Hi there.

How can I change the background color of a textbox when it gets the focus?

I can handle the "Enter" event and do this
private void txtDummie_Enter(object sender, EventArgs e) {

txtDummie.BackColor=Color.Red;

}

But how can I use this code to work with all textboxes in form? How can I
use "sender" argument?

Thanks in advance.

Regards,

Marco

Marco,

First, you would change your code to this:

((TextBox) sender).BackColor = Color.Red;

Then, on your form, you would cycle through all the TextBox controls
(the Controls collection will help you with this, just use the as operator
to determine if the control is a textbox) and then attach that method to the
Enter event handler.

You might want to make sure you attach another event handler to change
the color back when the textbox loses focus.


--
- Nicholas Paldino [.NET/C# MVP]
- (E-Mail Removed)

"Marco Pais" <marco.pais[at]gmail.com> wrote in message
news:(E-Mail Removed)...
> Hi there.
>
> How can I change the background color of a textbox when it gets the focus?
>
> I can handle the "Enter" event and do this
> private void txtDummie_Enter(object sender, EventArgs e) {
>
> txtDummie.BackColor=Color.Red;
>
> }
>
> But how can I use this code to work with all textboxes in form? How can I
> use "sender" argument?
>
> Thanks in advance.
>
> Regards,
>
> Marco
>
>

Hi there.

Thanks for the reply.

I'm not sure I understand "...just use the as operator...".

I think I must use something with "+=" bu I don't know how...

Thanks

"Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)> escreveu
na mensagem news:(E-Mail Removed)...
> Marco,
>
> First, you would change your code to this:
>
> ((TextBox) sender).BackColor = Color.Red;
>
> Then, on your form, you would cycle through all the TextBox controls
> (the Controls collection will help you with this, just use the as operator
> to determine if the control is a textbox) and then attach that method to
> the Enter event handler.
>
> You might want to make sure you attach another event handler to change
> the color back when the textbox loses focus.
>
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> - (E-Mail Removed)
>
> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
> news:(E-Mail Removed)...
>> Hi there.
>>
>> How can I change the background color of a textbox when it gets the
>> focus?
>>
>> I can handle the "Enter" event and do this
>> private void txtDummie_Enter(object sender, EventArgs e) {
>>
>> txtDummie.BackColor=Color.Red;
>>
>> }
>>
>> But how can I use this code to work with all textboxes in form? How can I
>> use "sender" argument?
>>
>> Thanks in advance.
>>
>> Regards,
>>
>> Marco
>>
>>
>
>

Marco,

When cycling through the Controls collection, you want to do something
like this:

foreach (Control control in myForm.Controls)
{
// The textbox control.
TextBox textBox = control as TextBox;

// If not null, set the handler.
if (textBox != null)
{
// Set the handler.
textBox.Enter += OnTextBoxEnter;
}
}

Of course OnTextBoxEnter is the method that sets the color to red. You
could use anonymous methods in C# 2.0 or a lambda expression in C# 3.0 to
make it even simpler.


--
- Nicholas Paldino [.NET/C# MVP]
- (E-Mail Removed)

"Marco Pais" <marco.pais[at]gmail.com> wrote in message
news:(E-Mail Removed)...
> Hi there.
>
> Thanks for the reply.
>
> I'm not sure I understand "...just use the as operator...".
>
> I think I must use something with "+=" bu I don't know how...
>
> Thanks
>
> "Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)>
> escreveu na mensagem news:(E-Mail Removed)...
>> Marco,
>>
>> First, you would change your code to this:
>>
>> ((TextBox) sender).BackColor = Color.Red;
>>
>> Then, on your form, you would cycle through all the TextBox controls
>> (the Controls collection will help you with this, just use the as
>> operator to determine if the control is a textbox) and then attach that
>> method to the Enter event handler.
>>
>> You might want to make sure you attach another event handler to change
>> the color back when the textbox loses focus.
>>
>>
>> --
>> - Nicholas Paldino [.NET/C# MVP]
>> - (E-Mail Removed)
>>
>> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
>> news:(E-Mail Removed)...
>>> Hi there.
>>>
>>> How can I change the background color of a textbox when it gets the
>>> focus?
>>>
>>> I can handle the "Enter" event and do this
>>> private void txtDummie_Enter(object sender, EventArgs e) {
>>>
>>> txtDummie.BackColor=Color.Red;
>>>
>>> }
>>>
>>> But how can I use this code to work with all textboxes in form? How can
>>> I use "sender" argument?
>>>
>>> Thanks in advance.
>>>
>>> Regards,
>>>
>>> Marco
>>>
>>>
>>
>>
>
>

Ok...

I'm using this:

foreach (Control control in this.Controls)

{

TextBox textBox = control as TextBox;

if (textBox != null){

textBox.Enter += delegate

{

//CHANGE BG COLOR

};

}

}

How can I know wich textbox must I change background color? How can I know
wich sender has triggered the event?

Thanks.

"Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)> escreveu
na mensagem news:(E-Mail Removed)...
> Marco,
>
> When cycling through the Controls collection, you want to do something
> like this:
>
> foreach (Control control in myForm.Controls)
> {
> // The textbox control.
> TextBox textBox = control as TextBox;
>
> // If not null, set the handler.
> if (textBox != null)
> {
> // Set the handler.
> textBox.Enter += OnTextBoxEnter;
> }
> }
>
> Of course OnTextBoxEnter is the method that sets the color to red. You
> could use anonymous methods in C# 2.0 or a lambda expression in C# 3.0 to
> make it even simpler.
>
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> - (E-Mail Removed)
>
> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
> news:(E-Mail Removed)...
>> Hi there.
>>
>> Thanks for the reply.
>>
>> I'm not sure I understand "...just use the as operator...".
>>
>> I think I must use something with "+=" bu I don't know how...
>>
>> Thanks
>>
>> "Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)>
>> escreveu na mensagem news:(E-Mail Removed)...
>>> Marco,
>>>
>>> First, you would change your code to this:
>>>
>>> ((TextBox) sender).BackColor = Color.Red;
>>>
>>> Then, on your form, you would cycle through all the TextBox controls
>>> (the Controls collection will help you with this, just use the as
>>> operator to determine if the control is a textbox) and then attach that
>>> method to the Enter event handler.
>>>
>>> You might want to make sure you attach another event handler to
>>> change the color back when the textbox loses focus.
>>>
>>>
>>> --
>>> - Nicholas Paldino [.NET/C# MVP]
>>> - (E-Mail Removed)
>>>
>>> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
>>> news:(E-Mail Removed)...
>>>> Hi there.
>>>>
>>>> How can I change the background color of a textbox when it gets the
>>>> focus?
>>>>
>>>> I can handle the "Enter" event and do this
>>>> private void txtDummie_Enter(object sender, EventArgs e) {
>>>>
>>>> txtDummie.BackColor=Color.Red;
>>>>
>>>> }
>>>>
>>>> But how can I use this code to work with all textboxes in form? How can
>>>> I use "sender" argument?
>>>>
>>>> Thanks in advance.
>>>>
>>>> Regards,
>>>>
>>>> Marco
>>>>
>>>>
>>>
>>>
>>
>>
>
>

On Jan 9, 6:59 am, "Marco Pais" <marco.pais[at]gmail.com> wrote:
> Hi there.
>
> How can I change the background color of a textbox when it gets the focus?
>
> I can handle the "Enter" event and do this
> private void txtDummie_Enter(object sender, EventArgs e) {
>
> txtDummie.BackColor=Color.Red;
>
> }
>
> But how can I use this code to work with all textboxes in form? How can I
> use "sender" argument?
>
> Thanks in advance.
>
> Regards,
>
> Marco

Actually, it's even easier than the suggestions from other threads...

Instead of iterating over each control on your form, simply add one
event handler like so:
private void OnTextBoxEnter(object sender, EventArgs e)
{
((TextBox)sender).BackColor = Color.Red;
}

Then, make sure each text box subscribes to this event handler method.

Cheers,

Greg

Marco,

You need to adjust the code like this:

textBox.Enter += delegate(object sender, EventArgs eventArgs)
{
((TextBox) sender).BackColor = Color.Red;
};


--
- Nicholas Paldino [.NET/C# MVP]
- (E-Mail Removed)

"Marco Pais" <marco.pais[at]gmail.com> wrote in message
news:%(E-Mail Removed)...
> Ok...
>
> I'm using this:
>
> foreach (Control control in this.Controls)
>
> {
>
> TextBox textBox = control as TextBox;
>
> if (textBox != null){
>
> textBox.Enter += delegate
>
> {
>
> //CHANGE BG COLOR
>
> };
>
> }
>
> }
>
> How can I know wich textbox must I change background color? How can I know
> wich sender has triggered the event?
>
> Thanks.
>
> "Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)>
> escreveu na mensagem news:(E-Mail Removed)...
>> Marco,
>>
>> When cycling through the Controls collection, you want to do something
>> like this:
>>
>> foreach (Control control in myForm.Controls)
>> {
>> // The textbox control.
>> TextBox textBox = control as TextBox;
>>
>> // If not null, set the handler.
>> if (textBox != null)
>> {
>> // Set the handler.
>> textBox.Enter += OnTextBoxEnter;
>> }
>> }
>>
>> Of course OnTextBoxEnter is the method that sets the color to red.
>> You could use anonymous methods in C# 2.0 or a lambda expression in C#
>> 3.0 to make it even simpler.
>>
>>
>> --
>> - Nicholas Paldino [.NET/C# MVP]
>> - (E-Mail Removed)
>>
>> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
>> news:(E-Mail Removed)...
>>> Hi there.
>>>
>>> Thanks for the reply.
>>>
>>> I'm not sure I understand "...just use the as operator...".
>>>
>>> I think I must use something with "+=" bu I don't know how...
>>>
>>> Thanks
>>>
>>> "Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)>
>>> escreveu na mensagem news:(E-Mail Removed)...
>>>> Marco,
>>>>
>>>> First, you would change your code to this:
>>>>
>>>> ((TextBox) sender).BackColor = Color.Red;
>>>>
>>>> Then, on your form, you would cycle through all the TextBox controls
>>>> (the Controls collection will help you with this, just use the as
>>>> operator to determine if the control is a textbox) and then attach that
>>>> method to the Enter event handler.
>>>>
>>>> You might want to make sure you attach another event handler to
>>>> change the color back when the textbox loses focus.
>>>>
>>>>
>>>> --
>>>> - Nicholas Paldino [.NET/C# MVP]
>>>> - (E-Mail Removed)
>>>>
>>>> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
>>>> news:(E-Mail Removed)...
>>>>> Hi there.
>>>>>
>>>>> How can I change the background color of a textbox when it gets the
>>>>> focus?
>>>>>
>>>>> I can handle the "Enter" event and do this
>>>>> private void txtDummie_Enter(object sender, EventArgs e) {
>>>>>
>>>>> txtDummie.BackColor=Color.Red;
>>>>>
>>>>> }
>>>>>
>>>>> But how can I use this code to work with all textboxes in form? How
>>>>> can I use "sender" argument?
>>>>>
>>>>> Thanks in advance.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Marco
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>

Finally got it to work!

Thanks a lot!

Regards.

"Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)> escreveu
na mensagem news:eB%(E-Mail Removed)...
> Marco,
>
> You need to adjust the code like this:
>
> textBox.Enter += delegate(object sender, EventArgs eventArgs)
> {
> ((TextBox) sender).BackColor = Color.Red;
> };
>
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> - (E-Mail Removed)
>
> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
> news:%(E-Mail Removed)...
>> Ok...
>>
>> I'm using this:
>>
>> foreach (Control control in this.Controls)
>>
>> {
>>
>> TextBox textBox = control as TextBox;
>>
>> if (textBox != null){
>>
>> textBox.Enter += delegate
>>
>> {
>>
>> //CHANGE BG COLOR
>>
>> };
>>
>> }
>>
>> }
>>
>> How can I know wich textbox must I change background color? How can I
>> know wich sender has triggered the event?
>>
>> Thanks.
>>
>> "Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)>
>> escreveu na mensagem news:(E-Mail Removed)...
>>> Marco,
>>>
>>> When cycling through the Controls collection, you want to do
>>> something like this:
>>>
>>> foreach (Control control in myForm.Controls)
>>> {
>>> // The textbox control.
>>> TextBox textBox = control as TextBox;
>>>
>>> // If not null, set the handler.
>>> if (textBox != null)
>>> {
>>> // Set the handler.
>>> textBox.Enter += OnTextBoxEnter;
>>> }
>>> }
>>>
>>> Of course OnTextBoxEnter is the method that sets the color to red.
>>> You could use anonymous methods in C# 2.0 or a lambda expression in C#
>>> 3.0 to make it even simpler.
>>>
>>>
>>> --
>>> - Nicholas Paldino [.NET/C# MVP]
>>> - (E-Mail Removed)
>>>
>>> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
>>> news:(E-Mail Removed)...
>>>> Hi there.
>>>>
>>>> Thanks for the reply.
>>>>
>>>> I'm not sure I understand "...just use the as operator...".
>>>>
>>>> I think I must use something with "+=" bu I don't know how...
>>>>
>>>> Thanks
>>>>
>>>> "Nicholas Paldino [.NET/C# MVP]" <(E-Mail Removed)>
>>>> escreveu na mensagem news:(E-Mail Removed)...
>>>>> Marco,
>>>>>
>>>>> First, you would change your code to this:
>>>>>
>>>>> ((TextBox) sender).BackColor = Color.Red;
>>>>>
>>>>> Then, on your form, you would cycle through all the TextBox
>>>>> controls (the Controls collection will help you with this, just use
>>>>> the as operator to determine if the control is a textbox) and then
>>>>> attach that method to the Enter event handler.
>>>>>
>>>>> You might want to make sure you attach another event handler to
>>>>> change the color back when the textbox loses focus.
>>>>>
>>>>>
>>>>> --
>>>>> - Nicholas Paldino [.NET/C# MVP]
>>>>> - (E-Mail Removed)
>>>>>
>>>>> "Marco Pais" <marco.pais[at]gmail.com> wrote in message
>>>>> news:(E-Mail Removed)...
>>>>>> Hi there.
>>>>>>
>>>>>> How can I change the background color of a textbox when it gets the
>>>>>> focus?
>>>>>>
>>>>>> I can handle the "Enter" event and do this
>>>>>> private void txtDummie_Enter(object sender, EventArgs e) {
>>>>>>
>>>>>> txtDummie.BackColor=Color.Red;
>>>>>>
>>>>>> }
>>>>>>
>>>>>> But how can I use this code to work with all textboxes in form? How
>>>>>> can I use "sender" argument?
>>>>>>
>>>>>> Thanks in advance.
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Marco
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
>

If I am not mistaken, that is what the other threads suggest. =)


--
- Nicholas Paldino [.NET/C# MVP]
- (E-Mail Removed)

"Greg" <(E-Mail Removed)> wrote in message
news:cd462477-7d03-4878-b72a-(E-Mail Removed)...
> On Jan 9, 6:59 am, "Marco Pais" <marco.pais[at]gmail.com> wrote:
>> Hi there.
>>
>> How can I change the background color of a textbox when it gets the
>> focus?
>>
>> I can handle the "Enter" event and do this
>> private void txtDummie_Enter(object sender, EventArgs e) {
>>
>> txtDummie.BackColor=Color.Red;
>>
>> }
>>
>> But how can I use this code to work with all textboxes in form? How can I
>> use "sender" argument?
>>
>> Thanks in advance.
>>
>> Regards,
>>
>> Marco
>
> Actually, it's even easier than the suggestions from other threads...
>
> Instead of iterating over each control on your form, simply add one
> event handler like so:
> private void OnTextBoxEnter(object sender, EventArgs e)
> {
> ((TextBox)sender).BackColor = Color.Red;
> }
>
> Then, make sure each text box subscribes to this event handler method.
>
> Cheers,
>
> Greg