, on construction.*/
Form currentform = firstform(m_Session);
DialogResult currentresult = currentform.ShowDialog();
//....
//Logic+Loops that handle calling forms and their behaviours..
}
}
And obviously, in your form, you can have a very simple click listener that's like..
//...
m_Session.foo = textbox.Text;
this.DialogResult = DialogResult.OK;
this.Close();
//...
Then, when you have your magical amazing forms, they can pass things between each other using the session object. If you want to have concurrent access, you might want to set up a mutex or semaphore depending on your needs (which you can also store a reference to within Session). There's also no reason why you cannot have similar controller logic within a parent dialog to control its children (and don't forget, DialogResult is great for simple forms)
I have a class that creates an instance of a form with several buttons. I have a function in this class which is meant to wait for the user to click one of the buttons and return different values depending on which button was pressed. I've read some of the stuff on using anonymous delegates for this, but I'm not sure how I would determine which specific button was pressed. My original approach was to create a custom event that takes the button number as parameter, and tacking an event handler onto that from my class, but again I am not sure how I would have that function return anything once I get into a delegate.
Is there any straightforward way of doing this?
PM
Assuming WinForms, there are a few approaches you could take. You could expose each button as a property on your form class and have the class the creates the form subscribe to the Click event for each button. For example,
In the Form class:
public class MyForm : Form
{
// form initialization, etc, etc.
public Button Button1
{
get { return button1; }
}
}
In the class that creates the form:
public class MyClass
{
public Form CreateForm()
{
var form = new MyForm();
form.Button1.Click += HandleButton1Clicked;
return form;
}
private void HandleButton1Clicked(object sender, EventArgs e)
{
// do whatever you need to do when Button1 is clicked
}
}
Alternatively, you could add a ButtonClicked event to the Form and determine which button was pressed that way. The form would subscribe to each of its button's Click events and fire ButtonClicked with button as the sender.
I'd probably go with the former since it would avoid having to write an if statement to determine which button was pressed.
Edited to adapt to the workflow in comments:
In that case, what you can do is have the Form take care of some of the details for you. For example, have the form record which button was pressed. If you show the form as a modal dialog, that will by design block the function that's created the form until it is dismissed.
public class MyForm : Form
{
// form initialization, etc, etc.
private Button button1;
private Button button2;
public MyForm()
{
InitializeComponent();
button1.Click += HandleButtonClicked;
button1.DialogResult = DialogResult.OK;
button2.Click += HandleButtonClicked;
button2.DialogResult = DialogResult.OK;
}
private void HandleButtonClicked(object sender, EventArgs e)
{
ButtonClicked = sender as Button;
}
public Button ButtonClicked
{
get; private set;
}
}
Calling code:
public class MyClass
{
public int GetValue()
{
var form = new MyForm();
if(form.ShowDialog() == DialogResult.OK) // this will block until form is closed
{
// return some value based on form.ButtonClicked
// adjust method's return type as necessary
}
else
{
// do something if the user closed the form without
// clicking on one of the buttons
}
}
}
Note that the HandleButtonClicked event handler is the same for both buttons, since the form is just storing which button was clicked.