CType() what's the difference?

[Marcel]

Hi,

I've found some sample code to put some text into Word. I'm testing this
code to learn from it, but I can't find an explanation for the use of CType
in the following code. Can someone explain the use of CType?

app = CType(GetObject (Nothing, "Word.Applicati on"), Word.Applicatio n)
app.Selection.T ext = "Hi, this is text."

Also does:

app = GetObject(Nothi ng, "Word.Applicati on")
app.Selection.T ext = "Hi, this is text."

Both do work.

Regards,

Marcel

[Greg Burns]

The second probably wont work with Option Strict On.

Greg

"Marcel" <m.*********@ho me.nl> wrote in message
news:32******** *****@individua l.net...

Hi,

I've found some sample code to put some text into Word. I'm testing this
code to learn from it, but I can't find an explanation for the use of
CType in the following code. Can someone explain the use of CType?

app = CType(GetObject (Nothing, "Word.Applicati on"), Word.Applicatio n)
app.Selection.T ext = "Hi, this is text."

Also does:

app = GetObject(Nothi ng, "Word.Applicati on")
app.Selection.T ext = "Hi, this is text."

Both do work.

Regards,

Marcel

[Shariq Khan]

First is an early bound call to the object; compiler knows exactly what
method to call at compile and won't let you call something by mistake
including checking all parameter types and results.

Second is a late bound call probably using IDispatch interface. Even though
it works, it is bad practice to use late binding.

Stick to using proper object types whenever you can instead of calling
methods on the "object" type.


"Marcel" <m.*********@ho me.nl> wrote in message
news:32******** *****@individua l.net...

Hi,

I've found some sample code to put some text into Word. I'm testing this
code to learn from it, but I can't find an explanation for the use of
CType in the following code. Can someone explain the use of CType?

app = CType(GetObject (Nothing, "Word.Applicati on"), Word.Applicatio n)
app.Selection.T ext = "Hi, this is text."

Also does:

app = GetObject(Nothi ng, "Word.Applicati on")
app.Selection.T ext = "Hi, this is text."

Both do work.

Regards,

Marcel

[Cor Ligthert]

Marcel,

In other words than Greg and Shariq, however the same

CType and DirectCast tells what "Type" the "Object" is at compile time and
it will be set in the code.
Without that it has to be found at Runtime and therefore is your program at
runtime slower.

When you have Option Strict On in top of your program, you are not allowed
*not* to tell what object is used.

Therefore we mostly tell in these newsgroups that early binding is with
Option Strict On

As I describe it often

With Option Strict On
performance of VBNet = C#
Without
VBNet = VB6

I hope that this add something extra to the text from Greg and Shariq?

Cor

"Marcel" <m.*********@ho me.nl>

Hi,

I've found some sample code to put some text into Word. I'm testing this
code to learn from it, but I can't find an explanation for the use of
CType in the following code. Can someone explain the use of CType?

app = CType(GetObject (Nothing, "Word.Applicati on"), Word.Applicatio n)
app.Selection.T ext = "Hi, this is text."

Also does:

app = GetObject(Nothi ng, "Word.Applicati on")
app.Selection.T ext = "Hi, this is text."

Both do work.

Regards,

Marcel

[Marcel]

Greg, Shariq and Cor,

Thank you all for your replys. Now it's clear to me what to do and to
behave.

Regards,

Marcel Kollenaar

[Herfried K. Wagner [MVP]]

"Cor Ligthert" <no************ @planet.nl> schrieb:

As I describe it often

With Option Strict On
performance of VBNet = C#
Without
VBNet = VB6

The last line is wrong. You could use early binding in VB6 too, and you can
use reflection to mimic VB.NET's late binding in C#:

\\\
Dim App As Word.Applicatio n
Set App = New Word.Applicatio n
..
..
..
Call App.Quit
///

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Marcel]

Herfried,

This example hereafter is for VB6?

Marcel

"Herfried K. Wagner [MVP]" <hi************ ***@gmx.at> schreef in bericht
news:ec******** ******@TK2MSFTN GP11.phx.gbl...

"Cor Ligthert" <no************ @planet.nl> schrieb:

As I describe it often

With Option Strict On
performance of VBNet = C#
Without
VBNet = VB6

The last line is wrong. You could use early binding in VB6 too, and you
can use reflection to mimic VB.NET's late binding in C#:

\\\
Dim App As Word.Applicatio n
Set App = New Word.Applicatio n
.
.
.
Call App.Quit
///

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Herfried K. Wagner [MVP]]

"Marcel" <m.*********@ho me.nl> schrieb:

This example hereafter is for VB6?

Yes.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>

[Cor Ligthert]

>> As I describe it often

With Option Strict On
performance of VBNet = C#
Without
VBNet = VB6

The last line is wrong. You could use early binding in VB6 too, and you
can use reflection to mimic VB.NET's late binding in C#:

Did I deny something, the sample is about performance, and just something in
general?

Cor

[Herfried K. Wagner [MVP]]

"Cor Ligthert" <no************ @planet.nl> schrieb:

As I describe it often

With Option Strict On
performance of VBNet = C#
Without
VBNet = VB6

The last line is wrong. You could use early binding in VB6 too, and you
can use reflection to mimic VB.NET's late binding in C#:

Did I deny something, the sample is about performance, and just something
in general?

You saud that without 'Option Strict On' VB.NET's performance is the same as
the performance of VB6, which is simply not true.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://dotnet.mvps.org/dotnet/faqs/>