I added this in my code:
namespace uartToCs_version_2._0
{
public partial class formMain : Form
{
==> public static SerialPort serial = new SerialPort();
But I didn't use the design tab, so how should I go about event handling (with the current setup I can use it in other forms too, will that still be possible)?
My design file
public Form1()
{
InitializeComponent();
//add DataReceived event of serial
Form1.serial.DataReceived += serial_DataReceived;
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
//remove DataReceived event of serial
Form1.serial.DataReceived -= serial_DataReceived;
}
void serial_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
//process data here
}
You can register the events either in any method like Load() or in the constructor. I used the constructor below. You can't register event until all the needed properties are setup. I did not show the setup code.
public partial class Form1 : Form
{
public static SerialPort serial = new SerialPort();
public Form1()
{
InitializeComponent();
serial.DataReceived += new SerialDataReceivedEventHandler(serial_DataReceived);
}
private void serial_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
}
}
Related
I've created a new form, in which I have a toolbox. When I press a button in that form, it should relay that information that has been entered by the user(toolboxbox value) to the main form, in which it should say that piece of information in a label.
Since the method to create that username from the toolbox is private, I cannot access it from any other way. Making it public does not seem to make a difference, neither does get,set (from the way I've been trying to atleast).
Picture that may help explaining it:
Code (in which to create user):
namespace WindowsFormsApplication3
{
public partial class Newuserform : Form
{
public Newuserform()
{
InitializeComponent();
}
private void buttonCreateUser_Click(object sender, EventArgs e)
{
string uname = textboxUsername.ToString();
}
public void Unamecreate()
{
}
}
}
Form1 Code (To receive created user):
namespace WindowsFormsApplication3
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void exitToolStripMenuItem_Click(object sender, EventArgs e)
{
Application.Exit();
}
private void aboutToolStripMenuItem1_Click(object sender, EventArgs e)
{
Aboutform form2 = new Aboutform();
form2.Show();
}
private void newLocalUserToolStripMenuItem_Click(object sender, EventArgs e)
{
Newuserform formnewuser = new Newuserform();
formnewuser.Show();
}
}
}
you have a lot of options.
One way is to create an event and handle it in the main form.
public partial class Newuserform : Form
{
//the public property
public event EventHandler<string> UnameChanged;
public Newuserform()
{
InitializeComponent();
}
private void buttonCreateUser_Click(object sender, EventArgs e)
{
if (UnameChanged != null)
UnameChanged(textboxUsername.ToString()); //fire the event
}
}
Now, to "handle" the event, do the following in your main form:
private void newLocalUserToolStripMenuItem_Click(object sender, EventArgs e)
{
Newuserform formnewuser = new Newuserform();
formnewuser.UnameChanged += Handler;
formnewuser.Show();
}
private void Handler (object sender, string Uname)
{
// do something wit the new Uname.
}
note: recreating the Newuserform will require to cleanup previous attached resources.
I am writing an application that passes gps data from a main form to a gps form at a constant interval (using a timer).
I've used the following tutorial to make a quick test:
http://www.codeproject.com/Articles/17371/Passing-Data-between-Windows-Forms
However, when I start the code no event is triggered. First I got a nullpointer. after adding the following lines I got rid of it:
if (GpsUpdated != null)
{
GpsUpdated(this, args);
}
Main form code:
public partial class Form1 : Form
{
// add a delegate
public delegate void GpsUpdateHandler(object sender, GpsUpdateEventArgs e);
// add an event of the delegate type
public event GpsUpdateHandler GpsUpdated;
int lat = 1;
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
Form_GPS form_gps = new Form_GPS();
form_gps.Show();
timer1.Enabled = true;
}
private void timer1_Tick(object sender, EventArgs e)
{
Debug.WriteLine("Timer Tick");
// instance the event args and pass it each value
GpsUpdateEventArgs args = new GpsUpdateEventArgs(lat);
// raise the event with the updated arguments
if (GpsUpdated != null)
{
GpsUpdated(this, args);
}
}
}
public class GpsUpdateEventArgs : EventArgs
{
private int lat;
// class constructor
public GpsUpdateEventArgs(int _lat)
{
this.lat = _lat;
}
// Properties - Viewable by each listener
public int Lat
{
get
{
return lat;
}
}
}
GPS form code:
public partial class Form_GPS : Form
{
public Form_GPS()
{
InitializeComponent();
}
private void Form_GPS_Load(object sender, EventArgs e)
{
Debug.WriteLine("GPS Form loaded");
Form1 f = new Form1();
// Add an event handler to update this form
// when the ID form is updated (when
// GPSUpdated fires).
f.GpsUpdated += new Form1.GpsUpdateHandler(gps_updated);
}
// handles the event from Form1
private void gps_updated(object sender,GpsUpdateEventArgs e)
{
Debug.WriteLine("Event fired");
Debug.WriteLine(e.Lat.ToString());
}
}
Can anyone point me in the right direction? What am I doing wrong?
Thanks in advance and with best regards.
You should pass an instance of Form1 to your Form_GPS for it to work properly. See the following changes:
public partial class Form_GPS : Form
{
public Form_GPS(Form1 owner)
{
InitializeComponent();
owner.GpsUpdated += new Form1.GpsUpdateHandler(gps_updated);
}
private void Form_GPS_Load(object sender, EventArgs e)
{
Debug.WriteLine("GPS Form loaded");
}
// handles the event from Form1
private void gps_updated(object sender,GpsUpdateEventArgs e)
{
Debug.WriteLine("Event fired");
Debug.WriteLine(e.Lat.ToString());
}
}
Now you need to a small change in Form1 as well:
private void Form1_Load(object sender, EventArgs e)
{
Form_GPS form_gps = new Form_GPS(this);
form_gps.Show();
timer1.Enabled = true;
}
Notice how you pass an instance of Form1 to Form_GPS in the constructor of Form_GPS using the self reference this.
Declaring the event as following solved the problem:
public static event GpsUpdateHandler GpsUpdated;
instead of:
public event GpsUpdateHandler GpsUpdated;
In this way the Form1 event can be called static, so no new instance is necessary.
I have a serial port class, and I would like to control send/receive via my GUI, and have the GUI update based on receipt of data from the serial port (or other events). So the two relevant classes are the serial class and the main window class.
I have the code below which compiles, but I get an exception when I try to run.
public class MySerThread
{
public SerialPort serport;
public event SerialDataReceivedEventHandler newSerData;
public MySerThread()
{
serport = new SerialPort("COM1", 115200);
serport.Open();
serport.DataReceived += DataReceivedHandler;
}
public void DataReceivedHandler(object s, SerialDataReceivedEventArgs e)
{
byte[] data = new byte[serport.BytesToRead];
serport.Read(data, 0, data.Length);
// here's where I think I'm going wrong?
if(newSerData != null)
newSerData(s,e);
}
}
And then in my GUI class...
public partial class MainWindow : Window
{
MySerThread myPort;
public MainWindow()
{
// Exception triggers here
myPort.newSerData += DisplaySerDataHandler;
}
private void DisplaySerDataHandler(object sender, SerialDataReceivedEventArgs e)
{
this.ReceivedCallback(e);
}
private void ReceivedCallback(SerialDataReceivedEventArgs e)
{
if(this.someTextBlock.Dispatcher.CheckAccess())
{
this.UpdateTextBlock(e);
}
else
{
this.someTextBlock.Dispatcher.BeginInvoke(new Action<SerialDataReceivedEventArgs>(this.UpdateTextBlock), e);
}
}
private void UpdateTextBlock(SerialDataReceivedEventArgs e)
{
someTextBlock.Text = "got new data";
}
}
So, what am I doing wrong here? What is the best way to do this?
You can't access myPort without creating an instance.
MySerThread myPort = new MySerThread();
Would you look at my code and tell me where I went wrong? in following code I am trying to send a notification to myMethod() method when Form1 gets maximized.
Thanks!
namespace WindowsDelegate1
{
public delegate void ChangedEventHandler(object sender, EventArgs e);
class myForm : Form
{
public event ChangedEventHandler Changed;
protected virtual void OnChanged(EventArgs e)
{
if (Changed != null)
Changed(this,e);
}
public override System.Drawing.Size MaximumSize
{
//get
//{
// return base.MaximumSize;
//}
set
{
base.MaximumSize = value;
OnChanged(EventArgs.Empty);
}
}
}
}
namespace WindowsDelegate1
{
class EventListener
{
private myForm TheForm;
public EventListener(myForm theform)
{
TheForm = theform;
TheForm.Changed += new ChangedEventHandler(myMethod);
}
private void myMethod(object sender, EventArgs e)
{
MessageBox.Show("hey, window should be maximized now!");
}
public void Detach()
{
TheForm.Changed -= new ChangedEventHandler(myMethod);
TheForm = null;
}
}
}
Here is the testing unit / or main()
namespace WindowsDelegate1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
myForm f = new myForm();
EventListener listener = new EventListener(f);
f.ShowDialog();
f.WindowState = FormWindowState.Maximized;
listener.Detach();
}
}
}
What's probably happening is the event is either fired after your .Detach() call, or is never fired at all. I would start by removing the listener.Detach() call. Generally, you attach to events when the form is created or when it loads and detach when it is unloading.
Other than that, your Detach method is problematic because it tries to remove a different ChangedEventHandler instance than the one added. If you're wrapping your methods in ChangedEventHandler you need to store the instance you added.
Thank you for sharing your ideas!
I fixed it by removing the property (not idea why I used that!!) and using method instead by:
protected override void OnActivated(EventArgs e)
{
base.OnActivated(e);
OnChanged(EventArgs.Empty);
}
I have updated my source code above too
I have a problem with my SerialDataReceivedEventHandler whitch fails to respond to data in serail port.
I have one main form in whitch i open port and do other stuf whitch need to be done for proper serial port communication (sending and receiving work)!
Then i open another form in same project whitch need same serial port for reading and writing!
Problem is that my SerialDataReceivedEventHandler in form2 not working jet it is completely identical to the first in mainform. (if i call serial.close() in main form app freezes or cause huge delay)
probably i have to make in my main from this event public, but i still don't konow how to make my custom event or something else that will trigger the event in form 2 that data is arrived on port
I found this link for help but does not work with my app.
http://social.msdn.microsoft.com/Forums/en/netfxbcl/thread/7efccf0e-b412-4869-b942-a006773a833f
i'm using VS2008,framework3.5 (smart device project)
can somebody help me with that? , Please!
Move your SerialPort consumption into a separate static (or a singleton) class. Create a DataReceived event in that class and fire it every time data is received. Have both forms subscribe to the DataReceived event - this way both forms will receive the data.
Edit 1: Sample in pseudo code
public static class Serial {
public static delegate void DataReceivedEventHandler(object sender, ReceivedEventArgs e);
public static event DataReceivedEventHandler DataReceived;
static SerialPort serialPort = new SerialPort();
static Serial() {
serialPort = new SerialPort();
serialPort.DataReceived += Incoming;
serialPort.Open();
}
private static void Incoming(object sender, SerialDataReceivedEventHandler args) {
if (DataReceived != null) {
ReceivedEventArgs rea = new ReceivedEventArgs {Data = args.Data};
DataReceived(this, rea);
}
}
}
public class ReceivedEventArgs : EventArgs {
public string Data { get; set;}
}
public class Form1: Form {
public Form1() {
Serial.DataReceived += Incoming;
}
private void Incoming(object sender, ReceivedEventArgs e) {
// you receive the data here
Debug.WriteLine(e.Data);
}
}
public class Form2: Form {
public Form2() {
Serial.DataReceived += Incoming;
}
private void Incoming(object sender, ReceivedEventArgs e) {
// you receive the data here
Debug.WriteLine(e.Data);
}
}
Again, this is pseudo code, without compiler nearby. Hope this helps.