I'm terribly new so I might be completely off track overall with what I'm trying to do.
I don't really know how to ask the question, my english is a bit rocky.
But I have 2 files one containing this:
frmMain.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class frmMain : Form
{
public frmMain()
{
InitializeComponent();
}
private void label1_Click(object sender, EventArgs e)
{
Class1 cls = new Class1();
cls.Visibility();
}
}
}
And another file containing this:
Class1.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace WindowsFormsApplication1
{
public partial class Class1
{
public void Visibility()
{
frmMain c = new frmMain();
c.label1.Visible = false;
}
}
}
What I'm trying to get is that when I'm running the program and clicking label1 I want it to disappear.
But it doesn't. I don't get any errors or anything.
Any help is appreciated :).
Thanks in advance.
First: Why are you trying to let the label on your mainform dissappear by using another class?
I would suggest the following:
private void label1_Click(object sender, EventArgs e)
{
label1.Visible = false;
}
I think the reason why your code isn't working is that inside the function Visibility() of Class1 you are creating a new frmMain and on that frmMain you are setting the visible property of label1 to false. So you are actually working with a different form.
You are instantiating a new, separate form. This means the label is being hidden.. but on a hidden form you have created.
You need to pass the current form instance into your other class:
public void Visibility(frmMain mainForm) {
mainForm.label1.Visible = false;
}
Then call it like this:
new Class1().Visibility(this);
What you're doing is you're creating a second instance of your window (which might not be obvious to you, as you're not displaying it). Then you are hiding the label in your second window. Probably not what you intended in the first place.
What you need to do is to pass a reference to your original form to the method you're calling, or (depending what you want to do) a reference to the control you need to hide:
in Class1:
public void Visibility(Control controlToHide)
{
controlToHide.Visible = false;
}
in frmMain.cs
new Class1.Visibility(this.label1)
few more comments:
Naming: do not use names like Class1, label1; I appreciate this is probably
just 'play around with' kind of code, but such names are completely
unreadable when you try to come back to your code later (or get
someone else to have a look)
Naming 2: try to name your methods to describe what they will do - HideControl, or HideLabel is much better than Visiblity
You may want to read some basic C# tutorials to learn about references, instances, parameters, etc.
Other than that, happy C#-ing :)
You do not want to let Class1 know about frmMain. Change it to something like this:
public class Class1
{
public bool GetVisibility()
{
return false;
}
}
And from your form, call it like this:
private void label1_Click(object sender, EventArgs e)
{
Class1 cls = new Class1();
this.Label1.Visible = cls.GetVisibility();
}
Your current implementation of Class1 initializes a new frmMain, hides that form's Label1, does not do anything with that instance (e.g. it does not Show() it) and then returns, not affecting the already instantiated and shown frmMain instance (the one you instantiate Class1 from).
You can change this by passing the label or even the form into Class1, but that is just bad design.
You may change your code this way:
public partial class FrmMain : Form
{
public frmMain()
{
InitializeComponent();
}
private void label1_Click(object sender, EventArgs e)
{
new Class1().Visibility(this);
}
public void Go()
{
this.label1.Visible = false;
}
}
Then
public partial class Class1
{
public void Visibility(FrmMain form)
{
form.Go();
}
}
You are setting the visibility of the label of another form (one that's not being displayed.
this line of code in the Visibility method creates a new object
frmMain c = new frmMain();
It's of the same type as the form being display, but it's a different object, that's not displayed. If you insert a line after the above
c.Show();
you should see the newly created form and also see that the label disappears
However there's a straight forward fix to your problem. Change the event handler to this
private void label1_Click(object sender, EventArgs e)
{
((Label)sender).Visible = false;
}
The sender object is the control that was clicked, and since the event is attached to the label it self. All you need to do is cast the sender to the type of a Label and then you can access the visible property. Alternatively you could do this:
private void label1_Click(object sender, EventArgs e)
{
this.label1.Visible = false;
}
That uses the current object (aka this) and gets the label from that object.
Related
I found this code in stackOF but it doesn't work at all and i can't fix that.
would you tell me what's wrong with this code?
using System.Windows.Forms;
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Button1_Click(object sender, EventArgs e)
{
Clipboard.SetText(textBox1.Text);
}
}
}
i think your problem because you named your program with same name of class that copy text to clipboard
take look at this code
using System.Windows.Forms;
namespace Clipboard
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
//Clipboard.SetText(textBox1.Text); This will not work if you named your namespace Clipboard !
System.Windows.Forms.Clipboard.SetText(textBox1.Text); // you should use this way to confirm you need to access to clipboard not your namespace
}
}
}
i named my program with same name of class(Clipboard)
and i have problem now because the compiler confusing between your program and class that copy a text
So the best way is to specify a unique name each time you create a program :)
There is a namespace conflict with your own. You can either explicitly use the exact Clipboard.SetText() method using the full declaration as per #WaleedKhaled's answer:
System.Windows.Forms.Clipboard.SetText(textBox1.Text);
or else the using statement at the top of your example to say something like:
using WinForms = System.Windows.Forms;
then your line would read:
WinForms.Clipboard.SetText(textBox1.Text);
My problem is, I can't invoke a message into the TextBox and I can't understand why.
There is a main class and a second class, both with call to the other one.
Where is my error?
using System;
using System.Windows.Forms;
namespace Class_Test___Invoke
{
public partial class MAINFORM : Form
{
public MAINFORM()
{
InitializeComponent();
_INVOKER = this;
}
private MAINFORM _INVOKER;
private static CLASS _CLASS = new CLASS();
private void button1_Click(object sender, EventArgs e)
{
_CLASS._MESSENGER();
}
public void _LOGGING(string _MESSAGE)
{
if (InvokeRequired)
{
_INVOKER.Invoke(new Action<string>(_LOGGING), new object[] { _MESSAGE });
textBox_ausgabe.AppendText(_MESSAGE);
return;
}
else textBox_ausgabe.AppendText(_MESSAGE);
}
}
}
namespace Class_Test___Invoke
{
class CLASS
{
private MAINFORM _MAINFORM = new MAINFORM();
public void _MESSENGER()
{
_MAINFORM._LOGGING("Test");
}
}
}
You are assuming that the _MAINFORM you create in the CLASS constructor is the same instance as the form where the button was clicked, which is not the case. You have a chicken-and-egg problem. Your form creates a CLASS, and the CLASS creates a form. So now you have two different forms. (or two different CLASS instances since you don't show how the first form or CLASS is created)
You need to "connect" the form and the class, either by passing the form to the constructor as a parameter or by some other means.
Finally, I would encourage you to do some research on best practices for class and member names. It's a bit disconcerting for a seasoned C# developer to see names in all caps and prefaced by underscores.
I'm working in VisualStudio.
I have this Form:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Test
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public void Form1_Load(object sender, EventArgs e)
{
}
public static int signal = 0;
public void button1_Click(object sender, EventArgs e)
{
}
}
}
And this User Control:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Test
{
public partial class UserControl1 : UserControl
{
public UserControl1()
{
InitializeComponent();
if (Form1.signal == 1)
{
MessageBox.Show("Signal received!", "Atention!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
}
private void UserControl1_Load(object sender, EventArgs e)
{
}
}
}
I bust my head to try to display the 'MessageBox' from 'UserControl1' when 'button1' from 'Form1' is clicked. Basically, I want to change the value of 'signal' to 1 when the 'button1' is pressed. I'm newbie but I'm pressed by time here so a good help will be very welcome. Any ideas? Thank you!
The button1_Click is the event that is going to be triggered when you click on the button from the Form.
Either create an event like another user suggested, or refer to this question and create a custom message box with your UserControl as its content.
When your UserControl is loaded it sees Form1.signal as 0 since you initialized it with that value. Your UserControl1 will never be aware of the change on Form1.
What you need to do is make listener function in UserControl1 that will be triggered, let's say every 10milliseconds and that will check if Form1.signal == 1.
Check Interval library for that, and I suggest you find time to learn a bit of C#. The language is awesome.
The best way to deal with communication between containers is to implement an observer class
The observer pattern is a software design pattern in which an object, called the subject, maintains a list of its dependents, called observers, and notifies them automatically of any state changes, usually by calling one of their methods.
(wikipedia)
the way i do this is creating an Observer class:
1 public delegate void dlFuncToBeImplemented(int signal);
2 public static event dlFuncToBeImplemented OnFuncToBeImplemented;
3 public static void FuncToBeImplemented(int signal)
4 {
5 OnFuncToBeImplemented(signal);
6 }
so basically: first line says that there would be a function that somebody else will implement
second line is creating an event that occur when the delegated function will call
and the third line is the creation of the function that calls the event
so in your UserControl you should add a function like this:
private void ObserverRegister()//will contain all observer function registration
{
Observer.OnFuncToBeImplemented += Observer_OnFuncToBeImplemented;
/*and more observer function registration............*/
}
void Observer_OnFuncToBeImplemented(int signal)//the function that will occur when FuncToBeImplemented(signal) will call
{
MessageBox.Show("Signal received!", "Atention!", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
and in your Form you should do something like:
public static int signal = 0;
public void button1_Click(object sender, EventArgs e)
{
Observer.FuncToBeImplemented(signal);//will call the event in the user control
}
and now, you can register this function to a whole bunch of other controls and containers and they will all get the signal
I hope this would help :)
newbie question :(
I'm making a program using windows forms and i have a lot of small methods like this
private void label1_Click(object sender, EventArgs e)
{
textBox1.Select();
}
private void label13_Click(object sender, EventArgs e)
{
textBox13.Select();
}
private void radioButton1_CheckedChanged(object sender, EventArgs e)
{
plotGraph(prostokat);
}
in the Form1.cs file and to make the code more transparent, I would like to move these small methods out somewhere to an external file (class?) but I don't really know how to do this. If they were normal methods I would just make a class and create an object of that class and just call the methods using that object but these are functions that "happen" when a user action is performed i.e. a textbox is clicked, so I'm not sure how to make this work.
It is possible to create an extra partial class (separated file) for your Form1 and place your cluttering methods there.
Or you could collapse them with #region
#region UI Handlers
#endregion
The perfect solution would be using some kind of MVVM for WinForms. In that case in your ViewModel you can implement your business logic separately from the code-behind.
Check out this:
https://www.codeproject.com/articles/364485/mvvm-model-view-viewmodel-patte
Hope it helps!
Have a look at your Form class subsection. It most cases it is still a partial class. Create a new .cs file in the same subsection in your project and add another partial form class to it.
You can find additional information here:
Partial Classes and Methods
Sure, you can add a new class to your project (right-click the project in Solution Explorer --> Add Class --> ) and put your methods there. Then you will need to hook the methods up to the controls in code:
I added a static class called "Form Methods" and put a method in there for label1 Click event:
static class FormMethods
{
public static void label1_Click(object sender, EventArgs e)
{
Label label = (Label) sender;
// Try to find the textbox through the label's parent form
TextBox textBox = (TextBox) label.Parent.Controls.Find("textBox1", true).First();
if (textBox != null)
{
textBox.Select();
}
}
}
Then in the Form Designer code, you can hook up the event:
this.label1.Click += new System.EventHandler(FormMethods.label1_Click);
Alternatively, you can make the class part of your original form class, and it will still be a separate file. If you want to do this, you can then make your event a private non-static method, and you would change the class definition to a public partial class:
public partial class Form1 // <-- This used to be: static class FormMethods
{
// This used to be: public static void label1_Click
private void label1_Click(object sender, EventArgs e)
{
. . .
And then hooking up the event looks like:
this.label1.Click += new System.EventHandler(label1_Click);
You can create any number of partial class files mimicking your original and group methods inside as your functionally needs - however, you won't be able to use the designer to directly navigate to your callbacks. That is, if you double click a graphic element or click an event of a graphic element you will have an unexpected behavior: in both cases you will have an event handler generated in your first partial and a hook created to that . . . so you can't directly navigate to those handlers anymore, and you need to go trough your partial files looking for their definitions.
Use partial to split C# code like this.
public partial class Employee
{
public void DoWork()
{
}
}
public partial class Employee
{
public void GoToLunch()
{
}
}
I'm trying to write my first program in C# without the use of a tutorial. To ensure that I adopt from the start good coding practices, I want to create each class in an different .cs file. However, I'm running into some troubles when trying to access the elements of the program in such an .cs file.
For example, I have an Form1.cs with an Label and a Start button. When clicking on the start button, a text should appear in the Label. So:
In Form1.cs I have:
namespace TestProgram
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void startButton_Click(object sender, EventArgs e)
{
WriteToLabel message = new WriteToLabel();
message.WelcomeMessage();
}
}
}
And in my separate WriteToLabel.cs file:
namespace TestProgram
{
public class WriteToLabel
{
public void WelcomeMessage()
{
Form1 myForm = new Form1();
//myForm.. --> myForm doesn't have an 'outputLabel'?
outputLabel.Text = "Welcome!"; // This returns an error: 'The name outputLabel does not exits in the current context'.
}
}
}
'outputLabel' is the (Name) I've given the label, and this is in accordance to the name in Form1.Designer.cs.
Both files are using the same components such as 'using System';.
However, from my WriteToLabel.cs file I can't seem to access the Form which holds my program. I did manage to succeed to create different .cs files in an Console Application, which only added to my confusion. So, I have two questions:
First, how can I access the Form from a separate class (i.e. not an partial class) in a separate file?
Second, is this the good way to do it, or is it inefficient to create multiple instances of different classes?
Any thoughts or ideas are highly welcome,
Regards,
The designer automatically creates controls as private fields, because of that your WriteToLabel class can't access it. You need to change that.
Also a good start would be to change the class to something like that:
namespace TestProgram
{
public class WriteToLabel
{
Form1 form;
public WriteToLabel(Form1 form)
{
this.form = form;
}
public void WelcomeMessage()
{
//Form1 myForm = new Form1();
//myForm.. --> myForm doesn't have an 'outputLabel'?
form.outputLabel.Text = "Welcome!";
}
}
}
You're actually instantiating a new instance of Form1, whereas you need to pass in a reference to your existing instance:
public void WelcomeMessage(Form1 form)
{
form.outputLabel.Text = "Welcome";
}
You also need to ensure that outputLabel is a public (or internal) property/field of Form1 so you can set the value accordingly. Then the calling code is slightly different:
private void startButton_Click(object sender, EventArgs e)
{
WriteToLabel message = new WriteToLabel();
message.WelcomeMessage(this);
}
You need to make sure that Form1.outputLabel has public or internal visibility.
You only need something like a LabelWriter class if the class is going to share a significant amount of state or private methods. If all you have is a bunch of methods that set properties on separate objects, you might as well just keep it as a method on the same object (in this case the Form1 object):
void startButton_Click(object sender, EventArgs e)
{
displayWelcomeMessage();
}
void displayWelcomeMessage()
{
this.outputLabel = "Welcome!";
}