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);
}
Related
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.
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!
Im making a userControl named [File_Manager] and i was wondering if i can add a button to this custom control that i can set its job later after adding this custom control to another form .. something like
File_Manager fManager = new File_Manager();
fManager.SetFreeButtonJob( MessageBox.Show("Hello") ); // something like this.
then whenever user press that button .. the messageBox shows up.
So.. Is it possible to do that?
thanks in advance.
Sure you can. Just attach the buttons click handler to the action you pass in.
fManager.SetFreeButtonJob(() => MessageBox.Show("Hello"));
private void SetFreeButtonJob(Action action)
{
button1.Click += (s,e) => action();
}
Just note that passing in the Action breaks the encapsulation of user control though. You should probably do something like SetFreeButtonJob(Jobs.SayHello); and put the knowledge of what to do inside the control.
Create a custom event for your UserControl and fire it when your Button is clicked. You can then attach an event handler to the custom event in your Form. Or you can just raise the UserControl's Click Event when your Button is clicked.
public delegate void CustomClickEventHandler(object sender, EventArgs e);
public partial class buttonTest : UserControl
{
public event CustomClickEventHandler CustomClick;
public buttonTest()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
CustomClick(sender, e);
}
}
and in your Form
public Form1()
{
InitializeComponent();
buttonTest1.CustomClick +=new CustomClickEventHandler(userControl1_ButtonClick);
}
private void userControl1_ButtonClick(object sender, EventArgs e)
{
MessageBox.Show("Hello");
}
Or as my second option try.
private void button2_Click(object sender, EventArgs e)
{
OnClick(e);
}
and in your Form subscribe to the UserControl's Click event.
buttonTest1.Click +=new EventHandler(buttonTest1_Click);
private void buttonTest1_Click(object sender, EventArgs e)
{
MessageBox.Show("Hello Again");
}
I have a main parent winform in which I have implemented some features and that have a number of child windows. Now I want the functionality I have implemented to run also on the child windows.
For instance, in the parent window I am moving an image on the selection of a checkbox. Now, if this checkbox is checked then the image should also move on the all other child windows.
Note: The image moving on the parent window should disapper and should only show on the opend dialogue or child window.
Please suggest if it is possible.
Try using events.
Create an event for the parent form called ImageMoved.
The child forms should subscribe to this event, and when you move the image, you raise the event, then the child forms will know to do their thing.
Lots of different ways to do this. Simple example:
public partial class Form1 : Form {
public event EventHandler ImageMoved;
private void OnImageMoved() {
if (ImageMoved != null)
ImageMoved(this, new EventArgs());
}
private void button1_Click(object sender, EventArgs e) {
OnImageMoved();
}
private void button2_Click(object sender, EventArgs e) {
Form2 f2 = new Form2(this);
f2.Show();
}
}
Then your child forms could look something like this:
public partial class Form2 : Form {
public Form2(Form1 parentForm) {
InitializeComponent();
parentForm.ImageMoved += new EventHandler(parentForm_ImageMoved);
}
void parentForm_ImageMoved(object sender, EventArgs e) {
MessageBox.Show("Image moved");
}
}
You could also create your own EventArgs class if you want to pass more information, such as which image, etc.
I have a windows form called FormMain in ClientForms project. Now this(FormMain) form opens another form called FormScheduler in Scheduling project.
Now, I want to send a message back to FormMain when a button_click method event is triggered in FormScheduler.
My solution creates a circular dependency. Is there another way, like using delegates ?
Use events.
In your form FormScheduer add a button and the following code:
public event EventHandler ButtonClicked;
private void button1_Click(object sender, EventArgs e) {
if (ButtonClicked != null) {
ButtonClicked(this, EventArgs.Empty);
}
}
In your FormMain, instantiate and display your FormScheduer form like this:
var form = new FormScheduer();
// Listen for the ButtonClicked event...
form.ButtonClicked += form__ButtonClicked;
form.Show();
Your form_ButtonClicked method on FormMain will be called when the button on FormScheduler is clicked:
void form__ButtonClicked(object sender, EventArgs e) {
Console.WriteLine("clicked");
}