issue with textbox event handlers - c#

I am still learning how to do with event handler. What I want is: When I click the txtMonday to get focused, then I click the remove button to clear this selected textbox. Problem is: when I click the remove button for the selected textbox, all the unselected textboxes are clear. I only want to remove the selected textbox. How to solve this problem? Your code example much appreciated. Thanks! I am using WPF and C#.
private void btnRemoveClick(object sender, RoutedEventArgs e)
{
TextBox text = new TextBox();
text.GotFocus += new RoutedEventHandler(txtMonday_GotFocus);
txtMonday.Clear();
text.GotFocus += new RoutedEventHandler(txtTuesday_GotFocus);
txtTuesday.Clear();
}
private void txtMonday_GotFocus(object sender, RoutedEventArgs e)
{
}
private void txtTuesday_GotFocus(object sender, RoutedEventArgs e)
{
}

This should do what you want. I suggest you do some more studying about C# though, as your code shows some fundamental misunderstandings.
//you'll need a variable to store the last focused textbox.
TextBox txtLast;
public MainWindow()
{
InitializeComponent();
//add an event for all the textboxes so that you can track when one of them gets focus.
txtSunday.GotFocus += txt_GotFocus;
txtMonday.GotFocus += txt_GotFocus;
txtTuesday.GotFocus += txt_GotFocus;
txtWednesday.GotFocus += txt_GotFocus;
txtThursday.GotFocus += txt_GotFocus;
txtFriday.GotFocus += txt_GotFocus;
txtSaturday.GotFocus += txt_GotFocus;
//default to clearing sunday to avoid exception
//you could also let it clear a new TextBox(), but this is wasteful. Ideally,
//you would handle this case gracefully with an if statement, but I will leave that
//as an exercise to the reader.
txtLast = txtSunday;
}
private void txt_GotFocus(object sender, RoutedEventArgs e)
{
//whenever you click a textbox, this event gets called.
//e.source is the textbox, but since it is is just an "Object" we need to cast it to a TextBox
txtLast = e.Source as TextBox;
}
private void Button_Click(object sender, RoutedEventArgs e)
{
//this will clear the textbox which last had focus. If you click a button, the current textbox loses focus.
txtLast.Clear();
}

Related

Why I can not change focus?

Im making a calculator.and for the buttons that type numbers, I wrote a condition that if the focus was on text box 1, it would enter the text there, if not, it would enter text box 2. But unfortunately the code does not work and I dont understand the problem.
(WindosForm(.Net framework))
if (textBox1.Focus() == true)
{
textBox1.Text = textBox1.Text + "1";
}
else
{
textBox2.Text = textBox2.Text + "1";
}
Subscribe to "Enter" event for your two textbox and save it. Use the same method for the two textboxes.
TextBox focusedTB;
private void textBox_Enter(object sender, EventArgs e)
{
focusedTB = sender as TextBox;
}
...
this.textBox1.Enter += new System.EventHandler(this.textBox_Enter);
...
this.textBox2.Enter += new System.EventHandler(this.textBox_Enter);
Now you know the last textbox that got focus.
private void button1_Click(object sender, EventArgs e)
{
focusedTB.Text += "1";
}
Your code appears to be attempting to check if the control is focused. The correct way to do that is:
if (textBox1.Focused)
{
// Because 'Focused' is a property. 'Focus()' is a method.
textBox1.Text = textBox1.Text + "1";
}
.
.
.
The answer to your question Why I can not change focus? is that textBox1 receives the focus every time you call this:
if (textBox1.Focus())
As mentioned in one of the comments, here's how the Focus method works:
// Summary:
// Sets input focus to the control.
//
// Returns:
// true if the input focus request was successful; otherwise, false.
[EditorBrowsable(EditorBrowsableState.Advanced)]
public bool Focus();
Note: This is a copy-paste of metadata that you can look at by right-clicking over Focus() in your code and selecting Go to Definition then expanding the definition.
I think you talk about Windows Form ?
You cannot manage like this but use event "Enter" of your textboxes, when you click inside the textbox, you give the focus to this textbox and you can do anything inside. Here I put the right focuses TextBox in a variable.
private TextBox _textBoxFocused; //this is always the righ TextBox
private void textBox1_Enter(object sender, EventArgs e)
{
_textBoxFocused = textBox1;
}
private void textBox2_Enter(object sender, EventArgs e)
{
_textBoxFocused = textBox2;
}

Use enter key to send text to a rich text box

I am currently using winforms and I want to send the text from a textbox to a rich text box by pressing enter. Here is the code I currently have
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter)
{
richTextBox1.Text = textBox1.Text;
e.Handled = true;
}
}
What am I missing? Thanks in advance.
Did you subscribe to the event KeyDown? You can add a break point in textBox1_KeyDown to check it.
If the break point is not triggered, you can delete textBox1_KeyDown and double click the Button to re-generate it. Then will subscribe to the event "KeyDown" automatically.
Another way is that you can subscribe to events through code.
public Form1()
{
InitializeComponent();
textBox1.KeyDown += textBox1_KeyDown;
}

one Click event for multiple buttons with Text property

I want to make a click event for a bunch of buttons. The problem is that I want to use the button's Text, and pass it to a function. Now the click event is passed a object sender. When I tried changing that to Button sender, it gave errors. But I don't know how else I can work with the senders Text.
Here is the normal code, which gave a single error:
private void guess_Click(object sender, EventArgs e)
{
guess(sender.Text);
}
I changed it to this, which gave errors:
private void guess_Click(Button sender, EventArgs e)
{
guess(sender.Text);
}
Question:
How can I work with the Button's Text property within this click event, which is a single click_event for multiple buttons?
Step 1: You need to subscribe to the Button Click event of all your buttons to the same EventHandler. so that button click on all your Buttons will fire the same `Event Handler.
Step 2: You need to cast the object sender into Button and then access its Text property to get the Button Text.
Try This:
button1.Click += new System.EventHandler(MyButtonClick);
button2.Click += new System.EventHandler(MyButtonClick);
button3.Click += new System.EventHandler(MyButtonClick);
private void MyButtonClick(object sender, EventArgs e)
{
Button btnClick = (Button)sender ;
guess(btnClick.Text);
}
Cast sender to type button.
Example:
private void guess_Click(object sender, EventArgs e)
{
guess(((Button)sender).Text);
}
You need to cast the sender object to the Button type and use that:
private void guess_Click(object sender, EventArgs e)
{
Button senderBtn = senderBtn as Button;
if(senderBtn != null)
{
guess(senderBtn.Text);
}
}

Dynamically create buttons and add events to it

I need to dynamically create buttons (one for loop) and add "onClick" and "doubuleClick" events on it.
I did it like this:
Button bt = new Button();
bt.Click += bt_Click;
bt.DoubleClick += bt_DoubleClick;
private void bt_Click(object sender, EventArgs e)
{
label1.Text = this.Text;
}
private void bt_DoubleClick(object sender, EventArgs e)
{
//some code
}
First: My "bt_Click" method gets "main form" text in "label1". In debugger I see that sender is a button. What is wrong with it?
Second: My "bt_DoubleClick" event do not react at all, am I doing something wrong here?
Any help is appreciated.
You should cast sender to Button to get the bt.Text:
Button bt = new Button();
bt.Click += bt_Click;
bt.Text = "click me";
bt.Location = new Point(100,100);
this.Controls.Add(bt);
private void bt_Click(object sender, EventArgs e)
{
label1.Text = (sender as Button).Text;
}
Buttons doesn't react to double click event. You can read it here in detail.
In response to the first question, if I understand you correctly, in this.Text, this refers to the form because the method bt_Click is a member of the Main Form class. I think you might have meant to do:
private void bt_Click(object sender, EventArgs e)
{
label1.Text = (Button)sender.Text;
}
Second: Is this just a case of the bt_Click handler firing twice?
The easiest way to do this it is to use "datagrid".
Datagread has the great support for all events and for organization of items (image, text and so on).
I have made "save" or "open" dialog form to browse content from remote SFTP server, very easy with datagrad, but I had a problem to do it with buttons or labels.

How to connect text change event in multiple text boxes to a single method (C#)?

When I double click on my text boxes in the designed, it creates a method auto-magically for me. Since I wish the same things to occur in any of the cases, I simply call an auxiliary method from each, like in the code below.
private void TextBox_1_TextChanged(object sender, EventArgs e)
{
TextChanged();
}
private void TextBox_2_TextChanged(object sender, EventArgs e)
{
TextChanged();
}
private void TextChanged(object sender, EventArgs e) { ... }
Now I'd like to know if there's a way (other than going into my design file (which, according to the information in it, shouldn't be attempted to) to connect the actions listeners to the same method and skip the detour via the automatically generated ones.
On the designer page go to the events tab, find the event you are looking for (TextChanged) and manually enter the name of the event handler you wish them all to use.
I usually proceed like this in my projects, if controls are not going to change at runtime (i.e. if all controls in the form are added at design time):
// this is the container's ctor
public MyForm()
{
TextBox1.TextChanged += new EventHandler(UniqueHandler);
TextBox2.TextChanged += new EventHandler(UniqueHandler);
...
TextBoxN.TextChange += new EventHandler(UniqueHandler);
}
void UniqueHandler(object sender, EventArgs e)
{
TextBox source = (sender as TextBox);
// handle the event!
}
If controls will change, it's actually quite similar, it just doesn't happen in the ctor but on-site:
// anywhere in the code
TextBox addedAtRuntime = new TextBox();
addedAtRuntime.TextChanged += new EventHandler(UniqueHandler);
MyForm.Controls.Add(addedAtRuntime);
// code goes on, the new textbox will share the handler
In the properties fold-out (most often to the right of your screen) you should have a thunder icon. That's where all the events are referable.
If you don't see the properties, select the regarded component (the text box in your case), right-mouse it and pick "properties" in the context menu.
You can do it by this way:
void btn1_onchange(object sender, EventArgs e)
{
MessageBox.Show("Number One");
}
void btn1_onchange2(object sender, EventArgs e){
MessageBox.Show("Number Two");
}
public MyForm() {
Button btn1 = new Button();
btn1.Text = "Click Me";
this.Controls.Add(btn1);
btn1.TextChange += new EventHandler(btn1_onchange);
btn1.TextChange += new EventHandler(btn1_onchange2);
}
You could do it in designer view. Instead of double-clicking on an element - go to your buttons' properties, select events tab and then put a proper handler name for adequate event. Voila!
Follow these steps:
Go to the InitializeComponent().
There are three events attached to each text box.
There you shoud be able to see the following.
this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
this.textBox2.TextChanged += new System.EventHandler(this.textBox2_TextChanged);
Replace this with
this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
this.textBox2.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
And then remove the method below
private void TextBox_2_TextChanged(object sender, EventArgs e)
{
TextChanged();
}

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