Re: How to clear all textboxes on a form with a button - C# Discussion Boards

CAS, WPF & plugin question

9-Mar-08 19:27

Please read this[^].

Christian Graus - Microsoft MVP - C++

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Super Lloyd9-Mar-08 18:15

Super Lloyd

9-Mar-08 18:15

In my application I am able to load plugins, i.e. use reflection look in an assembly for classes implementing a given interface and instantiate them.

I would like these plugins to run with restricted right.
Like they are not able to access the file system, etc....
How could I do that?

Also, from some prelimiary reading it seems I will have to run thess plugin in different AppDomain, but these plugin need to create some WPF.Controls I'm adding to my main form's visual tree hierachy.
Is it possible to do that? I mean add in the UITree a WPF.Control which is from a different AppDomain?
(I foresee a dispatcher problem)

Any tip? (or maybe I don't need to run my plugin in a different AppDomain after all?)

how to display crystal reports at the client PC

Sadaf Naeem9-Mar-08 18:07

Sadaf Naeem

9-Mar-08 18:07

I have used crystal reports in C# .net in my application

when I run my application on my client PC where Visual Studio 2005 IDE is not installed, the forms having crystal report do not display.

The .net framework 2.0 has already been installed on the coimputers but I was wondering if there is any other also required to display crystal reports.

Sadaf

Re: how to display crystal reports at the client PC

Ravenet9-Mar-08 18:23

How to clear all textboxes on a form with a button

9-Mar-08 18:23

Ok can can

Please check ur client pc for MS report viewer is installed?

thanks

Cheers,Earn and Enjoy
RRave
MCTS,MCPD
http://ravesoft.blogspot.com

Jacob Dixon9-Mar-08 16:49

Re: How to clear all textboxes on a form with a button

9-Mar-08 16:49

How come this doesn't work when you click the button?

foreach (Control txt in this.Controls)
{
    if (txt.GetType() == typeof(System.Windows.Forms.TextBox))
    {
        txt.Text = "";
    }
}

I had another one that using a for statement instead of foreach and it won't work either.. here it is:

for (int i = 0; i < this.Controls.Count; i++)
{
    if (this.Controls[i] is TextBox)
    {
        this.Controls[i].Text = "";
    }
}

KaptinKrunch9-Mar-08 16:57

KaptinKrunch

9-Mar-08 16:57

Try casting the control to a textbox then reference its properties.

Just because we can; does not mean we should.

Re: How to clear all textboxes on a form with a button

Jacob Dixon9-Mar-08 17:05

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:05

Uhm what do you mean by that?

KaptinKrunch9-Mar-08 17:10

KaptinKrunch

9-Mar-08 17:10

Here's an example. You need to "cast" it to the type of control you expect it to be and not the control object it self. Simply comparing its types wont give you access to the, in this case a TextBox, properties like .Text and so forth.

foreach (Control txt in this.Controls)
{
if (txt.GetType() == typeof(System.Windows.Forms.TextBox))
{
TextBox txtbx = (TextBox)txt;
txtbx.Text = "";
}
}

Just because we can; does not mean we should.

Re: How to clear all textboxes on a form with a button

Jacob Dixon9-Mar-08 17:20

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:20

Ok I see, but it still isn't working.. its weird because I have this:

for (int i = 0; i < this.Controls.Count; i++)
{
    if (this.Controls[i] is TextBox)
    {
        this.Controls[i].Text = "";
    }
}

under a listbox selection change committed and it works every time!

Christian Graus9-Mar-08 17:35

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:35

Jacob Dixon wrote:
for (int i = 0; i < this.Controls.Count; i++) { if (this.Controls[i] is TextBox) { this.Controls[i].Text = ""; } }

Instead of 'is', use 'as'.

TextBox tb = Controls[i] as TextBox;

if (tb != null)
{
// whatever
}

If the property you use exists on the Control class, then your code will work, if you try to use properties that are specific to the class you failed to cast to, it will not.

Jacob Dixon9-Mar-08 17:42

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:42

So if your talking about this it still doesn't work:

private void button10_Click(object sender, EventArgs e)
{
        for (int i = 0; i < this.Controls.Count; i++)
        {
            TextBox tb = Controls[i] as TextBox;

            if (tb != null)
            {
                tb.Text = "";
            }

        }

        // Clear all the combo boxes and richtextboxes on the form
        Phone2Listbox.Items.Clear();
        phoneListbox.Items.Clear();
        AuthPhone1Listbox.Items.Clear();
        AuthPhone2Listbox.Items.Clear();
        AuthPhone3Listbox.Items.Clear();
        MedAllergiesListbox.Items.Clear();
        MedPhoneListbox.Items.Clear();
        EmergPhoneListbox.Items.Clear();
        PaidToDateListbox.Items.Clear();
        richTextBox1.Clear();
        othercomments.Clear();
}

Is that what you were talking about?

Christian Graus9-Mar-08 19:28

Re: How to clear all textboxes on a form with a button

9-Mar-08 19:28

Yes, if that doesn't work, then this code just plain is not running, or something else is strange on your form.

KaptinKrunch9-Mar-08 17:48

KaptinKrunch

9-Mar-08 17:48

Both examples work under a button click event.

<br />
            foreach (Control txt in this.Controls)<br />
            {<br />
                if (txt.GetType() == typeof(System.Windows.Forms.TextBox))<br />
                {<br />
                    TextBox txtbx = (TextBox)txt;<br />
                    txtbx.Text = "";<br />
                }<br />
            } <br />
<br />
<br />
            for (int i = 0; i < this.Controls.Count; i++)<br />
            {<br />
                if (this.Controls[i] is TextBox)<br />
                {<br />
                    this.Controls[i].Text = "";<br />
                }<br />
            }

Difference between the two is that the first refers to a Control object. So you need to cast it to the TextBox control to gain access to the TextBox property?. Otherwise your setting the text of the control. Check it out in the debugger! In the second you reference the actual object and this exposes the objects, in this case a TextBox, .Text property.

Hope this helps.

Just because we can; does not mean we should.

Re: How to clear all textboxes on a form with a button

Christian Graus9-Mar-08 17:41

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:41

Also, 'it won't work' is not really a question. What does it do ? Does it compile ? What happens when you step through it in the debugger ? I suspect your real problem is not casting, as Control has a Text property, but you've not really done enough work to tell us what is going on, or to try and work out what's really happening.

My best guess is that this code is not running at all.

Jacob Dixon9-Mar-08 17:48

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:48

I am using the same thing on the listbox selection committed and it works..

I set some break points to see if it is doing anything.. I am not getting any errors at all.
I have about twenty textboxes and I see that it is clearing one text box. But it is not clearing any of the other ones.

Jacob Dixon9-Mar-08 17:51

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:51

actually it is clearing that one textbox and every item in a ListBox???

Ravenet9-Mar-08 17:50

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:50

Hi
Yes u way is rite,but chaneg ur code like this

foreach (Control txt in this.Controls)
{
if (txt as TextBox)
{
txt.Text = string.Empty;
this.Refresh();
}
}

I think this should be work for u.

thanks

Cheers,Earn and Enjoy
RRave
MCTS,MCPD
http://ravesoft.blogspot.com

Jacob Dixon9-Mar-08 17:54

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:54

That is doing the same thing... it clears a listbox, and a richtextbox but none of the regular text boxes

That one Textbox that it was clearing with the other codes I changed to a Label, because that is the only one that I wanted not to clear lol

So that is clearing all the items in a listbox, and the richtextbox, but not any of the other ones. I don't know whats going on.. I don't know what to see you.. I posted the exact code for the button click event

Ravenet9-Mar-08 17:58

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:58

Hi
Please give a clear picture ,wat are u trying?

once time say listbox, after say textbox?

So, So tell me, wat u r trying?

thanks

Cheers,Earn and Enjoy
RRave
MCTS,MCPD
http://ravesoft.blogspot.com

Jacob Dixon9-Mar-08 18:03

Re: How to clear all textboxes on a form with a button

9-Mar-08 18:03

Ok.. I have a button that is suppose to clear EVERY textbox on my form. That is what I am trying to accomplish! The buttons code is this:

This is EXACTLY what I have:

private void button10_Click(object sender, EventArgs e)
{
    foreach (Control txt in this.Controls)
    {
        if (txt is TextBox)
        {
            txt.Text = string.Empty;
            this.Refresh();
        }
    }


        // Clear all the combo boxes and richtextboxes on the form
        Phone2Listbox.Items.Clear();
        phoneListbox.Items.Clear();
        AuthPhone1Listbox.Items.Clear();
        AuthPhone2Listbox.Items.Clear();
        AuthPhone3Listbox.Items.Clear();
        MedAllergiesListbox.Items.Clear();
        MedPhoneListbox.Items.Clear();
        EmergPhoneListbox.Items.Clear();
        PaidToDateListbox.Items.Clear();
        richTextBox1.Clear();
        othercomments.Clear();
}

I am sorry that I said it was clearing a listbox, that is the code I have above that is clearing the textbox, and richtextbox. I'm tired, so sorry I said that.

The point is, is that it is not clearing the textboxes.. When I load my form I just type random crap in the text boxes and click my button (Clear All) and it doesn't clear the textboxes..

By the way I can't do:

if (txt as TextBox)

It has to be:

if (txt is TextBox)

The reason is, is because when you use the txt AS textbox it throws an exeception:

" Cannot implicity convert type 'System.Windows.Forms.Textbox' to 'bool' "

Ravenet9-Mar-08 18:07

Re: How to clear all textboxes on a form with a button

9-Mar-08 18:07

OK cool

can can

i'm directly typed that code in that post,and this is web applications?

Cheers,Earn and Enjoy
RRave
MCTS,MCPD
http://ravesoft.blogspot.com

Jacob Dixon9-Mar-08 17:58

Re: How to clear all textboxes on a form with a button

9-Mar-08 17:58

I'm not sure whats going on.. I don't understand why it is clearing the listbox and the richtextbox and not any of the other textboxes. Which it is suppost to see that it is a TextBox and for some reason it is clearing all the items in a listbox.

I've got to go to bed, sorry guys! Thanks for trying to help me out.. I will mess with it more tomorrow night after banging my head on the wall a couple of times lol.

Christian Graus9-Mar-08 18:01

Re: How to clear all textboxes on a form with a button

9-Mar-08 18:01

Next time, step through it in the debugger and let us know what you see. That's the missing ingredient here, that's why we can't work out what's going wrong.

Jacob Dixon9-Mar-08 18:08

Re: How to clear all textboxes on a form with a button

9-Mar-08 18:08

Ok I set break points. This is what going on for this code:

foreach (Control txt in this.Controls)
{
if (txt is TextBox) <-- BREAK HERE * txt is Textbox | false *
{
txt.Text = string.Empty;
this.Refresh();
}
}

It is saying false for every control that it loops through? That is all I can tell you because that is all I know..

Jacob Dixon9-Mar-08 18:10