Re: Whats wrong with this? - C# Discussion Boards

7-Apr-06 2:19

private void DeactivateControls(ControlCollection ctl)<br />
{<br />
<br />
	foreach (Control ctrl in ctl)<br />
	{<br />
		if (ctrl is MyTextBox)<br />
			((MyTextBox)(ctrl)).EnabledSpecial = false;<br />
<br />
		else<br />
			(ctrl).Enabled = false;<br />
<br />
		if (ctrl.HasChildren)<br />
			DeactivateControls(ctrl.Controls);<br />
	}<br />
}

MyTextBox.EnabledSpecial is still true after I try to set it to false in this method. What do I do wrong?

-- modified at 8:20 Friday 7th April, 2006

Colin Angus Mackay7-Apr-06 2:25

Colin Angus Mackay

7-Apr-06 2:25

That depends on what the property EnableSpecial does. Without seeing that code, who knows what is going on?

"On two occasions, I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question."
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livez7-Apr-06 2:28

7-Apr-06 2:28

I didnt show the enabledSpecial since I know that's not where the problem lies, it works in many other places.

Jon Hulatt7-Apr-06 3:17

7-Apr-06 3:17

If you know that that's not where the problem lies, and there's nothing wrong with the code you posted (except overuse of brackets), and you're sure there's a MyTextBox in the control tree, and you're sure you're calling the method, then obviously your code must work. So there's no problem.

using System.Beer;

livez7-Apr-06 3:25

7-Apr-06 3:25

well, all that is right except the no problem part =)

Guffa7-Apr-06 2:45

7-Apr-06 2:45

Do you call the method? How? Does the control that you want to change exist under the control collection you send to the method?

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livez7-Apr-06 3:04

7-Apr-06 3:04

this is how I call;

protected override void OnEnabledChanged(System.EventArgs e)<br />
{<br />
	if(this.Enabled)<br />
	{<br />
		this.Enabled = true;<br />
		ActivateControls(this.Controls);<br />
	}<br />
	else<br />
	{<br />
		this.Enabled = true;<br />
		DeactivateControls(this.Controls);	<br />
}

and yes, it exists. Ive debugged my way in there, and everything looks right except enabledspecial is still true after the setting to false.

Jon Hulatt7-Apr-06 3:28

7-Apr-06 3:28

Here's your problem. If you'd have debugged, you'd have spotted your OnEnabledChanged event getting fired twice when you disable the control.

picture when that event is called, and the control just got disable. therefore this.Enabled == false

Your else clause fires. So you reenable the control. This will cause your event to fire again, but this time you'll be activating the controls.

using System.Beer;

livez7-Apr-06 3:49

7-Apr-06 3:49

thanks for your response, you seem to be on to something.

Evaluating a value to a string

Judah Gabriel Himango7-Apr-06 4:05

Judah Gabriel Himango

7-Apr-06 4:05

In addition to what the other posters said, you are casting your object 2x, first by checking the type using the 'is' keyword, then casting it to that type. A better, more efficient way is to use the 'as' operator:

MyTextBox controlAsTextBox = ctrl as MyTextBox;
if(controlAsTextBox != null)
{
    ....
}

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Judah Himango

C# and MS Word?

kbalias7-Apr-06 1:59

kbalias

7-Apr-06 1:59

The user has many reports done in MS Word. The secretaries type the reports and then the managers have to read the reports and either approve them or refer them back for correction. After approval they need to be printed.

My initial idea is to do a windows application using C# and SQL Server. In the database I store the path to the report documents and this also allows me to add a column to this database table holding a flag, which will indicate whether the document needs to be corrected, has been approved, or can be printed. In that way when the application is started and the list of documents are displayed in ListView (for example) the user can see at first glance which documents are ready for printing, etc. The user can then also select which documents to list (i.e. the approved ones, the ones for printing, or the ones in the archive).

I have managed to write code that will open a document by opening MS Word from within the C# application. However that opens the document external to the C# application and this does not allow me to be able to set a flag once I have read/edited the document and closed MS Word. What I would like to do is open the word document onto my windows form (without losing the formatting) in some way and be able to edit it or even create a new one and still save it as a .doc document. Then once it was saved for example an option pops up whereby the document can be flagged as “Approved”, etc.

Is it possible doing it the way I have thought? Can you direct me to examples of how to get the document opened within the C# form? Any better ideas or suggestions will also be greatly appreciated.

Thanks.
Kobus

Re: C# and MS Word?

scoroop7-Apr-06 2:07

scoroop

7-Apr-06 2:07

i didn't read what this control can do but perhaps it helps...

http://www.codeproject.com/cs/miscctrl/winwordcontrol.asp

Bill - Go Steelers!7-Apr-06 1:58

Bill - Go Steelers!

7-Apr-06 1:58

public static StringBuilder ParseMultipleSelections(string parameterString)
{
CurrentDelimValues = searchParams[parameterString].ToString().Split('~');

}

// searchParams is a Hashtable
// I want to pass the string I'm looking for
// in the Hashtable so that
// the variable: parameterString
// is converted to the string

Much Thanks...

Guffa7-Apr-06 2:34

7-Apr-06 2:34

Did you post this only as information, or do you have a question also?

If you don't make
a line break every
other word, it's
much easier to
read what you
write.

What is it that you want to convert, and how?

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Bill - Go Steelers!7-Apr-06 2:49

Bill - Go Steelers!

7-Apr-06 2:49

To get the value in a Hashtable you use a string: Hashtable["myString"].ToString().

I want to be able to change "myString" to a variable so that I can create a method where "myString" can change based on the variable being passed.

Thanks again.

Guffa7-Apr-06 6:13

7-Apr-06 6:13

Yes, that is what you did in the code that you showed. Is there a problem with this?

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Bill - Go Steelers!7-Apr-06 8:51

Bill - Go Steelers!

7-Apr-06 8:51

I'll have to retest. I'm pretty sure I got an error. Since I'm up against a deadline, I just figured out a different way of accomplishing the same thing.

Thanks for your help.

type conversions

Jon Hulatt7-Apr-06 1:48

7-Apr-06 1:48

Hi All,

Given:-

class A
{
}

class DerivedFromA : A
{
}

If i have an instance of A, but i want to "upgrade it" to be a DerivedFromA, is there any way to do that? C# doesn't seem to allow conversion operators between derived types. The only other way I can see to do it is to have a method in DerivedFromA like this:-

public static DerivedFromA(A theInstance)
{}

which could then do the conversion. But that gives me access issues - i can't copy protected members from A to the new DerivedFromA instance.

Any ideas?

thanks

Jon

using System.Beer;

Guffa7-Apr-06 2:03

7-Apr-06 2:03

No, you can't cast an object to a class the inherits from the class of the object. You can only cast an object to any of it's base classes.

Jon Hulatt wrote:
i can't copy protected members from A to the new DerivedFromA instance.

Yes, you can. You can access any protected members from the derived class. That is exactly what the protected keyword does, it allows access only from members of the class and from members of any derived classes.

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Jon Hulatt7-Apr-06 3:10

7-Apr-06 3:10

Guffa wrote:
Yes, you can. You can access any protected members from the derived class. That is exactly what the protected keyword does, it allows access only from members of the class and from members of any derived classes.

Not in the scenario I described above, you can't. Look at this example:-

class A
{
    protected string astring = "hello world";
}

class B : A
{
    public static B FromA(A ainstance)
    {
        string testing = ainstance.astring; // <-- Can't do this
    }
}

using System.Beer;

Guffa7-Apr-06 6:38

7-Apr-06 6:38

Oh, yes, that's right. The problem with accessing the protected property is that you are trying to access a propery of a different object.

You can get around this by sending the instance of the base class to a constructor of the base class. The base class can access the protected (or even private) properties of other objects of the same class:

class A {
	protected string astring = "hello world";
	public A(A ainstance) {
		this.astring = ainstance.astring;
	}
}

class B : A {
	public B(A ainstance) : base(ainstance) {
	}
}

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