I made a combobox with the name FormatComboBox. I populated it with a list of items. I want to trigger an event whenever the user selects an item from the list. The following is my code.
private void FormatComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
/// some code
}
I put a break point inside the code to see whether it is working and found that it isn't. After I tried using
private void FormatComboBox_SelectedValueChanged(object sender, EventArgs e)
private void FormatComboBox_SelectedItemChanged(object sender, EventArgs e)
I am working on c# for the first time and I was following this tutorial
http://www.kinectingforwindows.com/2013/04/09/tutorial-kinect-television/
The one they used was the following
private void OnSelectedFormatChanged(object sender, SelectionChangedEventArgs e)
But even that is not working
Make sure that the event is attached to the FormatComboBox.
By design:
By Code:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
comboBox1.SelectedIndexChanged +=comboBox1_SelectedIndexChanged;
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
}
}
You need to make sure that you are actually adding the event handler properly in your code or in the text box's properties. It should look something like this:
public partial class Form1 : Form
{
FormatComboBox fbox = new FormatComboBox();
// Associate event handler to the combo box.
fbox.SelectedValueChanged+=FormatComboBox_SelectedValueChanged;
prviate void FormatComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
// do stuff
}
}
Related
I have a project that uses various click events and looks like this
namespace Example
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btn_obj_Click(object sender, EventArgs e)
{
MyMethods.Method_1("text1");
}
private void btn_catg_Click(object sender, EventArgs e)
{
MyMethods.Method_1("text2");
}
private void btn_up_Click(object sender, EventArgs e)
{
MyMethods.Method_2("text1");
}
private void btn_top_up_Click(object sender, EventArgs e)
{
MyMethods.Method_2("text2");
}
private void btn_down_Click(object sender, EventArgs e)
{
MyMethods.Method_2("text3");
}
private void btn_top_down_Click(object sender, EventArgs e)
{
MyMethods.Method_2("text4");
}
public static class MyMethods
{
public static void Method_1(string text) {...}
public static void Method_2(string text) {...}
}
}
}
As you can see I have a quite a number of click events so i'm curious if I can group them all in another c# file or a class or something
In your code-behind, declare a common method you want to call when any of the above buttons fire the Click event.
private void CommonClick(object sender, EventArgs e)
{
}
Now in your Properties window for each button, you can assign this event handler for all buttons:
Now when any of the buttons are clicked this same event handler is called.
If you want to know which button is clicked, you can either use button Name or even the Tag property.
Let's say we assign a separate unique Tag for each button. Tag is a property you can see in the property window for each button (and most controls).
Then you can use a switch-case statement in your code to identify which button was clicked.
private void CommonClick(object sender, EventArgs e)
{
switch (((Button)sender).Tag)
{
case "B1":
break;
case "B2":
break;
}
}
Above, B1, B2 etc are the tags I've assigned to each button.
usually in the form designer you dblclick on the empty "click" event property to generate new method as btn_..._Click(object sender, EventArgs e).
instead you can select existed method, so multiple buttons can call the same method:
Then in the called Method you can check which control trigger this event:
private void button1_Click(object sender, EventArgs e)
{
if (sender == button2)
{
// ....
}
if (sender == button1)
{
// ....
}
}
I have a form with 6 buttons. These buttons serve to increase/decrease tha value of the respective textbox. Now I'm trying to "animate" the buttons. I want to get another effect on the button when the mouse is over him.
To do that, I have two diferent images in Resources and I am doing this code:
private void btnHoursDown_MouseHover(object sender, EventArgs e) {
btnHoursDown.Image = Game_Helper.Properties.Resources.DownHover;
}
private void btnHoursDown_MouseLeave(object sender, EventArgs e) {
btnHoursDown.Image = Game_Helper.Properties.Resources.Down;
}
This works fine. My question is: it wouldn't be wise to create a class (ButtonBehaviour.cs) and put this code in that class?
So I would have something like this:
ButtonBehaviour buttonBehaviour = new ButtonBehaviour();
private void btnHoursDown_MouseHover(object sender, EventArgs e) {
buttonBehaviour.buttonDownHover();
}
private void btnHoursDown_MouseLeave(object sender, EventArgs e) {
buttonBehaviour.buttonDownLeave();
}
And the class should be:
public class ButtonBehaviour {
public void buttonDownHover() {
// code
}
public void buttonDownLeave() {
// code
}
}
How can I create this Class Behaviour and make the buttons adapt this Behaviour?
if one effect should be applied for all buttons, try to add the same event handlers to them
private void btn_MouseHover(object sender, EventArgs e)
{
(sender as Button).Image = Game_Helper.Properties.Resources.DownHover;
}
private void btn_MouseLeave(object sender, EventArgs e)
{
(sender as Button).Image = Game_Helper.Properties.Resources.Down;
}
button which raised event is available via sender variable
this way you avoid code duplication for every button. creating a ButtonBehaviour or CustomButton is probably an over-engineering unless you need them in many forms
First, pardon my new-ness, I just started coding class recently. Now, upon startup, I want parts of my form (c#) to not be shown, however when I put
NameDisplay.Visible = false;
(NameDisplay being the label I wish to hide) into my Form1.cs it gives me the error of that it is a 'field' being used as a 'type'. How do I correct this, and apply to other object types (buttons, textboxes, etc?)
EDIT 1-
Code- as it stands
namespace ATM
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
Label NameDisplay;
NameDisplay.Visible = false;
private void Form1_Load(object sender, EventArgs e)
{
}
private void StartButton_Click(object sender, EventArgs e)
{
}
private void NameDisplay_Click(object sender, EventArgs e)
{
}
private void textBox2_TextChanged(object sender, EventArgs e)
{
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
}
Remove Label NameDisplay;, and place NameDisplay.Visible = false; into your FormLoad event.
The loading of a form is an event just like clicking a button, and will execute the code like so.
Also, when I hide labels, I use .Hide(), but I believe that only works on WinForms.
Hope this helps!
You need to drag and drop the Label on the form and object will be created and initialized automatically in InitializeComponent.
In the form constructor (after InitializeComponent function) or Form_Load event, you may set the visibility to false
For example:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
NameDisplay.Visible = false;
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void StartButton_Click(object sender, EventArgs e)
{
}
private void NameDisplay_Click(object sender, EventArgs e)
{
}
private void textBox2_TextChanged(object sender, EventArgs e)
{
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
I have a event method
private void button1_Click_1(object sender, EventArgs e)
with some code in it. There I want to use a variable from another event method called
public void textBox2_TextChanged(object sender, EventArgs e)
so if a user writes a number it gets saved in a variable in the second method and i want to use this variable in the first method where a button gets clicked. How do I pass it?
Save it as a field of your form class. You can then write it in one event handler and read it in another:
public partial class MyForm
{
private string _someValue = null;
public void TextBox2_TextChanged(object sender, EventArgs e)
{
_someValue = "Some New Value";
}
public void Button1_Click(object sender, EventArgs e)
{
if (_someValue != null)
{
// ...
}
}
}
Though perhaps you can just read TextBox2.Text in the second method.
I am having a problem in calling multiple buttons at the same time because each buttons works a different process there are more than 78 folders.
I want to call all the buttons at the same time in a single button called button4. Now it's calling button1 only and not working for button2.
Is there any way to call these buttons at the same time?
My code is:
private void button4_Click_1(object sender, EventArgs e)
{
button1.PerformClick();
button2.PerformClick();
}
Thanks in Advance.
You should in general not perform UI-style clicks on other buttons in order to invoke their behaviour.
Just call the respective event handling methods of the buttons you would like to "click".
example code:
private void button4_Click_1(object sender, EventArgs e)
{
button1_Click_1(null, EventArgs.Empty);
button2_Click_1(null, EventArgs.Empty);
// and so on
}
You should refactor the other events to call well-named methods.
Say button1 does some initialization; it should look like this:
private void button1_Click(object sender, EventArgs e)
{
Initialize();
}
Say button2 finalizes that intialization; it should look like this:
private void button2_Click(object sender, EventArgs e)
{
FinalizeInitialization();
}
Then if button4 does all of this; it should look like this:
private void button4_Click(object sender, EventArgs e)
{
Initialize();
FinalizeInitialization();
WhateverElseButton4ShouldDo();
}
Under most circumstances, you shouldn't call PerformClick() at all. Instead, you should call the same methods your event handlers call. So, if clicking button 3 should behave as click clicking button 1 and then button 2, you should have code like this:
private void button1_Click(object sender, EventArgs e)
{
SomeAction();
}
private void button2_Click(object sender, EventArgs e)
{
AnotherAction();
}
private void button3_Click(object sender, EventArgs e)
{
SomeAction();
AnotherAction();
}
(As a side note, your buttons should have descriptive names, not button1 and the like.)
We can't say what those button click handlers do. So it's hard to say what's wrong. But try moving the code away from button click handlers. Create some class that contains code that should run after button click. Then call this class' methods from button click handlers. It will be easier to debug and test that code.
public class ButtonActions
{
public void DoSomething() {...}
public void DoSomething2() {...}
public void DoSomething3() {...}
public void DoAll()
{
DoSomething();
DoSomething2();
DoSomething3();
}
}
// here instead of clicking all buttons call method that does it all
protected void button_Click(object sender, EventArgs e)
{
var buttonActions = new ButtonActions();
buttonActions.DoAll();
}