There's a duplicate post but the question was not answered.
My question is if a new form is created within a main form
var editor = new Edit(itemList, itemListBox);
editor.Show();
and the type of data you edit is:
Dictionary<int, Item>
Item is below:
public class Item
{
public string #Url { get; set; }
public string Name { get; set; }
public double Price { get; set; }
public Item(string #url, string name, double price)
{
this.Url = url;
this.Name = name;
this.Price = price;
}
public override string ToString()
{
return this.Name;
}
}
How can i add a handler for when editor is closed so it can update the ListBox in the main windows form.
Either add an eventhandler for the Form.Closed event
var editor = new Edit(itemList, itemListBox);
editor.Closed += OnEditorClosed(); // your eventhandler here
editor.Show();
or simply create modal dialog by using ShowDialog instead of Show
var editor = new Edit(itemList, itemListBox);
editor.ShowDialog(); // execution will stop here until editor is closed
Form has event handlers FormClosing and FormClosed. I think it'll be better to use the first one, since in the second the form's data may be alrready disposed. So:
editor.FormClosing += new FormClosingEventHandler(editor_FormClosing);
private void editor_FormClosing(object sender, FormClosingEventArgs e)
{
Edit editor = (Edit)sender;
// update data on main form here
}
Related
In my C# windows form I have 2 forms. I would like to display a collection of strings in a label on a form. When I debug I show the 2 elements in my array but they are not showing in the label I am passing it to. When I hover of toString the data is there but how to I pass it to sender so it will display in the label control I have on my form?
In the snippet of code below to data is in toString but how do I get it from there down to sender.ToString????
public AccountReport_cs(Func<string> toString)
{
this.toString = toString;
}
private void AccountReport_cs_Load(object sender, EventArgs e)
{
label1.Text = sender.ToString();
}
This is another piece of the code that will open form2 where the information should be displayed.
private void reportButton2_Start(object sender, EventArgs e)
{
AccountReport_cs accountReport = new AccountReport_cs(allTransactions.ToString);
accountReport.ShowDialog();
}
Here is the last piece of code and this will show how the data gets to EndOfMonth.
public class Transaction
{
public string EndOfMonth { get; set; }
}
public override List<Transaction> closeMonth()
{
var transactions = new List<Transaction>();
var endString = new Transaction();
endString.EndOfMonth = reportString;
transactions.Add(endString);
return transactions;
}
If you need to send information between forms, the best thing you can do is create a property in the target form and assign the value you want to send before displaying the form; thus you will not need to change the default constructor of the form.
// Destiny form
public partial class FormDestiny : Form {
// Property for receive data from other forms, you decide the datatype
public string ExternalData { get; set; }
public FormDestiny() {
InitializeComponent();
// Set external data after InitializeComponent()
this.MyLabel.Text = ExternalData;
}
}
// Source form. Here, prepare all data to send to destiny form
public partial class FormSource : Form {
public FormSource() {
InitializeComponent();
}
private void SenderButton_Click(object sender, EventArgs e) {
// Instance of destiny form
FormDestiny destinyForm = new FormDestiny();
destinyForm.ExternalData = PrepareExternalData("someValueIfNeeded");
destinyForm.ShowDialog();
}
// Your business logic here
private string PrepareExternalData(string myparameters) {
string result = "";
// Some beautiful and complex code...
return result;
}
}
I am working in Visual Studio running a Windows application.
I am wondering if I can fill a DataGridView from a TextBox, that was a passed value itself?
For example, the user would search for a patient from a dialog form. The patient's name they select would populate a TextBox on my main form. I want that selected patients prior test history to populate a DataGridView on that main form within a tab.
Is this possible, if so how would I accomplish this?
It is possible. I would suggest setting up some sort of data binding. More specifically you will want some class that maintains state and data binds to your controls and possibly your dialog form. I don't know how much you are looking for so this might be going overboard but I would suggest something like this:
public class MainForm : Form
{
public MainForm(StateManager stateManager)
{
_stateManager = stateManager;
//data binding for your text box
txtPatientName.DataBindings.Add(nameof(txtPatientName.Text), stateManager, nameof(stateManager.PatientName));
//data binding for your grid
historyGrid.DataSource = stateManager.History;
}
private void btnShowForm_Click(object sender, EventArgs e)
{
using(var form = new DialogForm())
{
var result = form.ShowDialog();
if(result == DialogResult.Ok)
{
_stateManager.UpdatePatient(form.InputPatientName);
}
}
}
private StateManager _stateManager;
}
//this is the form where you enter the patient name
public class DialogForm : Form
{
//this holds the value where the patient's name is entered on the form
public string InputPatientName { get; set; }
}
//this class maintains your state
public class StateManager : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public string PatientName
{
get { return _patientName; }
set
{
_patientName = value;
OnPropertyChanged(nameof(PatientName));
}
}
public BindingList<MedicalHistoryItems> History => _history ?? (_history = new BindingList<MedicalHistoryItems>());
public void UpdatePatient(string patientName)
{
History.Clear();
var historyRetriever = new HistoryRetriever();
History.AddRange(historyRetriever.RetrieveHistory(patientName));
}
private void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(propertyName);
}
private BindingList<MedicalHistoryItems> _history;
private string _patientName;
}
I have a main form (let's call it frmHireQuote) that is a child of a main MDI form (frmMainMDI), that shows another form (frmImportContact) via ShowDialog() when a button is clicked.
When the user clicks the 'OK' on frmImportContact, I want to pass a few string variables back to some text boxes on frmHireQuote.
Note that there could be multiple instances of frmHireQuote, it's obviously important that I get back to the instance that called this instance of frmImportContact.
What's the best method of doing this?
Create some public Properties on your sub-form like so
public string ReturnValue1 {get;set;}
public string ReturnValue2 {get;set;}
then set this inside your sub-form ok button click handler
private void btnOk_Click(object sender,EventArgs e)
{
this.ReturnValue1 = "Something";
this.ReturnValue2 = DateTime.Now.ToString(); //example
this.DialogResult = DialogResult.OK;
this.Close();
}
Then in your frmHireQuote form, when you open the sub-form
using (var form = new frmImportContact())
{
var result = form.ShowDialog();
if (result == DialogResult.OK)
{
string val = form.ReturnValue1; //values preserved after close
string dateString = form.ReturnValue2;
//Do something here with these values
//for example
this.txtSomething.Text = val;
}
}
Additionaly if you wish to cancel out of the sub-form you can just add a button to the form and set its DialogResult to Cancel and you can also set the CancelButton property of the form to said button - this will enable the escape key to cancel out of the form.
I normally create a static method on form/dialog, that I can call. This returns the success (OK-button) or failure, along with the values that needs to be filled in.
public class ResultFromFrmMain {
public DialogResult Result { get; set; }
public string Field1 { get; set; }
}
And on the form:
public static ResultFromFrmMain Execute() {
using (var f = new frmMain()) {
var result = new ResultFromFrmMain();
result.Result = f.ShowDialog();
if (result.Result == DialogResult.OK) {
// fill other values
}
return result;
}
}
To call your form;
public void MyEventToCallForm() {
var result = frmMain.Execute();
if (result.Result == DialogResult.OK) {
myTextBox.Text = result.Field1; // or something like that
}
}
Found another small problem with this code... or at least it was problematic when I tried to implement it.
The buttons in frmMain do not return a compatible value, using VS2010 I added the following and everything started working fine.
public static ResultFromFrmMain Execute() {
using (var f = new frmMain()) {
f.buttonOK.DialogResult = DialogResult.OK;
f.buttonCancel.DialogResult = DialogResult.Cancel;
var result = new ResultFromFrmMain();
result.Result = f.ShowDialog();
if (result.Result == DialogResult.OK) {
// fill other values
}
return result;
}
}
After adding the two button values, the dialog worked great!
Thanks for the example, it really helped.
delegates are the best option for sending data from one form to another.
public partial class frmImportContact : Form
{
public delegate void callback_data(string someData);
public event callback_data getData_CallBack;
private void button_Click(object sender, EventArgs e)
{
string myData = "Top Secret Data To Share";
getData_CallBack(myData);
}
}
public partial class frmHireQuote : Form
{
private void Button_Click(object sender, EventArgs e)
{
frmImportContact obj = new frmImportContact();
obj.getData_CallBack += getData;
}
private void getData(string someData)
{
MessageBox.Show("someData");
}
}
I just put into constructor something by reference, so the subform can change its value and main form can get new or modified object from subform.
If you want to pass data to form2 from form1 without passing like new form(sting "data");
Do like that
in form 1
using (Form2 form2= new Form2())
{
form2.ReturnValue1 = "lalala";
form2.ShowDialog();
}
in form 2 add
public string ReturnValue1 { get; set; }
private void form2_Load(object sender, EventArgs e)
{
MessageBox.Show(ReturnValue1);
}
Also you can use value in form1 like this if you want to swap something in form1
just in form1
textbox.Text =form2.ReturnValue1
I use MDI quite a lot, I like it much more (where it can be used) than multiple floating forms.
But to get the best from it you need to get to grips with your own events. It makes life so much easier for you.
A skeletal example.
Have your own interupt types,
//Clock, Stock and Accoubts represent the actual forms in
//the MDI application. When I have multiple copies of a form
//I also give them an ID, at the time they are created, then
//include that ID in the Args class.
public enum InteruptSource
{
IS_CLOCK = 0, IS_STOCKS, IS_ACCOUNTS
}
//This particular event type is time based,
//but you can add others to it, such as document
//based.
public enum EVInterupts
{
CI_NEWDAY = 0, CI_NEWMONTH, CI_NEWYEAR, CI_PAYDAY, CI_STOCKPAYOUT,
CI_STOCKIN, DO_NEWEMAIL, DO_SAVETOARCHIVE
}
Then your own Args type
public class ControlArgs
{
//MDI form source
public InteruptSource source { get; set; }
//Interrupt type
public EVInterupts clockInt { get; set; }
//in this case only a date is needed
//but normally I include optional data (as if a C UNION type)
//the form that responds to the event decides if
//the data is for it.
public DateTime date { get; set; }
//CI_STOCKIN
public StockClass inStock { get; set; }
}
Then use the delegate within your namespace, but outside of a class
namespace MyApplication
{
public delegate void StoreHandler(object sender, ControlArgs e);
public partial class Form1 : Form
{
//your main form
}
Now either manually or using the GUI, have the MDIparent respond to the events of the child forms.
But with your owr Args, you can reduce this to a single function. and you can have provision to interupt the interupts, good for debugging, but can be usefull in other ways too.
Just have al of your mdiparent event codes point to the one function,
calendar.Friday += new StoreHandler(MyEvents);
calendar.Saturday += new StoreHandler(MyEvents);
calendar.Sunday += new StoreHandler(MyEvents);
calendar.PayDay += new StoreHandler(MyEvents);
calendar.NewYear += new StoreHandler(MyEvents);
A simple switch mechanism is usually enough to pass events on to appropriate forms.
First you have to define attribute in form2(child) you will update this attribute in form2 and also from form1(parent) :
public string Response { get; set; }
private void OkButton_Click(object sender, EventArgs e)
{
Response = "ok";
}
private void CancelButton_Click(object sender, EventArgs e)
{
Response = "Cancel";
}
Calling of form2(child) from form1(parent):
using (Form2 formObject= new Form2() )
{
formObject.ShowDialog();
string result = formObject.Response;
//to update response of form2 after saving in result
formObject.Response="";
// do what ever with result...
MessageBox.Show("Response from form2: "+result);
}
I raise an event in the the form setting the value and subscribe to that event in the form(s) that need to deal with the value change.
I have a main form (let's call it frmHireQuote) that is a child of a main MDI form (frmMainMDI), that shows another form (frmImportContact) via ShowDialog() when a button is clicked.
When the user clicks the 'OK' on frmImportContact, I want to pass a few string variables back to some text boxes on frmHireQuote.
Note that there could be multiple instances of frmHireQuote, it's obviously important that I get back to the instance that called this instance of frmImportContact.
What's the best method of doing this?
Create some public Properties on your sub-form like so
public string ReturnValue1 {get;set;}
public string ReturnValue2 {get;set;}
then set this inside your sub-form ok button click handler
private void btnOk_Click(object sender,EventArgs e)
{
this.ReturnValue1 = "Something";
this.ReturnValue2 = DateTime.Now.ToString(); //example
this.DialogResult = DialogResult.OK;
this.Close();
}
Then in your frmHireQuote form, when you open the sub-form
using (var form = new frmImportContact())
{
var result = form.ShowDialog();
if (result == DialogResult.OK)
{
string val = form.ReturnValue1; //values preserved after close
string dateString = form.ReturnValue2;
//Do something here with these values
//for example
this.txtSomething.Text = val;
}
}
Additionaly if you wish to cancel out of the sub-form you can just add a button to the form and set its DialogResult to Cancel and you can also set the CancelButton property of the form to said button - this will enable the escape key to cancel out of the form.
I normally create a static method on form/dialog, that I can call. This returns the success (OK-button) or failure, along with the values that needs to be filled in.
public class ResultFromFrmMain {
public DialogResult Result { get; set; }
public string Field1 { get; set; }
}
And on the form:
public static ResultFromFrmMain Execute() {
using (var f = new frmMain()) {
var result = new ResultFromFrmMain();
result.Result = f.ShowDialog();
if (result.Result == DialogResult.OK) {
// fill other values
}
return result;
}
}
To call your form;
public void MyEventToCallForm() {
var result = frmMain.Execute();
if (result.Result == DialogResult.OK) {
myTextBox.Text = result.Field1; // or something like that
}
}
Found another small problem with this code... or at least it was problematic when I tried to implement it.
The buttons in frmMain do not return a compatible value, using VS2010 I added the following and everything started working fine.
public static ResultFromFrmMain Execute() {
using (var f = new frmMain()) {
f.buttonOK.DialogResult = DialogResult.OK;
f.buttonCancel.DialogResult = DialogResult.Cancel;
var result = new ResultFromFrmMain();
result.Result = f.ShowDialog();
if (result.Result == DialogResult.OK) {
// fill other values
}
return result;
}
}
After adding the two button values, the dialog worked great!
Thanks for the example, it really helped.
delegates are the best option for sending data from one form to another.
public partial class frmImportContact : Form
{
public delegate void callback_data(string someData);
public event callback_data getData_CallBack;
private void button_Click(object sender, EventArgs e)
{
string myData = "Top Secret Data To Share";
getData_CallBack(myData);
}
}
public partial class frmHireQuote : Form
{
private void Button_Click(object sender, EventArgs e)
{
frmImportContact obj = new frmImportContact();
obj.getData_CallBack += getData;
}
private void getData(string someData)
{
MessageBox.Show("someData");
}
}
I just put into constructor something by reference, so the subform can change its value and main form can get new or modified object from subform.
If you want to pass data to form2 from form1 without passing like new form(sting "data");
Do like that
in form 1
using (Form2 form2= new Form2())
{
form2.ReturnValue1 = "lalala";
form2.ShowDialog();
}
in form 2 add
public string ReturnValue1 { get; set; }
private void form2_Load(object sender, EventArgs e)
{
MessageBox.Show(ReturnValue1);
}
Also you can use value in form1 like this if you want to swap something in form1
just in form1
textbox.Text =form2.ReturnValue1
I use MDI quite a lot, I like it much more (where it can be used) than multiple floating forms.
But to get the best from it you need to get to grips with your own events. It makes life so much easier for you.
A skeletal example.
Have your own interupt types,
//Clock, Stock and Accoubts represent the actual forms in
//the MDI application. When I have multiple copies of a form
//I also give them an ID, at the time they are created, then
//include that ID in the Args class.
public enum InteruptSource
{
IS_CLOCK = 0, IS_STOCKS, IS_ACCOUNTS
}
//This particular event type is time based,
//but you can add others to it, such as document
//based.
public enum EVInterupts
{
CI_NEWDAY = 0, CI_NEWMONTH, CI_NEWYEAR, CI_PAYDAY, CI_STOCKPAYOUT,
CI_STOCKIN, DO_NEWEMAIL, DO_SAVETOARCHIVE
}
Then your own Args type
public class ControlArgs
{
//MDI form source
public InteruptSource source { get; set; }
//Interrupt type
public EVInterupts clockInt { get; set; }
//in this case only a date is needed
//but normally I include optional data (as if a C UNION type)
//the form that responds to the event decides if
//the data is for it.
public DateTime date { get; set; }
//CI_STOCKIN
public StockClass inStock { get; set; }
}
Then use the delegate within your namespace, but outside of a class
namespace MyApplication
{
public delegate void StoreHandler(object sender, ControlArgs e);
public partial class Form1 : Form
{
//your main form
}
Now either manually or using the GUI, have the MDIparent respond to the events of the child forms.
But with your owr Args, you can reduce this to a single function. and you can have provision to interupt the interupts, good for debugging, but can be usefull in other ways too.
Just have al of your mdiparent event codes point to the one function,
calendar.Friday += new StoreHandler(MyEvents);
calendar.Saturday += new StoreHandler(MyEvents);
calendar.Sunday += new StoreHandler(MyEvents);
calendar.PayDay += new StoreHandler(MyEvents);
calendar.NewYear += new StoreHandler(MyEvents);
A simple switch mechanism is usually enough to pass events on to appropriate forms.
First you have to define attribute in form2(child) you will update this attribute in form2 and also from form1(parent) :
public string Response { get; set; }
private void OkButton_Click(object sender, EventArgs e)
{
Response = "ok";
}
private void CancelButton_Click(object sender, EventArgs e)
{
Response = "Cancel";
}
Calling of form2(child) from form1(parent):
using (Form2 formObject= new Form2() )
{
formObject.ShowDialog();
string result = formObject.Response;
//to update response of form2 after saving in result
formObject.Response="";
// do what ever with result...
MessageBox.Show("Response from form2: "+result);
}
I raise an event in the the form setting the value and subscribe to that event in the form(s) that need to deal with the value change.
I have three user controls. Here are the description of them:
1) First user control(ucCountry) contains combobox which displays country names from an xml file.
2) Second user control(ucChannelType) contains two radio buttons one to select TV and other to select Radio Channel Type.
3) Third usercontrol(ucChannels) will populate all the channels where country name is provided by ucCountry and type provided by ucChannelType
Now, how to communicate between these user control in a form. I need to decouple the usercontrols from the form. So, I need to use events. But if ucCountry fires an event (say CountryChanged event) and ucChannels subscribe the event, how to get the channel type from ucChannelType.
Thanks in advance...
best solution is to add properties to your custom controls. there may be no fields in background, the getters will just get data from property of internal standard control.
You could either have a property on ucCountry which provides the currently selected country. Something like:
public Country SelectedCountry
{
get
{
return (Country) myComboBox.SelectedItem;
}
}
And then when the event fires, the other controls go a get the property.
The other option is to use a custom event delegate, so the event handler for ucCountry.CountryChanged would have a country parameter:
public delegate void CountryChangedDelegate(Country sender)
public event CountryChangedDelegate CountryChanged;
Event handler in ucChannels:
public void ucCountry_CountryChanged(Country sender)
{
//do something with the new country
}
And wire the event to ucChannels:
myUcCountry.CountryChanged += new CountryChangedDelegate(ucCountry_CountryChanged);
You need to have public properties for the controls supplying data, and a public method to register events to for the control consuming the data. Here's a quick example:
public static void Test()
{
var a = new A();
var b = new B();
var c = new C() {a = a, b = b};
a.OnChange += c.Changed;
b.OnChange += c.Changed;
a.State = "CA";
b.ChannelType = "TV";
}
class A
{
private string _state;
public string State
{
get { return _state; }
set
{
_state = value;
if (OnChange != null) OnChange(this, EventArgs.Empty);
}
}
public event EventHandler<EventArgs> OnChange;
}
class B
{
private string _channelType;
public string ChannelType
{
get { return _channelType; }
set
{
_channelType = value;
if (OnChange != null) OnChange(this, EventArgs.Empty);
}
}
public event EventHandler<EventArgs> OnChange;
}
class C
{
public A a { get; set; }
public B b { get; set; }
public void Changed(object sender, EventArgs e)
{
Console.WriteLine("State: {0}\tChannelType: {1}", a.State, b.ChannelType);
}
}