Creating a Bitmap from IntPtr to unmanaged memory: issues [modified] - C# Discussion Boards

Re: How to get a pop-up window in c#.net and pass values to it from DataList parameters

Elina Blank15-Jun-06 4:01

15-Jun-06 4:01

Can you open the window through normal Javascript, and put the values for title and price in Session.

Sincerely,
Elina

Life is great!!!
Enjoy every moment of it! Blush | :O

Re: How to get a pop-up window in c#.net and pass values to it from DataList parameters

tedhill1315-Jun-06 4:21

tedhill13

15-Jun-06 4:21

Hi Elina. Good to know people who loves life. Yes, life is wonderful ! Big Grin | :-D

Could you tell me, using some code example, how to put values in the Session from a DataList and how to retrieve them inside a pop-up window ?

Re: How to get a pop-up window in c#.net and pass values to it from DataList parameters

Elina Blank15-Jun-06 4:25

Elina Blank

15-Jun-06 4:25

Hi tedhill,
(Should I add the number ? )

Here is how you put the value to the Session:
Session[indexName] = yourValue;

Now retrieve it:
yourRetrievedValue= (YourValueType)Session[indexname].

indexName is any string you choose.

Good Luck,
Elina

Life is great!!!
Enjoy every moment of it! Blush | :O

Re: How to get a pop-up window in c#.net and pass values to it from DataList parameters

tedhill1315-Jun-06 5:03

tedhill13

15-Jun-06 5:03

Thank you, Elina.

I will try it !

Re: How to get a pop-up window in c#.net and pass values to it from DataList parameters

Elina Blank15-Jun-06 5:12

Elina Blank

15-Jun-06 5:12

Good luck,

Let me know, if you will have problems.
Will be happy to help, if I will be able, of course Smile | :)

Sincerely,
Elina

Life is great!!!
Enjoy every moment of it! Blush | :O

drawing on tab control

donkaiser15-Jun-06 3:26

donkaiser

15-Jun-06 3:26

I drew some shape that i would like it to appear on the top of the tab control. Right it's just draw on to the form "behind" the tab. how should i do that?

thanks

Donkaiser

Re: drawing on tab control

donkaiser15-Jun-06 4:29

donkaiser

15-Jun-06 4:29

solved by using paint event of the tab.

Donkaiser

Creating a Bitmap from IntPtr to unmanaged memory: issues [modified]

Jon Hulatt15-Jun-06 3:06

Jon Hulatt

15-Jun-06 3:06

Hi all,

I'm trying to do some managed directshow stuff and i'm a bit stuck on some Bitmap things.

I'm trying to make a Bitmap in a callback where I am presented with an IntPtr to a block of unmanaged memory which contains my pixel data.

I can create the bitmap just fine with one of the Bitmap constructor overloads:-

Bitmap b = new Bitmap(
                720, 
                576, 
                -2160, 
                PixelFormat.Format24bppRgb,
                (IntPtr)(ip.ToInt32() + 1244160 - 2160)
                );

(stride and the IntPtr itself are hacked around a bit because my pixel data scans left-right,bottom-top. but that's not important right now).

When i've done this, I can create and use the bitmap. However, the Bitmap does not copy the data, and as such when I free the memory for the bitmap data (I have to do this - this is unsafe code), the bitmap is corrupt.

Edit: i've also tried the Bitmap.Clone() method- but the new bitmap still references the unmanaged data.

So, i've been looking for a way of copying the pixel data into a managed type so that i can keep a reference to it for as long as I need it, and then let the GC free it. But i'm struggling on how to do this.

I can easily copy the data to a byte[] array (with Marshal.Copy), but then how can I create a bitmap from the byte array?

Or can anyone else see an alternative way of doing this?

thanks

Jon

using System.Beer;

-- modified at 9:18 Thursday 15th June, 2006

Re: Creating a Bitmap from IntPtr to unmanaged memory: issues

Guffa15-Jun-06 3:27

Guffa

15-Jun-06 3:27

If you create a new blank Bitmap, you can use LockBits to pin the bitmap data and get a pointer to it. Could you use that with Marshal.Copy to copy the unmanaged data into the bitmap?

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b { font-weight: normal; }

Re: Creating a Bitmap from IntPtr to unmanaged memory: issues

Florian Storck26-Jun-06 4:50

Florian Storck

26-Jun-06 4:50

Guffa wrote:
If you create a new blank Bitmap, you can use LockBits to pin the bitmap data and get a pointer to it. Could you use that with Marshal.Copy to copy the unmanaged data into the bitmap?

Ups, seems that my reply notification didn't worked...

Meanwhile it seems to work using an IntPtr for initialising, but as far as I can see, the new instance allocates also memory, which is completetly unnecessary because the bitmap data are already in an unmanaged buffer, where the IntPtr points to. My initial idea was to avoid any copying issues for performance reasons and just define the bitmap format and set the pointer directly to the image data. This seems to be a lot more complicated used the managed environment. I'm not sure if it would work if the IntPtr would point to a managed location.

Any suggestions are welcome.

Bye,
Florian

Checkbox Column in DataGridView

paas15-Jun-06 2:30

paas

15-Jun-06 2:30

I am developing some applications with VS 2005. In a datagridview I have added a checkbox column which, at times, I would like to be able to programatically check or uncheck. Unfortunately, whether I have that column bound to a data source or not I can not seem to programatically check or uncheck the column by changing the value to True or False (TrueValue is set to True, FalseValue is set to False). If I bind the column to a datasource that is False, the column shows as unchecked, and then I can not programatically check it and vice versa. Physically checking or unchecking via mouse clicks works fine. Can anyone tell me what I must do to programatically check or uncheck a bound or unbound checkbox column in a datagridview?

Thank you.

Re: Checkbox Column in DataGridView

paas15-Jun-06 3:41

paas

15-Jun-06 3:41

Update to my question. I figured out that if I move to another column in the grid, after programatically updating the grid, the check-box does change as I expected. For some reason it does not change immediately. Still very peculiar and I'm beginning to think it may be related to an override of ProcessCmdKey that I have in this application.

How to get Page Title using WebBrowser control

VenkataRamana.Gali15-Jun-06 0:57

VenkataRamana.Gali

15-Jun-06 0:57

Hello all,

In my Winform i am using webBrowser control. in this i am displaying the asp.net page. it is working fine.
but I want to get the Page Title using webBrowser control. How to get this?

any sounds

regards
GV Ramana

regards
GV Ramana

Re: How to get Page Title using WebBrowser control

Alexander Wiseman15-Jun-06 5:36

Alexander Wiseman

15-Jun-06 5:36

Hello,

I'm not sure if you're using the new WebBrowser control class in .NET 2.0 or whether you are using AxWebBrowser with .NET earlier than 2.0. I'll give what I think is the solution for both of these:

For the WebBrowser class in .NET 2.0:

WebBrowser myBrowser;
...
// After you load your page, access the <code>Document</code> property of the control:
HtmlDocument myDocument = myBrowser.Document;

// Now the HtmlDocument class has a property called "Title"; use it to retrive the document title:
String myTitle = myDocument.Title;

This code in .NET 2.0 will get the value contained between the HTML tags <title> and .

AxWebBrowser control in .NET earlier than 2.0

AxSHDocVw.AxWebBrowser myBrowser;
...
// After you load your page, access the <code>Document</code> property of the control:
HTMLDocument myDoc = myBrowser.Document;

// Now the HTMLDocument has a property called "title"; use it to retrieve the document title:
String myTitle = myDoc.title;

This code will do the same as the code above, that is, retrieve the value between the HTML tags <title> and .

Hope that helps! Let me know if that does not solve the problem and I will try to help you as best I can.

Sincerely,
Alexander Wiseman

How to use a variable declared in one from to other form?

praveenqwe15-Jun-06 0:34

praveenqwe

15-Jun-06 0:34

Hi, Everyone

i am new to c# can anyone help me how to call a variable in Form2 which is been declared in Form1 .

Thankyou.

Regards,
Praveen

Re: How to use a variable declared in one from to other form?

albCode15-Jun-06 0:53

albCode

15-Jun-06 0:53

declare public variable in from1

Re: How to use a variable declared in one from to other form?

NaNg1524115-Jun-06 0:54

NaNg15241

15-Jun-06 0:54

There are so many threads about it.
please search the forum or the articles in CP, and u can be sure to find aloooooot about it.

Re: How to use a variable declared in one from to other form?

rah_sin15-Jun-06 1:00

rah_sin

15-Jun-06 1:00

declare variable to access in form1 as public and then

on form2 u can create instance of form1 like

form1 frm1 = new form1();

and can access variable

frm1.variable

or u can pass variable from form1 to form2 by changing constructor of form2

to accept variable like

on form1 whrere u are openning form2

form2 frm2 = new form2(variable);
frm2.show();

and can recieve variable on form2 in form2's constructor like this

class form2(datatype variable)
{
variable2 = variable;
}

rahul

Re: How to use a variable declared in one from to other form?

Aijaz Ahmed Niazi15-Jun-06 1:41

Aijaz Ahmed Niazi

15-Jun-06 1:41

to call varieable that is declared in form1 u have to declare that veriable as "public static" in form1
eg: public static int myint
and then call this variable in form2
eg form1.myint

from Aijaz ahmed

How to get client ip address

Raghu Deshpande14-Jun-06 23:32

Raghu Deshpande

14-Jun-06 23:32

Hi All,

I am using HTTPHandler to process certain requests from a client machine. But whenever I try to retrieve the client ipaddress through servervariables I get my server ip address. Because client machine requests are routed through my server. Is there any other way I can get client machine IP Address?

Need help regarding this issue.

Raghu

Re: How to get client ip address [modified]

albCode14-Jun-06 23:51

albCode

14-Jun-06 23:51

string sClientIP =""<br />
sClientIP = Request.UserHostAddress();<br />
Response.Write(sClientIP);

how to attach more than 10mb file usinh html file field

ayyp14-Jun-06 23:27

ayyp

14-Jun-06 23:27

hi all,i try to attach morethan 10mb files using html file field but it wont allow it.is there any way to do this?

Regards,
ayyp

Re: how to attach more than 10mb file usinh html file field

Guffa14-Jun-06 23:52

Guffa

14-Jun-06 23:52

The default maximum size for a request is 4 MB. This can be changed using a setting in web.config. I don't remember it's name right now, though.

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b { font-weight: normal; }

Re: how to attach more than 10mb file usinh html file field

ayyp15-Jun-06 0:04

ayyp

15-Jun-06 0:04

sorry i didn't get u can u reply clearly........plz........ Smile | :)

Regards,
ayyp

Re: how to attach more than 10mb file usinh html file field

Guffa15-Jun-06 0:36

Guffa

15-Jun-06 0:36

Translation:

da deft max sz for a req is 4 mb dis can b chng uzn a setn in web.config i dont remember its nm right now, dou

Wink | ;)

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b { font-weight: normal; }

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