Develop Reference

How can I assign same actions to multiple buttons at once?

I am working on a WinForms application where I want the user to click a button and then change the button's text (add +1 to the counter). I have multiple buttons and having three methods Click MouseDown and MouseUp for each of those would be pretty inefficient.
So I've set up a class, but don't know how to assign it to all the buttons.
public class AddButton : Button
{
public int Count { get; set; }
private void Button_Click(object sender, EventArgs e)
{
AddButton ab = (AddButton)sender;
Count++;
ab.Text = Count + " Added";
}
}
Maybe I could also just link all the button's EventHandlers to one, but I don't know how to start there and where to put the code. Here is the Visual Studio project download link if you need it.

You could try this code:
public class AddButton:Button
{
public int Count { get; set; } = 0;
public AddButton()
{
// After it's painted, set its text to current Counter
this.Paint += (s, e) => this.Text = Count.ToString();
this.Click += (s, e) => this.Text = (++Count).ToString();
}
}
In your project it's enough to change buttons initialization from:
Button button1 = new Button();
to
Button button1 = new AddButton();
// or
AddButton button1 = new AddButton();

C# how to make function for all buttons using object sender

I´m using WindowsForm and working with flat design. In the program there are 6 buttons, these buttons are made of a label and a panel. The label controls all the actions that the button can do. when i started writing the program i made one function for each button, now i like to use one function that controls all buttons. I have tried to make that work but I´m stuck and can´t find a way to solve it.
Been looking around at the forum for solutions but i think that i might not know what i´m looking for.
This is what i made so far.
Buttons[] cobra = new Buttons[5];
private class Buttons
{
private bool position;
private string name;
public bool Position
{
get { return position; }
set { position = value; }
}
public string Name
{
get { return name; }
set { name = value; }
}
}
private void SetButtons()
{
cobra[0].Name = "label3";
cobra[0].Position = false;
cobra[1].Name = "label4";
cobra[1].Position = false;
}
private void CheckStatusButtons(object import)
{
for (int i = 0; i < cobra.Length; i++)
{
}
}
private class ToggelFunction
{
private bool hawk;
public bool Hawk
{
get { return hawk; }
set { hawk = value; }
}
}
ToggelFunction tiger = new ToggelFunction();
private void label3_Click(object sender, EventArgs e)
{
if (tiger.Hawk == false)
{
button1.BackColor = Color.PaleGreen;
label3.Text = "ON";
if (myport.IsOpen)
{
send(new byte[] { 16, 128, 32, 16, 1 });
}
tiger.Hawk = true;
return;
}
if (tiger.Hawk == true)
{
button1.BackColor = Color.DarkSeaGreen;
label3.Text = "2";
if (myport.IsOpen)
{
send(new byte[] { 16, 128, 32, 8, 1 });
}
tiger.Hawk = false;
return;
}
}
"label3_Click" this is my function for button 1, all buttons look the same just different variables.
As I found on the forum, you can use object sender to i identify which button that made the click and from there use that in the function to make action.
So all buttons will use this functions, i´m not sure how to compare values in the if statement, if button 1 is click then it should check what values button 1 has.
My idea was to make a class "Buttons" and an array to store all the values of each button, it´s not completed yet. When a button is clicked it checks
with the array what values that button has and compare that in the function depending on what the action is. The first action would be to check if the button is on or off. If it´s off then it enters that if statement and there some actions will happen, change of color and the text, these values also have to be stored in the array i guess.
I have tried to compare the array with object sender, but i get some error saying that you can´t compare bool with object i think.
So i wonder if some one might have a solution or suggestions?

I have made a simple example of what i think you want to do. bare in mind this does not abide by all coding best practises but its not a mess either. You will need to put your safety null checks in.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public class ButtonVariables
{
public int value1 { get; set; }
public int value2 { get; set; }
}
Dictionary<string, ButtonVariables> bv = new Dictionary<string, ButtonVariables>();
private void ProcessClick(object sender, EventArgs e)
{
ButtonVariables vars = GetVariables(sender);
//Do stuff with your variable set here
}
private ButtonVariables GetVariables(object sender)
{
ButtonVariables returnValue = new ButtonVariables();
switch (((Button)sender).Name.ToLower())
{
case "buttona":
return bv["A"];
case "buttonb":
return bv["B"];
case "buttonc":
return bv["C"];
default:
break;
}
return null;
}
private void ButtonA_Click(object sender, EventArgs e)
{
ProcessClick(sender, e);
}
private void ButtonB_Click(object sender, EventArgs e)
{
ProcessClick(sender, e);
}
private void ButtonC_Click(object sender, EventArgs e)
{
ProcessClick(sender, e);
}
}
I've basically added two methods to handle your method. One to identify the button and get its related values from a dictionary that you will have to populate with your Buttons class. and one to carry out the logic.
EDIT
As requested in the comments here's an easy (but not the only way) to point your event listeners towards the same method.
Initially you need to set up with one button and double click it or do some other way to create the forms Button_Click() Event Method. At this point an event listener delegate has been added to your Form.Designer.cs File. Open that file and you will see something like this:
//
// ButtonA
//
this.ButtonA.Location = new System.Drawing.Point(12, 12);
this.ButtonA.Name = "ButtonA";
this.ButtonA.Size = new System.Drawing.Size(75, 23);
this.ButtonA.TabIndex = 0;
this.ButtonA.Text = "button1";
this.ButtonA.UseVisualStyleBackColor = true;
this.ButtonA.Click += new System.EventHandler(this.ButtonA_Click);
What you need to do is create your other buttons and add this code in for them with a change to the last line new System.EventHandler(this.ButtonA_Click); This line basically states which method to call when the ButtonA.Click event is invoked. At this point you can add what ever method you want (as long as you name is nicely for good convention). So your example would be this :
//
// ButtonA
//
this.ButtonA.Location = new System.Drawing.Point(12, 12);
this.ButtonA.Name = "ButtonA";
this.ButtonA.Size = new System.Drawing.Size(75, 23);
this.ButtonA.TabIndex = 0;
this.ButtonA.Text = "button1";
this.ButtonA.UseVisualStyleBackColor = true;
this.ButtonA.Click += new System.EventHandler(this.ProcessClick);
//
// ButtonB
//
this.ButtonB.Location = new System.Drawing.Point(12, 12);
this.ButtonB.Name = "ButtonB";
this.ButtonB.Size = new System.Drawing.Size(75, 23);
this.ButtonB.TabIndex = 0;
this.ButtonB.Text = "B";
this.ButtonB.UseVisualStyleBackColor = true;
this.ButtonB.Click += new System.EventHandler(this.ProcessClick);
//
// ButtonC
//
this.ButtonC.Location = new System.Drawing.Point(12, 12);
this.ButtonC.Name = "ButtonC";
this.ButtonC.Size = new System.Drawing.Size(75, 23);
this.ButtonC.TabIndex = 0;
this.ButtonC.Text = "C";
this.ButtonC.UseVisualStyleBackColor = true;
this.ButtonC.Click += new System.EventHandler(this.ProcessClick);
Remember you need to physically create the buttons on the form itself.

Lets say you have three labels and a panel for each label. You can add the event handler to all of them and whenever that event fires the event handler will use that label as the sender. To keep the panel associated with the label, you could add the panel to the label's tag property. Then, in the event handler you can then get the panel from the label.
label1.Click += label_Click;
label2.Click += label_Click;
label3.Click += label_Click;
label1.Tag = panel1;
label2.Tag = panel2;
label3.Tag = panel3;
In the event handler, just cast sender to Label and there you have your label object to do whatever you want with and like I said, the panel is in the Tag property. I did a little refactoring to your code to make it cleaner looking.
private void label_Click(object sender, EventArgs e)
{
// this is what itsme86 was suggesting in the comments
var label = (Label)sender;
var panel = (Panel)label.Tag;
label.BackColor = tiger.Hawk ? Color.DarkSeaGreen : Color.PaleGreen;
label.Text = tiger.Hawk ? "2" : "ON";
if (myport.IsOpen)
send(new byte[] { 16, 128, 32, 8, 1 });
tiger.Hawk = !tiger.Hawk;
}
Let me know if you have any questions about this.

calling a method from a string name

I'm using c#, and I have a project that instantiates a lot of PictureBox buttons. I also have all of the click,hover,mouseUp,mouseDown event methods programmed. How do I call a method from a string name so that I don't have to write all of them by hand? Thanks in advance, Carson
Dictionary<string, PictureBox> buttonList = new Dictionary<string,PictureBox>();
string buttonName = "button_file";
buttonList[buttonName].Click += new EventHandler(buttonName + "_click");
public void button_file_click(object sender, EventArgs e)
{
// do on click stuff here
}

if you set the Name property of button, you can so:
buttonList[buttonName].Name = buttonName;
buttonList[buttonName].Click += ButtonClick;
and only One metode hanle all buttons click but in accordance of their name:
public void ButtonClick(object sender, EventArgs e)
{
var btn = (Button)sender;
btn.Text = btn.Name; //only for demo
}
but you can completely write your own method:
buttonList[buttonName].Click += (s,e)=> clickEvent(buttonList[buttonName], buttonName);
this is a short lambda function which accepts the parameters accordingly of Click event singature and fire your custom function, the clickEvent:
public void clickEvent(Button thePressedButton, string nameOfPresedButton)
{
thePressedButton.Text = btn.nameOfPresedButton; //only for demo
}

From your sample code, I assume you want them all to call button_file_click.
In that case just set the eventhandler to that method:
buttonList[buttonName].Click += new EventHandler("button_file_click");

A method name isn't quite enough... you also need a class name... but assuming the method belongs to the current class (this) you can use Reflection to do this:
public void ExecuteMethod(string methodName)
{
var methodInfo = this.GetType().GetMethod(methodName);
methodInfo.Invoke(this, new [] {});
}
But you can't assign the above to an event because it is not the right delegate type; most event handlers require a sender and an EventArgs. So to make your code work you'd need a little more glue:
Dictionary<string, PictureBox> buttonList = new Dictionary<string,PictureBox>();
string buttonName = "button_file";
buttonList[buttonName].Click += GetHandler(buttonName + "_click");
public Action<object, EventArgs> GetHandler(string handlerName)
{
var methodInfo = this.GetType().GetMethod(handlerName, new Type[] {typeof(object), typeof(EventArgs)});
return new Action<object, EventArgs> (sender, eventArgs) => methodInfo.Invoke(this, new [] {sender, eventArgs});
}
The idea here is that GetHandler returns an Action with the right signature (accepting an object and an EventArgs, in that order), which is written as Action<object, EventArgs>. The GetHandler method uses reflection to find the right method in the current class, then creates a lambda expression that invokes the method via reflection, passing the arguments as an array.
The above is of course just an example... it would probably be better to store your delegates in a static dictionary that is computed when the page is loaded for the first time.
That being said, if you're looking for event handling flexibility based on a runtime parameter, a better approach is probably to use the Command event, which allows you to pass a string to the handler, which can then take a different action depending on the contents of the string. That way you can hardcode the handler reference but still softcode what it will do.
Dictionary<string, PictureBox> buttonList = new Dictionary<string,PictureBox>();
string buttonName = "button_file";
buttonList[buttonName].Command += buttonList_Command;
buttonList[buttonName].CommandName = buttonName;
protected void buttonList_Command(object sender, CommandEventArgs e)
{
switch (e.CommandName)
{
case buttonName:
//Do stuff for button_file
break;
case "Foo":
//Do stuff for some other button named foo
break;
default:
throw new InvalidOperationException();
}
}

You can use reflection to look up the method of a class by name and then create an event handler delegate using that method. For example:
void bindHandler(string buttonName)
{
string methodName = buttonName + "_click";
System.Reflection.MethodInfo m = this.GetType().GetMethods().FirstOrDefault(x => x.Name == buttonName + "_click");
PictureBox button = buttonList[buttonName];
Delegate handler = Delegate.CreateDelegate(typeof(EventHandler), this, m);
button.Click += (EventHandler)handler;
}
Fulling working code:
namespace WindowsFormsApp1Cs
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
MyClass c = new MyClass();
foreach (var item in c.buttonList)
{
this.Controls.Add(item.Value);
}
}
}
public class MyClass
{
public Dictionary<string, PictureBox> buttonList;
public delegate void MyClickHandler(object sender, EventArgs e);
public MyClass()
{
buttonList = new Dictionary<string, PictureBox>();
buttonList.Add("button_file_1", new PictureBox() { Width = 100, Height = 100, Name = "button_file_1", Anchor = AnchorStyles.Top | AnchorStyles.Left, Top = (buttonList.Count * 100) + 10, Left = 10, ImageLocation="0.jpg" });
buttonList.Add("button_file_2", new PictureBox() { Width = 100, Height = 100, Name = "button_file_2", Anchor = AnchorStyles.Top | AnchorStyles.Left, Top = (buttonList.Count * 100) + 10, Left = 10, ImageLocation = "0.jpg" });
buttonList.Add("button_file_3", new PictureBox() { Width = 100, Height = 100, Name = "button_file_3", Anchor = AnchorStyles.Top | AnchorStyles.Left, Top = (buttonList.Count * 100) + 10, Left = 10, ImageLocation = "0.jpg" });
foreach (var item in buttonList)
{
bindHandler(item.Key);
}
}
void bindHandler(string buttonName)
{
string methodName = buttonName + "_click";
System.Reflection.MethodInfo m = this.GetType().GetMethods().FirstOrDefault(x => x.Name == buttonName + "_click");
PictureBox button = buttonList[buttonName];
Delegate handler = Delegate.CreateDelegate(typeof(EventHandler), this, m);
button.Click += (EventHandler)handler;
}
public void button_file_1_click(object sender, EventArgs e)
{
Debug.WriteLine("button_file_1_click");
}
public void button_file_2_click(object sender, EventArgs e)
{
Debug.WriteLine("button_file_2_click");
}
public void button_file_3_click(object sender, EventArgs e)
{
Debug.WriteLine("button_file_3_click");
}
}
}

Adding events to code-created objects

I am creating a 2d array of buttons using code and I want to add a button_click() method.
Besides the 2 usual arguments (object sender, EventArgs e) I want to get as an input 2 more variables, To identify which button was clicked, and do something else as a result.
I am currently doing this
arr[i,j].Click+= new EventHandler(button_click);
public void button_click(object sender, EventArgs e)
Is there another way of adding events that will allow me to do what I want?
And on a seperate note. Is there an easy way of creating cubes with a certain color without using buttons?

To identify which button was clicked, and do something else as a result.
You could use sender parameter to identify the button which was clicked.
If you do not want to introduce a custom button type which would have properties for i and j, you could use Tag property to store the indices.

Create a class which inherits from button class. And add 2 properties to it. Then access those properties in your form . Following example is one way to solve your problem.
public class ButtonCtrl : Button
{
public ButtonCtrl(int _arg1, int _arg2)
{
Arg1 = _arg1;
Arg2 = _arg2;
}
public int Arg1 { get; set; }
public int Arg2 { get; set; }
}
//create buttons in form c'tor
public Form1()
{
InitializeComponent();
ButtonCtrl button1 = new ButtonCtrl(1,2);
button1.Text = "dynamic 1";
button1.Click += new EventHandler(button_click);
button1.Top = 10;
this.Controls.Add(button1);
ButtonCtrl button2 = new ButtonCtrl(3, 4);
button2.Text = "dynamic 2";
button2.Click += new EventHandler(button_click);
button2.Top = 30;
this.Controls.Add(button2);
}
And the event handler
public void button_click(object sender,EventArgs e)
{
if(sender is ButtonCtrl)
{
ButtonCtrl btnCtrl= sender as ButtonCtrl;
label1.Text = btnCtrl.Arg1.ToString() + " " + btnCtrl.Arg2.ToString();
}
}

Access dynamic control from class in a thread

I'm working on a small project which deals with polling devices to check states of I/O controls. I had implemented a small project dealing with a particular device, but have decided that i would like to eventually implement different devices, and so have moved over to an class : interface approach. This has caused a few problems however, since i moved a lot of code around.
Before i moved the code around and such, i was accessing dynamic form controls by using a delegate as such;
if (result != null)
{
this.Invoke((MethodInvoker)delegate
{
txtOutput1.Text = (result[4] == 0x00 ? "HIGH" : "LOW"); // runs on UI thread
if (result[4] == 0x00)
{
this.Controls["btn" + buttonNumber].BackColor = Color.Green;
}
else
{
this.Controls["btn" + buttonNumber].BackColor = Color.Red;
}
});
}
This worked fine until i moved certain methods to a new class which inherits from an interface. I don't want to just set the dynamic buttons to public, and i'm not sure i can create get;set; for dynamic buttons, considering theres lots of them and are created on startup. Another problem is the this.invoke" command. I believe the invoke command doesn't work unless it's placed on a form...and now it's been moved to a class, so i need to look at another way of doing this.
Does anyone have any ideas as to where i should be heading with this?
EDIT 1:
The program is designed as a monitoring system for hardware devices that handle inputs/outputs. using these i can check if, for example, a door alarm has been triggered and such. The program itself in terms of forms / design is very simple. Currently i have a single form, which generates buttons based on information in a database, for example if there are 10 devices configured, there are 10 buttons. each of these shows green / red dependant on the hardware state.
My main form triggers a thread for each device which monitors it, but because i wished to have multiple types of device i moved them to different classes and an interface which handles all of the common methods. Currently i have a device class, which implements an interface. With regards to this question, i need to now access an instance of the single main form from which i am updating, rather than creating a new instance, so that i can use the new method i created when i moved said logic into the form itself.
EDIT 2:
IdeviceInterface bfdeviceimp = new bf2300deviceimp();
// some other declarations and initialize components
private void btnConnect_Click(object sender, EventArgs e)
{
updateUI();
}
public void updateUI()
{
DBConnector mDBConnector = new DBConnector();
int count = mDBConnector.Count() - 1;
DataTable dataTable = mDBConnector.Select("SELECT * FROM devices");
int x = 12;
int y = 65;
for (int i = 0; i <= count && i < 25; i++)
{
Button btnAdd = new Button();
btnAdd.Text = dataTable.Rows[i]["deviceDescription"].ToString();
btnAdd.Location = new Point(x, y);
btnAdd.Tag = i;
btnAdd.Name = "btn" + i.ToString();
btnAdd.BackColor = Color.Green;
var temp = i + 1;
this.Controls.Add(btnAdd);
this.Controls[btnAdd.Name].MouseClick += (sender, e) =>
{
int index = temp;
generalMethods.generatePopup(sender, e, index);
};
string address = dataTable.Rows[i]["deviceIP"].ToString();
int port = int.Parse(dataTable.Rows[i]["devicePort"].ToString());
ThreadStart workerThread = delegate { start(address, port, i); };
new Thread(workerThread).Start();
x = (x + 75);
if (i != 0 && (i % 5) == 0)
{
x = 12;
y = y + 30;
}
if (i == 25)
{
Button btnPreviousPage = new Button();
btnPreviousPage.Text = "<";
btnPreviousPage.Location = new Point(150, 350);
btnPreviousPage.Tag = "left";
this.Controls.Add(btnPreviousPage);
Button btnNextPage = new Button();
btnNextPage.Text = ">";
btnNextPage.Location = new Point(225, 350);
btnNextPage.Tag = "right";
this.Controls.Add(btnNextPage);
}
}
}
public void start(string address, int port, int i)
{
if (timer == null)
{
timer = new System.Timers.Timer(1000);
timer.Elapsed += delegate(object sender, ElapsedEventArgs e) { timerElapsed(sender, e, address, port, i); };
}
timer.Enabled = true;
// MessageBox.Show("Thread " + i + " Started.");
}
public void timerElapsed(object sender, ElapsedEventArgs e, string address, int port, int i)
{
bfdeviceimp.newconnect(address, port, i);
}
and then finally my device class:
class bf2300deviceimp : IdeviceInterface
{
public void newconnect(string address, int port, int buttonNumber)
{
//send data
byte[] bData = new byte[71];
bData[0] = 240;
bData[1] = 240;
bData[2] = 0;
bData[3] = 1;
bData[68] = 240;
bData[69] = 240;
bData[70] = this.newCalculateCheckSum(bData);
try
{
byte[] result = this.newSendCommandResult(address, port, bData, 72);
//form1.setAlarmColour(result, buttonNumber);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
Where would you suggest i put the statechanged handler?

You should to use an events-based approach for solving this problem, as is often the case when it comes to passing information between forms. Each of your devices should have a custom event that they define which is fired when the state of that device changes. The event should probably just be defined in the interface for interacting with that device. The form, when it creates the various device classes should subscribe to the event and in the event handler it should update the button/textbox appropriately.
This might be a fair bit to take in if you're not used to this style of programming. Feel free to ask for more details in the comments and I can elaborate on why I did something the way I did or what it actually does.
public Form1()
{
InitializeComponent();
//not sure if this is on initialization or in a button click event handler or wherever.
IDevice device = new SomeDevice();
device.StatusChanged += GetHandlerForDevice(1);
device.DoStuff();
IDevice device2 = new SomeDevice(); //could be another class that implements IDevice
device.StatusChanged += GetHandlerForDevice(2);
device.DoStuff();
}
/// <summary>
/// The handlers for device status changed only vary based on the button number for each one.
/// This method takes a button number and returns an event handler that uses that button number.
/// </summary>
/// <param name="buttonNumber"></param>
/// <returns></returns>
private EventHandler<StatusChangedEventArgs> GetHandlerForDevice(int buttonNumber)
{
//use currying so that the event handler which doesn't have an appropriate signature
//can be attached to the status changed event.
return (sender, args) => device_StatusChanged(sender, args, buttonNumber);
}
private void device_StatusChanged(object sender, StatusChangedEventArgs args, int buttonNumber)
{
this.Invoke((MethodInvoker)delegate
{
txtOutput1.Text = (args.CurrentStatus == IDevice.Status.Green ? "HIGH" : "LOW"); // runs on UI thread
if (args.CurrentStatus == IDevice.Status.Green)
{
this.Controls["btn" + buttonNumber].BackColor = Color.Green;
}
else
{
this.Controls["btn" + buttonNumber].BackColor = Color.Red;
}
});
}
public interface IDevice
{
event EventHandler<StatusChangedEventArgs> StatusChanged;
Status CurrentStatus { get; }
public enum Status
{
Green,
Red
}
void DoStuff();
// rest of interface ...
}
public class StatusChangedEventArgs : EventArgs
{
public IDevice.Status CurrentStatus { get; set; }
//can add additional info to pass from an IDevice to a form if needed.
}
public class SomeDevice : IDevice
{
public event EventHandler<StatusChangedEventArgs> StatusChanged;
private IDevice.Status _currentStatus;
/// <summary>
/// Gets the current status of the device this object represents.
/// When set (privately) it fires the StatusChanged event.
/// </summary>
public IDevice.Status CurrentStatus
{
get { return _currentStatus; }
private set
{
_currentStatus = value;
if (StatusChanged != null)
{
StatusChangedEventArgs args = new StatusChangedEventArgs();
args.CurrentStatus = value;
StatusChanged(this, args);
}
}
}
public void DoStuff()
{
//... do stuff
CurrentStatus = IDevice.Status.Green; //will fire status changed event
}
}

Move all the logic inside a method in the form and use it externally.

In your form create a property
public SynchronizationContext SyncContext { get; set;}
In form constructor add:
this.SyncContext = WindowsFormsSynchronizationContext.Current;
Make interface:
public Interface IChangeClient
{
void Process(<some_type> result); // place your logic here
}
(or somethng like that) and implement it in your Form to change your buttons and text.
Extend your original interface to use (maybe as a parameter) SynchronizationContext and IBackgroundChangeClient.
And than your code would look like this:
if (result != null)
{
oSyncContext.Post(new System.Threading.SendOrPostCallback(
delegate(object state)
{
IBackgroundChangeClient client = (state as object[])[0] as IBackgroundChangeClient
//i dont konw the type of this
var innerResult= (state as object[])[1];
client.Process(innerResult);
}), new object[] { oBackgroundChangeClient, result[4]});
}