Develop Reference

Struggling to add to ListBox

So I'm making this small program for my assignment at university and I'm finding it hard to add to my list in my form. Here is my code:
public partial class WorkOutBeam : Form
{
Check checkLib;
public BindingList<ListBox> list;
public WorkOutBeam()
{
InitializeComponent();
}
public void StartForm(object sender, EventArgs e)
{
list = new BindingList<ListBox>();
listBox1.DataSource = list;
}
private void NewForce_Click(object sender, EventArgs e)
{
NewForceName forceItem = new NewForceName();
forceItem.Show();
}
public void AddToForceList(string name)
{
list.Items.Add(name);
}
}
NewForceName class below:
public partial class NewForceName : Form
{
public WorkOutBeam workOutBeam;
public NewForceName()
{
InitializeComponent();
}
private void OkButton_Click(object sender, EventArgs e)
{
if (NewForceNames.Text != "")
{
ReferToLibs();
workOutBeam.AddToForceList(NewForceNames.Text);
Close();
}
}
private void ReferToLibs()
{
workOutBeam = new WorkOutBeam();
}
private void NewForceName_Load(object sender, EventArgs e)
{
}
}
So I say to my program, "give me a new force." When it does, it initializes a new form of "NewForceName." I type into a text box and click 'Ok', this starts a public method shown below:
The list is a binding list which refers to the listBox as a data source. However the program tells me that the Items part is inaccessible due to its protection but I don't know how to add it as public. I tried looking in the properties of my listBox but to no avail.

Give this a shot:
public partial class WorkOutBeam : Form
{
Check checkLib;
// public BindingList<ListBox> list; // get rid of this for now
public WorkOutBeam()
{
InitializeComponent();
}
/*public void StartForm(object sender, EventArgs e)
{
list = new BindingList<ListBox>();
listBox1.DataSource = list;
}*/
private void NewForce_Click(object sender, EventArgs e)
{
NewForceName forceItem = new NewForceName(this); // pass a reference to this
// instance of WorkoutBeam
forceItem.Show();
}
public void AddToForceList(string name)
{
// we should do some more things here, but let's keep it simple for now
listBox1.Items.Add(name);
}
}
And
public partial class NewForceName : Form
{
public WorkOutBeam workOutBeam;
public NewForceName( WorkoutBeam beam ) // we take a WorkoutBeam instance as CTOR param!
{
InitializeComponent();
workoutBeam = beam;
}
private void OkButton_Click(object sender, EventArgs e)
{
if (!string.IsNullOrEmpty(NewForceNames.Text))
{
workOutBeam.AddToForceList(NewForceNames.Text);
Close();
}
}
// DO NOT create new WorkoutBeams every time. Use the original.
/*private void ReferToLibs()
{
workOutBeam = new WorkOutBeam();
}*/
}
Disclaimer: I did not address each and every problem in this code. This is just enough so that it should "work" as intended.

c# Get variable value from Form when value changed with timer in usercontrol

I have a usercontrol which have timer
public partial class Cumle : UserControl
{
private bool cond=false;
//Some Code....
private void timer2_Tick(object sender, EventArgs e)
{
//Some Code....
if(//some condition...)
cond=true;
}
}
I am working on windows form.I want to display a message box which shows me that cond is true.I want to make this stuff without using timer on Form.
public partial class Form1 : Form
{
//What I must write here?
}

As mentioned, you should use Events. I would go like this:
public partial class Cumle : UserControl
{
public event EventHandler ConditionChangedToTrue;
protected virtual void OnConditionChangedToTrue(EventArgs e)
{
if (ConditionChangedToTrue != null)
ConditionChangedToTrue(this, e != null ? e : EventArgs.Empty);
}
private void timer2_Tick(object sender, EventArgs e)
{
//Some Code....
if (true) // add your condition
{
cond = true;
OnConditionChangedToTrue(null);
}
}
}
public partial class Form1 : Form
{
private Cumle cumle = new Cumle();
public Form1()
{
InitializeComponent();
cumle.ConditionChangedToTrue+= Cumle_ConditionChangedToTrue;
}
private void Cumle_ConditionChangedToTrue(object sender, EventArgs e)
{
// add your event handling code here
throw new NotImplementedException();
}
}

You need to add a public event to your UserControl, and subscribe to it from your main form.
Something like this should do it:
public partial class Cumle : UserControl
{
public event Action<bool> ConditionChanged = delegate {};
private bool cond=false;
//Some Code....
private void timer2_Tick(object sender, EventArgs e)
{
//Some Code....
if(//some condition...)
{
cond=true;
ConditionChanged(cond);
}
}
}
Then in your form:
public partial class Form1 : Form
{
void SubscribeToConditionChanged()
{
myUserControl.ConditionChanged += ShowDlg;
}
void ShowDlg(bool condition)
{
MessageBox.Show("....");
}
}

C#: String as parameter to event?

I have a GUI-thread for my form and another thread that computes things.
The form has a richtTextBox. I want the worker-thread to pass strings to the form, so that every string is displayed in the textbox.
Everytime a new string is generated in the worker thread I call an event, and this should now display the string.
But I don't know how to pass the string! This is what I tried so far:
///// Form1
private void btn_myClass_Click(object sender, EventArgs e)
{
myClass myObj = new myClass();
myObj.NewListEntry += myObj_NewListEntry;
Thread thrmyClass = new Thread(new ThreadStart(myObj.ThreadMethod));
thrmyClass.Start();
}
private void myObj_NewListEntry(Object objSender, EventArgs e)
{
this.BeginInvoke((MethodInvoker)delegate
{
// Here I want to add my string from the worker-thread to the textbox!
richTextBox1.Text += "TEXT"; // I want: richTextBox1.Text += myStringFromWorkerThread;
});
}
///// myClass (working thread...)
class myClass
{
public event EventHandler NewListEntry;
public void ThreadMethod()
{
DoSomething();
}
protected virtual void OnNewListEntry(EventArgs e)
{
EventHandler newListEntry = NewListEntry;
if (newListEntry != null)
{
newListEntry(this, e);
}
}
private void DoSomething()
{
///// Do some things and generate strings, such as "test"...
string test = "test";
// Here I want to pass the "test"-string! But how to do that??
OnNewListEntry(EventArgs.Empty); // I want: OnNewListEntry(test);
}
}

Like this
public class NewListEntryEventArgs : EventArgs
{
private readonly string test;
public NewListEntryEventArgs(string test)
{
this.test = test;
}
public string Test
{
get { return this.test; }
}
}
then you declare your class like this
class MyClass
{
public delegate void NewListEntryEventHandler(
object sender,
NewListEntryEventArgs args);
public event NewListEntryEventHandler NewListEntry;
protected virtual void OnNewListEntry(string test)
{
if (NewListEntry != null)
{
NewListEntry(this, new NewListEntryEventArgs(test));
}
}
}
and in the subscribing Form
private void btn_myClass_Click(object sender, EventArgs e)
{
MyClass myClass = new MyClass();
myClass.NewListEntry += NewListEntryEventHandler;
...
}
private void NewListEntryEventHandler(
object sender,
NewListEntryEventArgs e)
{
if (richTextBox1.InvokeRequired)
{
this.Invoke((MethodInvoker)delegate
{
this.NewListEntryEventHandler(sender, e);
});
return;
}
richTextBox1.Text += e.Test;
}
I've taken the liberty of making the NewListEntryEventArgs class immutable, since that makes sense. I've also partially corrected your naming conventions, simplified and corrected where expedient.

You need to create a new class by inheriting off EventArgs.

Create your own version of the EventArgs.
Do it like this:
public class MyEventArgs : EventArgs
{
public string MyEventString {get; set; }
public MyEventArgs(string myString)
{
this.MyEventString = myString;
}
}
Then in your code replace the EventArgs with MyEventArgs and create an MyEventArgs object with your string in it.
Then you can access it by using the MyEventArgs instance .MyEventString.
So you would do something like this:
///// myClass (working thread...)
class myClass
{
public event EventHandler NewListEntry;
public void ThreadMethod()
{
DoSomething();
}
protected virtual void OnNewListEntry(MyEventArgs e)
{
EventHandler newListEntry = NewListEntry;
if (newListEntry != null)
{
newListEntry(this, e);
}
}
private void DoSomething()
{
///// Do some things and generate strings, such as "test"...
string test = "test";
OnNewListEntry(new MyEventArgs(test));
}
}
And in your form:
private void myObj_NewListEntry(Object objSender, MyEventArgs e)
{
this.BeginInvoke((MethodInvoker)delegate
{
// Here I want to add my string from the worker-thread to the textbox!
richTextBox1.Text += e.MyEventString;
});
}

In general you need to inherit EventArgs and add a string property, and then make your event of type EventHandler<YourEventArgs>, but that is a classic case for the BackgroundWorker.
Sample here:
http://msdn.microsoft.com/en-us/library/cc221403(v=vs.95).aspx
and here:
C# backgroundWorker reports string?

Moq - mock.Raise should raise event in tested unit without having a Setup

I have a presenter class, that attaches an event of the injected view.
Now I would like to test the presenter reacting correctly to the event.
This is the view interface IView:
public interface IView
{
event EventHandler MyEvent;
void UpdateView(string test);
}
This is the view implementing IView:
public partial class MyView : IView
{
public event EventHandler MyEvent;
public MyView()
{
this.combo.SelectedIndexChanged += this.OnSelectedIndexChanged;
}
public void UpdateView(string test)
{
this.textBox.Text = test;
}
private OnSelectedIndexChanged(Object sender, EventArgs e)
{
if (this.MyEvent != null)
{
this.MyEvent(sender, e);
}
}
}
This is the presenter under test:
public class MyPresenter
{
private IView _view;
public MyPresenter(IView view)
{
this._view = view;
this._view.MyEvent += this.OnMyEvent;
}
private void OnMyEvent(Object sender, EventArgs e)
{
this._view.UpdateView();
}
}
This is the test fixture testing MyPresenter:
[TestClass]
public class MyPresenterFixture()
{
private MyPresenter testee;
private Mock<IView> mockView;
[TestMethod]
public void ShouldReactOnMyEvent()
{
// arrange
this.mockView = new Mock<IView>(MockBehavior.Strict);
this.testee = new MyPresenter(this.mockView.Object);
// act
this.mockView.Raise(mock => mock.MyEvent += null); // this does not fire
// assert and verify
this.mockView.Verify(mock => mock.UpdateView(It.IsAny<string>());
}
}
I am using Moq 4. Is it possible to do what I want?

Don't you need to pass the argument? Your event signature is EventHandler, which is
(object sender, EventArgs e).
this.mockView.Raise(mock => mock.MyEvent += null, new EventArgs());
I've never used the overload you've specified here... it doesn't seem correct, though.

You've declared UpdateView() as accepting a string, but your presenter invocation does not have a string argument (or default):
Invocation:
private void OnMyEvent(Object sender, EventArgs e)
{
this._view.UpdateView();
}
Declaration:
public void UpdateView(string test)
{
this.textBox.Text = test;
}
Verification:
mockView.Verify(mock => mock.UpdateView(It.IsAny<string>());
FWIW, I think the event in your view is a bit cumbersome, a simple change would be to:
public interface IView
{
void UpdateText(string test);
}
public class MyPresenter
{
private readonly IView _view;
public MyPresenter(IView view)
{
_view = view;
}
private void SelectItem(string item)
{
_view.UpdateText(item);
}
}
public partial class MyView : IView
{
private readonly MyPresenter _presenter;
public MyView()
{
_presenter = new MyPresenter(this);
combo.SelectedIndexChanged += OnSelectedIndexChanged;
}
public void UpdateText(string test)
{
textBox.Text = test;
}
private OnSelectedIndexChanged(Object sender, EventArgs e)
{
_presenter.SelectItem(combo.SelectedItem);
}
}
Then you could just verify the interaction with the view without having an additional event to deal with:
presenter.SelectItem("Burrito!");
mockView.Verify(mock => mock.UpdateView("Burrito!");

Delegates and events?

This question is related to c#.The scenario is that when i click the button the operations like File reading,Data manipulation ,and file dumping are going to be happened.After the completion of each operation i will update the status(i.e,File reading completed,data manipulation completed) in the label which is in UI(FORM-frmTesting)
The button click event is
namespace frmTesting
{
public partial class Form1 : Form
{
private void button1_Click_1(object sender, EventArgs e)
{
class1 l_objClass1 = new class1();
l_objClass1.DoOperation();
}
}
public class class1
{
public int DoOperation()
{
ReadTextFile();
ParsingData();
SaveTextFile();
return 0;
}
private int ReadTextFile()
{
//Read the text File
return 0;
}
private int ParsingData()
{
// Data manipulation
return 0;
}
private int SaveTextFile()
{
// save the file
return 0;
}
}
}
Is it possible by using Delegates and Events....if you have any queries plz revert back me

You'll have to modify class1 to broadcast events that other classes can listen to:
public class class1
{
// Not necessary, but will allow you to add custom EventArgs later
public delegate void StatusChangedEventHandler(object sender, EventArgs e);
public event StatusChangedEventHandler FileRead;
public event StatusChangedEventHandler FileParsed;
public event StatusChangedEventHandler FileSaved;
public int DoOperation()
{
ReadTextFile();
ParsingData();
SaveTextFile();
return 0;
}
private int ReadTextFile()
{
//Read the text File
OnFileRead(EventArgs.Empty);
return 0;
}
private int ParsingData()
{
// Data manipulation
OnFileParsed(EventArgs.Empty);
return 0;
}
private int SaveTextFile()
{
// save the file
OnFileSaved(EventArgs.Empty);
return 0;
}
protected virtual void OnFileRead(EventArgs e)
{
if(FileRead != null)
FileRead(this, e);
}
protected virtual void OnFileParsed(EventArgs e)
{
if(FileParsed != null)
FileParsed(this, e);
}
protected virtual void OnFileSaved(EventArgs e)
{
if(FileSaved != null)
FileSaved(this, e);
}
}
And then have your form listen for those events and change its label appropriately:
public partial class Form1 : Form
{
private void button1_Click_1(object sender, EventArgs e)
{
class1 l_objClass1 = new class1();
l_objClass1.FileRead +=
delegate { lblStatus.Text = "File Read..."; };
l_objClass1.FileParsed +=
delegate { lblStatus.Text = "File Parsed..."; };
l_objClass1.FileSaved +=
delegate { lblStatus.Text = "File Saved..."; };
l_objClass1.DoOperation();
}
}

The short answer is yes. You add events to class1 and add handlers to Form1 with the appropriate logic. Below is a sample of how to do this
public partial class Form1 : Form
{
private void button1_Click_1(object sender, EventArgs e)
{
class1 obj = new class1();
obj.FileReadingComplete += HandleFileReadingComplete;
obj.DataManipulationComplete += HandleDataManipulationComplete;
obj.DoOperation();
obj.FileReadingComplete -= HandleFileReadingComplete;
obj.DataManipulationComplete -= HandleDataManipulationComplete;
}
private void HandleFileReadingComplete(object sender, EventArgs args){
//code here
}
private void HandleDataManipulationComplete(object sender, EventArgs args)
{
//code here
}
}
public class class1
{
public event EventHandler FileReadingComplete;
public event EventHandler DataManipulationComplete;
public int DoOperation()
{
ReadTextFile();
OnFileReadingComplete();
ParsingData();
OnDataManipulationComplete();
SaveTextFile();
return 0;
}
private int ReadTextFile()
{
//Read the text File
return 0;
}
private int ParsingData()
{
// Data manipulation
return 0;
}
private int SaveTextFile()
{
// save the file
return 0;
}
public void OnFileReadingComplete()
{
EventHandler handler = FileReadingComplete;
if (handler != null) {
handler(this, EventArgs.Empty);
}
}
public void OnDataManipulationComplete()
{
EventHandler handler = DataManipulationComplete;
if (handler != null) {
handler(this, EventArgs.Empty);
}
}
}