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Accessing textbox variables from another class

I have a windows form (c#). In the form, the user inputs some text and it then gets saved to an XML. Each time the solution starts, it reads the XML.
At first, I was just testing so I had a master class. Then I started creating different classes and run into a problem.
I can't access the values from the textboxes of the form from the other classes. There are a few other posts asking the same, but I couldn't manage to solve it.
This is what I have:
namespace Emailing
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
XmlController xc = new XmlController();
xc.readXml(); //reads the xml when starts
}
private void button1_Click(object sender, EventArgs e)
{
XmlController xc2 = new XmlController();
xc2.updateXml(); //updates the xmls when the users clicks a button
}
}
}
namespace Emailing
{
class XmlController
{
public void updateXml()
{
DataSet ds = new DataSet();
DataTable dt = new DataTable();
dt.TableName = "Server";
dt.Columns.Add("Server");
ds.Tables.Add(dt);
DataRow row = ds.Tables["Server"].NewRow();
row["Server"] = Form1.textBox6.Text;
ds.Tables["Server"].Rows.Add(row);
ds.WriteXml("Emailer.xml");
}
public void readXml()
{
DataSet ds = new DataSet();
ds.ReadXml("Emailer.xml");
Form1.textBox6.Text = ds.Tables["Server"].Rows[0][0].ToString();
}
}
}
I tried several things with no success.
From what I read, the "best" practice would be to create an interface. I tried but couldn't make it work.
I also tried creating a get set method for the textBox but couldn't make it work. I'm not sure where it should go.
Thanks for your time,

You have instantiated the XmlController class 2 times.
this means that you have 2 objects of the same class, but it are different objects.
what you should do is instantiate the class once and use this object also for the button_Click event (see code)
namespace Emailing
{
public partial class Form1 : Form
{
private XmlController xc;
public Form1()
{
InitializeComponent();
xc = new XmlController();
xc.readXml(); //reads the xml when starts
}
private void button1_Click(object sender, EventArgs e)
{
xc.updateXml(); //updates the xmls when the users clicks a button
}
}
}
however I do suggest you start experimenting with the MVVM pattern see: https://www.codeproject.com/Articles/165368/WPF-MVVM-Quick-Start-Tutorial

If you want to access something from "outside" of a class (the form is a class),
you need it to be Public.
Edit:
namespace Emailing
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
...
}
public string TextOfTextBox1 { get { return Textbox1.Text; } }
}
}
If you have, lets say a 'LoginForm',
You might want to add a property to fetch the given Username as public string UserName { get { return userNameTextBox.Text; } }
(same for the Password, Remmember me, Etc...)

Interface Event between two projects in one solution and Event Handlers

I have separated two projects in my solution because they each require libraries targeting different CPU.
In one of my project, I just have classes that respond to clicks (let's call it ProjectClick 64 bits libraries), the other one is a sort of UI with an MVVM implementation (ProjectUser 32 bits libraries).
The thing I am searching for is a way to let the ProjectUser know that the click has been performed by the ProjectClick, without the Project Click knowing anything else.
What I have tried so far
I have been scattering the web and books to understand a bit more about C#. From what I understood, to communicate, the best way is to create a Interface. I have been looking at this subject for an answer, and have been trying to implement a third project with an interface between the two.
Ok, here goes the code, (this is a purposely simplified code, I hope it is clear enough)
First the Interface (in a console application)
namespace LinkApplication
{
public interface IEvent
{
bool CompareClick { get; set; }
}
}
Then, the project clicking which is a wpf
namespace ProjectClick
public partial class MainWindow : Window, IEvent
{
public MainWindow()
{
try { InitializeComponent(); }
catch (Exception e)
{
Console.WriteLine(e.InnerException);
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
CompareClick = true;
}
private void Button_Leave(object sender, RoutedEventArgs e)
{
CompareClick = false;
}
}
Finally the UI
namespace ProjectUser
{
public partial class MainWindow : Window, IEvent, INotifyPropertyChanged
{
public MainWindow()
{
InitializeComponent();
this.WindowStartupLocation = WindowStartupLocation.CenterScreen; //start the window at the centre of the screen
DataContext = this;
}
public bool CompareClick { get; set; }
public bool ClickCheck
{
get { return CompareClick; }
set
{
if (value != CompareClick)
{
CompareClick = value;
OnPropertyChanged("ClickCheck");
}
}
}
You can see the realted Label here in the Window
<Label Content="{Binding ClickCheck}" HorizontalAlignment="Left" Margin="690,358,0,0" VerticalAlignment="Top"/>
Here, the value always stays at false, and I don't really understand the logic of the changing value. I am still learning, and I have seen several other ideas on the web like a custom EventHandler, but I don't really understand the implementation between two projects not knowing each others. I will be glad if someone could route me towards a possible solution, or a better way to perform.
Edit
I would preferably like to avoid referring the Project Click in the ProjectUser to keep the privileges of different CPU targeting. The other way around is not a problem.
Thank you for your kind answers.

I have been greatly advised and have looked into Inter Process Communication between instances. I have looked into different things but the most satisfying answer of all was on Omegaman's blog (bit thanks to this subject).
So basically, I have tried to avoid localhost information, thinking there would be a more straightforward solution. But since we have not thought of anything better, I think this is what I was looking for.
What I have found
So now, the solution here was to use a WCF service with NamedPipes. By creating a Sender and Receiver actions, the two process ProjectUser and ProjectClick never encounter each other directly. You have instead a pipe controlled by the WCF. You can see more details on the blog on how to communicate, I just adapted (without great change) what he did by changing the passing information.
One thing to note however
The processes cannot both start at the same time, and the receiver must start first to listen to the information coming through. Basically, the sender has to start afterwards.
I created two windows in WPF, and a WCFServiceLibrary. When the button is clicked, there is an incrementation, and it shows the number on the second screen.
A little bit of code
You can see a lot on Omegaman's blog, and I will just post what I have changed.
On the ProjectUser side, supposed to receive, the label is updated as follows
Receiver pipe = new Receiver();
public MainWindow()
{
InitializeComponent();
//this.WindowStartupLocation = WindowStartupLocation.CenterScreen; //start the window at the centre of the screen
DataContext = this;
pipe.Data += new PipeLink.PipeService.DataIsReady(DataBeingRecieved);
if (pipe.ServiceOn() == false)
MessageBox.Show(pipe.error.Message);
label1.Content = "Listening to Pipe: " + pipe.CurrentPipeName + Environment.NewLine;
}
void DataBeingRecieved(int data)
{
Dispatcher.Invoke(new Action(delegate()
{
label1.Content += string.Join(Environment.NewLine, data);
label1.Content += Environment.NewLine;
}));
}
On the ProjectClick side, supposed to send, the button click updates as follows
int i;
public MainWindow()
{
try { InitializeComponent(); }
catch (Exception e)
{
Console.WriteLine(e.InnerException);
}
i = 0;
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
int messages;
i++;
Stopwatch stoop = new Stopwatch();
stoop.Start();
messages = i;
try
{
PipeLink.Sender.SendMessage(messages);
stoop.Stop();
Console.WriteLine(stoop.ElapsedMilliseconds + " ms");
}
catch (Exception u)
{
Console.WriteLine(u);
}
}
The important part of the code, is the creation of the pipe itself, using NetNamedPipeBinding. This is where the whole communication will take place
You can see it in the PipeService code :
public class PipeService : IPipeService
{
public static string URI
= "net.pipe://localhost/Pipe";
// This is when we used the HTTP bindings.
// = "http://localhost:8000/Pipe";
#region IPipeService Members
public void PipeIn(int data)
{
if (DataReady != null)
DataReady(data);
}
public delegate void DataIsReady(int hotData);
public DataIsReady DataReady = null;
#endregion
}
What about the speed?
I was afraid simple data may take longer to arrive than on a simple click. I was mistaken : the first number took longer than the others because of the first connection, so about a second. But after that, for clicking about a 100 times, I had a, average of 10 ms (I know it is not significant data, still I thought it was good to test it a couple of times).
I am pushing everything on the GitHub used with Andreas, for anyone who might be interested.
I still do not know if the code is optimized though. Should you have a better solution, I will happily read it.

As others pointed out your concept of interfaces is wrong still. However i get what you're trying to do.
Try this:
namespace LinkApplication
{
public interface IEventReceiver
{
void Receive<T>(T arg) where T : EventArgs;
}
public class SomeUniqueEvent : EventArgs
{
public bool Clicked { get; set; }
public SomeUniqueEvent(bool clicked)
{
Clicked = clicked;
}
}
public static class EventTunnel
{
private static readonly List<IEventReceiver> _receivers = new List<IEventReceiver>();
public static void Publish<T>(T arg) where T : EventArgs
{
foreach (var receiver in _receivers)
{
receiver.Receive(arg);
}
}
public static void Subscribe(IEventReceiver subscriber)
{
_receivers.Add(subscriber);
}
}
}
namespace ProjectClick
{
public partial class MainWindow : Window
{
public MainWindow()
{
try { InitializeComponent(); }
catch (Exception e)
{
Console.WriteLine(e.InnerException);
}
}
private void Button_Click(object sender, RoutedEventArgs e)
{
LinkApplication.EventTunnel.Publish(new LinkApplication.SomeUniqueEvent(true));
}
private void Button_Leave(object sender, RoutedEventArgs e)
{
LinkApplication.EventTunnel.Publish(new LinkApplication.SomeUniqueEvent(false));
}
}
}
namespace ProjectUser
{
public partial class MainWindow : Window, LinkApplication.IEventReceiver, INotifyPropertyChanged
{
public MainWindow()
{
InitializeComponent();
this.WindowStartupLocation = WindowStartupLocation.CenterScreen; //start the window at the centre of the screen
DataContext = this;
LinkApplication.EventTunnel.Subscribe(this);
}
public bool CompareClick { get; set; }
public bool ClickCheck
{
get { return CompareClick; }
set
{
if (value != CompareClick)
{
CompareClick = value;
OnPropertyChanged("ClickCheck");
}
}
}
public void Receive<T>(T arg) where T : EventArgs
{
var casted = arg as SomeUniqueEvent;
if (casted != null)
{
ClickCheck = casted.Clicked;
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
}

Here, you misunderstand what an interface is. Every implementation of an interface is a different one. When you click the button, CompareClick property of ProjectClick project's MainWindow changes value. But that doesn't change the ProjectUser project's MainWindow. They are two completely different objects! The best way that I can think of now, is to make the button public. Alternatively, you can create a method in the MainWindow class of the ProjectClick. Use this method to subscribe to the click event. Something like this:
public void SubscribeToClickEvent (EventHandler handler) {
this.Button.Click += handler //whatever your button is called
}
If you want to encapsulate Button, use the method above. If you don't, then just make it public.
And you ask, how can I access an instance of MainWindow to use the method? The only way I can think of is to make MainWindow a singleton.

Make a radio button input from a form public in C#?

I've got code and i know I'm 99% of the way there. C# coding in MS VS2008.
Basically I have a form that has 4 radio buttons and a Continue button. the user clicks one of the radio buttons and clicks continue, and this all works fine.
However, I want to use the value entered by the user (i.e. if they click the first button, I want a variable equal to 1, 2nd button equals 2 and so on). I tried doing this in various points but the only place I can get it to run is in the private void btnOkClick line, which means I can use the values outside this void, which is what I really want.
I've tried playing around with setting some enums and such (commented out in the code below), but I can't quite get it. I know I must be close but my novice-ness is truly showing as I keep reading posts and can't quite grasp it.
In short, I want to be able to have other classes in my VS2008 project be able to reference whatever value the user selected in the initial form.
namespace AmortClient
{
public partial class frmLoadACTFCST : Form
{
public frmLoadACTFCST()
{
InitializeComponent();
//set the parent of the form to the container
//this.MdiParent = parent;
}
//public enum ACTFCST
//{
// ACT = 1,
// FCST = 2,
// PLAN = 3,
// FiveYearPlan2012=4
//}
//private ACTFCST _actfcst = ACTFCST.ACT;
//public ACTFCST actfcst
//{
// get { return _actfcst; }
// set { _actfcst = value; }
//}
private void frmLoadACTFCST_Load(object sender, EventArgs e)
{
}
private void groupBox1_Enter(object sender, EventArgs e)
{
}
private void btnActual_CheckedChanged(object sender, EventArgs e)
{
}
private void btnForecast_CheckedChanged(object sender, EventArgs e)
{
}
private void btnPlan_CheckedChanged(object sender, EventArgs e)
{
}
private void btn5YrPlan2012_CheckedChanged(object sender, EventArgs e)
{
}
private void btnContinue_Click(object sender, EventArgs e)
{
string ACTFCSTtext = "";
int dataTypeKey = 0;
if (btnActual.Checked)
{
ACTFCSTtext = btnActual.Text;
dataTypeKey = 1;
}
else if (btnForecast.Checked)
{
ACTFCSTtext = btnForecast.Text;
dataTypeKey = 2;
}
else if (btnPlan.Checked)
{
ACTFCSTtext = btnPlan.Text;
dataTypeKey = 3;
}
else if (btn5YrPlan2012.Checked)
{
ACTFCSTtext = btn5YrPlan2012.Text;
dataTypeKey = 4;
}
string msg = "";
msg = ACTFCSTtext + " " + dataTypeKey;
//btn5YrPlan2012
MessageBox.Show(msg);
Close();
}
}
}

Your dataTypeKey and ACTFCSTtext variables need to be declared as instance variables for your Form object if you want to access them from any other methods within your form. If you want to use them with some other form, you can pass them either as constructor arguments, or set some properties of said other form.
So you'd declare them just after the class declaration if you want them to be instance variables. They should still be private, meaning they can only be accessed from within your frmLoadACTFCST class.
public partial class frmLoadACTFCST : Form
{
private string ACTFCSTtext = "";
private int dataTypeKey = 0;
...
EDIT: if you want to access variables from one object in a different object (or static class), your options are as follows...
1) Declare your variables as public instance variables (same as shown above but public; these are known as Properties when you give them getter and setter methods). Your class that needs access to these variables would need to have a reference to the class that owns the variables.
Example:
FormA has a public property named SomeString.
FormB needs to access SomeString.
FormB needs a reference to FormA, and would access the variable as...
formAReference.SomeString
2) Pass the values of the variables as arguments to some method for the class that needs access.
Example:
FormA has a private instance variable named SomeString.
FormB needs access to SomeString.
If FormA instantiates FormB, it can pass the value of SomeString to FormB's constructor...
//From within FormA's code
FormB formB = new FormB(SomeString);
//FormB's constructor
public FormB(string someString)
{
this.someString = someString;
}

Maybe there is a smarter way to do it.
public partial class frmLoadACTFCST : Form
{
public frmLoadACTFCST()
{
InitializeComponent();
actfcst = ACTFCST.ACT;
btnActual.Tag = ACTFCST.ACT;
btnActual.Checked = true;
btnForecast.Tag = ACTFCST.FCST;
btnPlan.Tag = ACTFSCT.PLAN;
btn5YrPlan2012.Tag = ACTFCST.FiveYearPlan2012;
}
public enum ACTFCST
{
ACT = 1,
FCST = 2,
PLAN = 3,
FiveYearPlan2012=4
}
public static ACTFCST actfcst { get; private set; }
private void CheckedChanged(object sender, EventArgs e)
{
// All the buttons uses this Click-event.
actfcst = (sender as Button).Tag as ACTFCST;
}
private void btnContinue_Click(object sender, EventArgs e)
{
MessageBox.Show(actfcst.ToString());
Close();
}
}
The point is that all the buttons calls CheckedChanged when clicked.
Using a static means that others can access the value using something like this:
frmLoadACTFCST.ACTFCST value = frmLoadACTFCST.actfcst;
// Do something based on value.
I hope this helps you in yoyr quest.

If you select a control in design view, the properties window contains an item named "Modifiers". You can make the control public here.
A better way would be to create a new public property on your form that yields the value of the currently selected radio button.

How can I take items from a listbox and display them in a listview in another form?

I have a listbox full of items for my order.
I want to take all of the items inside my listbox and transfer them into my listview.
Then I want to take my listview and display it in another form (my messagebox).
My new listview:
private void CustomerInfo_Click(object sender, EventArgs e)
{
ListViewItem customers = new ListViewItem(fullName.Text);
customers.SubItems.Add(totalcount.ToString());
customers.SubItems.Add(total.ToString());
customers.SubItems.Add(Address.Text);
customers.SubItems.Add(telephone.Text);
for (int i = 0; i < OrderlistBox.Items.Count; i++)
{
customers.SubItems.Add(OrderlistBox.Items[i].ToString());
}
Customers.Items.Add(customers);
//CLEAR ALL FIELDS
OrderlistBox.Items.Clear();
fullName.Text = "";
Address.Text = "";
telephone.Text = "";
totalDue.Text = "";
totalItems.Text = "";
}
My contextMenuStrip, so when I click on the customer I can get its info (name, address, order, etc.):
private void customerInformationToolStripMenuItem_Click(object sender, EventArgs e)
{
if (Customers.SelectedItems.Count != 0)
{
var myformmessagedialog = new MessageBoxForm
{
name = Customers.SelectedItems[0].SubItems[0].Text,
address = Customers.SelectedItems[0].SubItems[3].Text,
telephone = Customers.SelectedItems[0].SubItems[4].Text,
};
myformmessagedialog.ShowDialog();
}
}
My new form, the messagebox where I will display all the info for the client:
public partial class MessageBoxForm : Form
{
public MessageBoxForm()
{
InitializeComponent();
}
public string name;
public string address;
public string telephone;
public ListViewItem order = new ListViewItem();
private void MessageBoxForm_Load(object sender, EventArgs e)
{
lblName.Text = name;
lbladdress.Text = address;
lbltelephone.Text = telephone;
orderListView.Items.Add(order);
}
}
I'm sorry if this seems confusing but I'm just looking for help to go in the right direction. Any help is appreciated.

One way to do this is to put the data that you want to display in some sort of ViewModel, basically a class or set of classes that has the data that you want to display. Then the main form can display it, and you can pass a reference to that ViewModel to the message box and it can display it as well.
In general you want to avoid any kind of code that directly ties controls from different forms together.

The easiest way based on your current setup is to simply pass your list view data across to your MessageBoxForm e.g.
public partial class MessageBoxForm : Form
{
...
public void LoadListView(ListViewItemCollection items)
{
orderListView.Clear();
orderListView.AddRange(items);
}
}
....
private void customerInformationToolStripMenuItem_Click(object sender, EventArgs e)
{
if (Customers.SelectedItems.Count != 0)
{
var myformmessagedialog = new MessageBoxForm
{
name = Customers.SelectedItems[0].SubItems[0].Text,
address = Customers.SelectedItems[0].SubItems[3].Text,
telephone = Customers.SelectedItems[0].SubItems[4].Text,
};
myformmessagedialog.LoadListView(Customers.Items);
myformmessagedialog.ShowDialog();
}
}

Basic answer is you don't.
You maintain a collection of items (whatever they are).
You display them in a list box.
You display them in a list view.
If you want say select some from the list box and only move them to the list view.
Then you use the listbox selection to find them in your collections of items, create a list of selected ones then passs that to the form with the listview to display.
Don't use UI controls to store your data and try really hard to never make one form's UI directly dependant on another.

I'm guessing what you'd need (and I could have misunderstood what you are looking for) is a new method in you MessageBoxForm to pass in your Customers object:
private void customerInformationToolStripMenuItem_Click(object sender, EventArgs e)
{
if (Customers.SelectedItems.Count != 0)
{
var myformmessagedialog = new MessageBoxForm;
myformmessagedialog.Customers = Customers;
if (myformmessagedialog.ShowDialog() == DialogResult.OK)
{
Customers = myformmessagedialog.Customers;
}
}
}
If so, simply modify your class to be something like this:
public partial class MessageBoxForm : Form
{
public MessageBoxForm()
{
InitializeComponent();
}
private void MessageBoxForm_Load(object sender, EventArgs e)
{
if (Customers != null)
{
// add your code here to add your Customers as needed
}
}
public Customers Customers { get; set; }
}

To access anything from the parent form you need to pass it to the child form so
myformmessagedialog.ShowDialog();
becomes
myformmessagedialog dialog = new myformmessagedialg(this);
dialog.ShowDialog();
and your class constructor becomes this:
public MessageBoxForm(myformmessagedialog parent){
name=parent.fullName.Text;
address=parent.address.Text;
...etc...
InitializeComponent();
}
Though it might be better to just pass in the name, address, etc rather than the whole form, this way is nice for while you are changing things because you have one less place to change to add another variable to pass.

Communication between Multiple Threads in a WPF Application

I added an event handler to my code and it broke all access to the CollectionViewSources in the SystemHTA class saying "The calling thread cannot access this object because a different thread owns it". My class was working when "this.systemHTA = new SystemHTA();" was placed outside of the DeviceManager_StateChanged() function.
public partial class MainWindow : Window
{
private DeviceManager DeviceManager = DeviceManager.Instance;
public SystemHTA systemHTA;
public MainWindow()
{
InitializeComponent();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
DeviceManager.StateChanged += new EventHandler<DeviceManagerStateChangedEventArgs>(DeviceManager_StateChanged);
DeviceManager.Initialize();
}
void DeviceManager_StateChanged(object sender, DeviceManagerStateChangedEventArgs e)
{
if (e.State == DeviceManagerState.Operational)
{
this.systemHTA = new SystemHTA();
}
}
private void button1_Click(object sender, RoutedEventArgs e)
{
this.systemHTA.GetViewSourceTest();
}
}
public class SystemHTA
{
private CollectionViewSource _deviceTestSource;
public SystemHTA()
{
_deviceTestSource = new CollectionViewSource();
_deviceTestSource.Source = CreateLoadData<HWController>.ControllerCollection;
}
public void GetViewSourceTest()
{
ListCollectionView view = (ListCollectionView)_deviceTestSource.View; //This creates an error saying a thread already owns _deviceTestSource
}
}

Ok, CollectionViewSource derived classes, BindableList, ObservableCollection etc these classes can only be created in main dispatcher thread only.
However you have to try something of following sort,
Create your collectionviewsource only in your WPF derived classes, use List<> classes to load your objects in different thread and once done, you can transfer from list to collectionviewsource as follow, I would recommend BindingList because you can add multiple items disabling the refresh to remove flickering.
Create your collection object implicitly in your WPF classes as follow
public class MyWindow : UserControl{
BindingList<MyObject> ObjectList = new BindingList<MyObject>;
public MyWindow(){
ObjectList.AllowAdd = true;
ObjectList.AllowDelete = true;
ObjectList.AllowEdit = true;
}
public void LoadObjects(){
ThreadPool.QueryUserItem( (s)=>{
// load your objects in list first in different thread
List<MyObject> list = MyLongMethodToLoadObjects();
Dispatcher.BeginInvoke( (Action)delegate(){
list.RaiseEvents = false;
foreach(MyObject obj in list){
ObjectList.Add(obj);
}
list.RaiseEvents = true;
list.ResetBindings();
});
});
}
}
I dont know this code does not format correctly but you may try seeing it in visual studio to get correct idea.