How to fix multiple forms problem (CS7036) - c#

I have an application that sends information from two forms (Form 2 to Form 1) and I have a menu screen that enters Form 2 but when I try to open form two I get the error (CS7036). Basically, I have the error that says
"Error CS7036 There is no argument given that corresponds to the
required formal parameter 'incoming' of 'difficulty.difficulty(Easy)"
(difficulty is "form 2" and easy is "form 1"
FROM Menu
private void btnStart_Click(object sender, EventArgs e)
{
this.Close();
difficulty diff = new difficulty();
diff.ShowDialog();
}
FROM DIFFICULTY
public partial class difficulty : Form
{
public difficulty(Easy incoming)
{
InitializeComponent();
}
private void btnEasy_Click(object sender, EventArgs e)
{
this.Close();
Easy easy = new Easy();
easy.ShowDialog();
}
}
How do I make it work so I can enter the menu then difficulty then easy without any errors? Any help appreciated.

You haven't passed in the parameter you added to your constructor while instantiating the class.
Here's a fixed version of your code:
private void btnStart_Click(object sender, EventArgs e) {
//use whatever easy you have here
Easy easy = new Easy();
difficulty diff = new difficulty(easy);
diff.ShowDialog();
this.Hide();
}
You need to have an Easy class created beforehand to pass in. And if you want to use that instance in the class, you can do this:
public partial class difficulty : Form {
private Easy easy;
public difficulty(Easy incoming)
{
easy = incoming;
InitializeComponent();
}
private void btnEasy_Click(object sender, EventArgs e) {
....
}
}
Then in any of the class functions, reference the easy variable to get data.

Related

Winforms new form instance in class not working

I am trying to maximize a form from a class file but when I make a new instance of the form in the class nothing happens. I have spent a long time searching for an answer and did not find anything. This is the code I have in the class.
public void maxForm() //code from the class
{
Options options = new Options();
options.WindowState = FormWindowState.Maximized; //not working
}
This is the code I have in the form.
private void button1_Click(object sender, EventArgs e) //code from form
{
Class1 class = new Class1();
class.maxForm();
}
If I do the same code but for a different form it will work. It acts like its being blocked.
Don't you need to show form?
Options options = new Options();
options.WindowState = FormWindowState.Maximized;
options.Show();
when I make a new instance of the form
That's your problem right there. You don't want a new instance, you want the instance that already exists.
If your button1 is part of your Options form, then just do this:
private void button1_Click(object sender, EventArgs e) //code from form
{
WindowState = FormWindowState.Maximized;
}
Or if, as you say, you need to maximize it from a different class (why?), then you can do something like this:
public void maxForm(Options options) //code from the class
{
options.WindowState = FormWindowState.Maximized;
}
private void button1_Click(object sender, EventArgs e) //code from form
{
Class1 class = new Class1();
class.maxForm(this);
}

Add item to listview from another form

I've stomped with a problem I've spent some hours trying to solve, with my very limited knowledge.
I have a listview in my form1 called listMachine
And I have a method in form1.cs such as
private void máquinaToolStripMenuItem_Click(object sender, EventArgs e)
{
machinename open = new machinename();
open.Show();
}
machinename.cs is another form, and I use that method to open my other form, with an object called open.
the machinename button is a simple form which just serves as an input receiver, it asks a name, we have to type it into the textbox, press a button and it receives the input.
This is the code that runs when you press the button
public void buttonAceitarnome_Click(object sender, EventArgs e)
{
if (textBoxnomenova.TextLength == 0)
{
toolTipEmptyname.Show("O nome da máquina não pode estar vazio", textBoxnomenova);
}
else
{
Variables.var = textBoxnomenova.Text;
//MessageBox.Show(Variables.var); debug purpose, the messagebox does carry variables.var text
obj.listMachine.Items.Add(Variables.var); //If I change the variables.var to "test" it will NOT add the item.
this.Close();
}
}
Also, I forgot to mention my Variables.cs class, I created it because it was the only way I found to pass variables from a class to another (machinename.cs to form1.cs), but still, the items are not added into the listview.
This is my variables.cs code
public static class Variables
{
public static string var;
}
The comments I added to the code also give you some extra debug info..
I didn't want to ask for online help, but couldn't solve this on my own :(
If I were you, I would first remove the Variables class.
Then, you'r first form/class is called obj.cs, am I right? Or is it form1.cs?
I made it look like this:
public partial class obj : Form
{
public static string text; //This is a variable that can be reached from
public obj()
{
InitializeComponent();
}
private void máquinaToolStripMenuItem_Click(object sender, EventArgs e)
{
machinename open = new machinename();
open.ShowDialog(); //I put ShowDialog instead of Show
addItem(); //This method is called when the showed dialog is closed (machinename.cs)
}
private void addItem()
{
listMachine.Items.Add(text);
}
}
and the machinename.cs class like this:
public partial class machinename : Form
{
public machinename()
{
InitializeComponent();
}
private void buttonAceitarnome_Click(object sender, EventArgs e) //This one can be private
{
if (textBoxnomenova.TextLength == 0)
{
//Something here
}
else
{
obj.text = textBoxnomenova.Text; //Initializing the public static variable
this.Close(); //Closes the form, next step will be to run the method in obj.cs
}
}
}
If I understood your question correctly, you wanted to add an item to the ListView called "listMachine" via a button in the form "machinename.cs". This code will do that. I hope it helps you.
Change the click event from private to protected.
protected void máquinaToolStripMenuItem_Click(object sender, EventArgs e)

How to call mainform method in another form in usercontrol C#

I am working with windowsFrom in c#. I am trying to call mainfrom method in one of the from in user control.
I have mainfrom like this
namespace Project
{
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}
public void TempCommand()
{
StartTemp();
}
}
}
I have the button click in the user control. When i click that button then it will open another form. I have the code like this in the user control.
private TempCalib _tempCalib = new TempCalib();
private void calibBtn_Click(object sender, EventArgs e)
{
_tempCalib.Show();
}
it will open another from and i have one button in that from. I need to call mainfrom method when i click "Ok" button in this from.
namespace Project
{
public partial class TempCalib : Form
{
public TempCalib()
{
InitializeComponent();
}
private void OkButton_Click(object sender, EventArgs e)
{
// I need to call the mainfrom "TempCommand" method here.
this.Hide();
}
}
}
Can anyone help me how to do this.
Thanks.
Quick answer
Just add a reference to the primary form in your secondary form:
public partial class TempCalib : Form
{
private MainForm _main
public TempCalib(MainForm main) : this()
{
_main = main;
}
/// Other stuffs
}
Then assign value when you construct your secondary form:
private TempCalib _tempCalib;
private void calibBtn_Click(object sender, EventArgs e)
{
if (_tempCalib == null)
_tempCalib = new TempCalib(this);
_tempCalib.Show();
}
If calibBtn_Click isn't inside MainForm (but it's inside a UserControl on it) then you can replace _tempCalib initialization with:
_tempCalib = new TempCalib((MainWindow)FindForm());
You'll be then able to call the primary form:
private void OkButton_Click(object sender, EventArgs e)
{
_main.TempCommand();
this.Hide();
}
Notes: this is just one option, you may create a property to hold MainForm reference (so secondary form can be reused and it'll be more designer friendly) moreover TempCalib is not an UserControl but a Form (pretty raw but for an UserControl you may just check its parent Form and cast it to proper type).
Improvements
Such kind of references are often an alert. Usually UI components shouldn't not be so coupled and a public Form's method to perform something very often is the signal that you have too much logic in your Form. How to improve this?
1. DECOUPLE CONTROLS. Well a first step may be to decouple them a little bit, just add an event in TempCalib and make MainForm its receiver:
public partial class TempCalib : Form
{
public event EventHandler SomethingMustBeDone;
private void OkButton_Click(object sender, EventArgs e)
{
OnSomethingMustBeDone(EventArgs.Empty); / TO DO
this.Hide();
}
}
Then in MainForm:
private TempCalib _tempCalib;
private void calibBtn_Click(object sender, EventArgs e)
{
if (_tempCalib == null)
{
_tempCalib = new TempCalib();
_tempCalib.SomethingMustBeDone += _tempCalib_SomethingMustBeDone;
// In _tempCalib_SomethingMustBeDone you'll invoke proper member
// and possibly hide _tempCalib (remove it from OkButton_Click)
}
_tempCalib.Show();
}
2. DECOUPLE LOGIC FROM CONTROLS. UI changes pretty often, logic not (and when it changes probably isn't in parallel with UI). This is just the first step (now TempCalib isn't aware of who will use it). Next step (to be performed when too much things happen inside your form) is to remove this kind of logic from the form itself. Little example (very raw), keep TempCalib as before (with the event) and change MainForm to be passive:
public partial class MainForm : Form
{
public event EventHandler Calibrate;
protected virtual void OnCalibrate(EventArgs e)
{
// TODO
}
}
Now let's create a class to control the flow and logic:
public class MyTaskController
{
private MainForm _main;
private TempCalib _tempCalib;
public void Start()
{
_main = new MainForm();
_main.Calibrate += OnCalibrationRequested;
_main.Show(); // Or whatever else
}
private void OnCalibrationRequested(object sender, EventArgs e)
{
if (_tempCalib == null)
{
_tempCalib = new TempCalib();
_tempCalib.SomethingMustBeDone += OnSomethingMustBeDone();
}
_tempCalib.Show();
}
private OnSomethingMustBeDone(object sender, EventArgs e)
{
// Perform the task here then hide calibration window
_tempCalib.Hide();
}
}
Yes, you'll need to write much more code but this will decouple logic (what to do as response to an action, for example) from UI itself. When program grows up this will help you to change UI as needed keeping logic unaware of that (and in one well defined place). I don't even mention that this will allow you to use different resources (people) to write logic and UI (or to reuse logic for different UI, WinForms and WPF, for example). Anyway IMO the most obvious and well repaid benefit is...readability: you'll always know where logic is and where UI management is, no search, no confusion, no mistakes.
3. DECOUPLE LOGIC FROM IMPLEMENTATION. Again you have more steps to perform (when needed). Your controller is still aware of concrete types (MainForm and TempCalib). In case you need to select a different form at run-time (for example to have a complex interface and a simplified one or to use dependency injection) then you have to decouple controller using interfaces. Just an example:
public interface IUiWindow
{
void Show();
void Hide();
}
public interface IMainWindow : IUiWindow
{
event EventHandler Calibrate;
}
public interface ICalibrationWindow : IUiWindow
{
event EventHandler SomethingMustBeDone;
}
You could use a custom event that is declared in your UserControl. Then your form needs to handle this event and call the method you want to call. If you let the UserControl access your form, you are hard-linking both with each other which decreases reusability of your UserControl.
For example, in TempCalib:
public delegate void OkClickedHandler(object sender, EventArgs e);
public event OkClickedHandler OkClicked;
private void OkButton_Click(object sender, EventArgs e)
{
// Make sure someone is listening to event
if (OkClicked == null) return;
OkClicked(sender, e);
this.Hide();
}
in your mainform:
private void Mainform_Load(object sender, EventArgs e)
{
_tempCalib.OkClicked += CalibOkClicked;
}
private void CalibOkClicked(Object sender, EventArgs e)
{
StartTemp();
}
You create an event in your usercontrol and subscribe to this in the mainform.
That is the usual way.
Form1 Code:
UserControl1 myusercontrol = new UserControl1();
public void TabClose(Object sender,EventArgs e)
{
int i = 0;
i = tabControl1.SelectedIndex;
tabControl1.TabPages.RemoveAt(i);
}
private void Form1_Load(object sender, EventArgs e)
{
myusercontrol.Dock = DockStyle.Fill;
TabPage myTabPage = new TabPage();
myTabPage.Text = "Student";
myTabPage.Controls.Add(myusercontrol);
tabControl1.TabPages.Add(myTabPage);
myusercontrol.OkClick += TabClose;
}
UserControl1 Code:
public delegate void OkClickedHandler(Object sender, EventArgs e);
public partial class UserControl1 : UserControl
{
public event OkClickedHandler OkClick;
public UserControl1()
{
InitializeComponent();
}
private void button3_Click(object sender, EventArgs e)
{
if (OkClick == null) return;
OkClick(sender, e);
}
}
Try this:
From user control try this:
MainForm form = this.TopLevelControl as MainForm;
form.TempCommand();

Order of form_load method execution

I am creating a winforms application which uses Gmaps.net. I am unable to alter the order in which on Load methods are being called. For some reason the map_load is being called before the man_Load. Is there any way to change the order of this ?
If I can provide any more information to help just ask.
Thanks!
Dan.
public partial class main : Form
{
public main()
{
InitializeComponent();
}
private void main_Load(object sender, EventArgs e)
{
MessageBox.Show("main_load");
}
private void map_Load(object sender, EventArgs e)
{
MessageBox.Show("map_load");
}
}
It seems that you used the WinForms designer to create the map. The code behind is in the InitializeComponent() method and seems that the map is being loaded before the MainForm is loaded.
My recommendation is to create the map, once the MainForm has been loaded:
public partial class main : Form
{
public main()
{
InitializeComponent();
}
private void main_Load(object sender, EventArgs e)
{
Control map = CreateMap();
map.Docking = DockStyle.Fill;
this.Controls.Add(map);
}
private Control CreateMap()
{
// Create a new GMaps.NET object, intialize it and return
}
}
Hope it helps.

call variable from another form C#

I have a DataGridView in Form1 and I'm using this code to display another form called Generator:
private void button1_Click(object sender, EventArgs e)
{
Form gen = new Generator();
// Form gen = new Generator(Form this); //* I tried this but is not working *//
gen.Show();
}
In the Generator form I need to read or modify something in the datagridview which is in the Form1.
public partial class Generator : Form
{
public Form myForm;
public Generator()
{
InitializeComponent();
}
public Generator(Form frm)
{
myForm = frm;
}
private void button1_Click(object sender, EventArgs e)
{
myForm.mydatagridview.! // this is not working
}
}
How can I resolve this problem, so I can manipulate the DataGridView from the Generator form?
Form 1:
private void button1_Click(object sender, EventArgs e)
{
Form gen = new Generator(this.mydatagridview);
gen.Show();
}
Generator Form:
DataGridView _dataGridView;
public Generator(DataGridView dataGridView)
{
InitializeComponent();
this._dataGridView = dataGridView;
}
private void button1_Click(object sender, EventArgs e)
{
this._dataGridView...! // this will work
}
Things that you must do, and know (just tips, you are not forced to do these but I believe you will be a better programmer if you do! ;)
Always call InitializeComponent() in all form constructors. In your sample you didn't call it in one of the constructors.
C# knows only information of the type you have passed. If you pass a Form, then you only get Form properties (i.e. the properties of type Form), not the properties of your own form.
Try to encapsulate things. Do not pass a whole form to another form. Instead, pass things that you would like to use on the other form.
A few things are going on here.
You have to use the constructor of Generator that take in a form as a parameter.
You have to expose the datagridview as a public or internal property on the form that you will pass into Generator.
The normal Form class will not know about this property, so you should cast the variable appropriately.
You should call the default constructor of Generator when the other constructor is used to make sure everything is initialized correctly. See code sample below.
Something like this should work:
public class Generator
{
private MyForm myForm;
public Generator()
{
InitializeComponent();
}
public Generator(MyForm frm) : this() // DON'T FORGET THIS()
{
myForm = frm;
}
private void button1_Click(object sender, EventArgs e)
{
myForm.MyDataGridView... // Yay, it works!
}
}
public class MyForm : Form
{
public MyForm()
{
InitializeComponent(); // a datagridview is created here, say "datagridview1"
}
public DataGridView MyDataGridView
{
get { return datagridview1; }
}
}
And then in your button click event (which I assume is defined somewhere in MyForm):
private void button1_Click(object sender, EventArgs e)
{
Form gen = new Generator(this);
gen.Show();
}
The easiest way from there is to open the designer for the DataGridView (myDataGridView) on Form1 and set the Modifiers property from private to internal or public
This will let you call myForm.myDataGridView from the Generator form.

Categories

Resources