Re: Saving Bitmap in HashTable - C# Discussion Boards

Re: Shifting from .net 2.0 to .net 3.0

20-Feb-08 21:12

Is it a must thatg for using .net 3.0 we shld use MS VS 2008

Gareth H21-Feb-08 0:44

Gareth H

21-Feb-08 0:44

thenewbee,

No, you can use VS05 but like i said, if you're using different versions of the framework, its easiest to use VS08.

Regards,
Gareth.

Saving Bitmap in HashTable

vivekphlp18-Feb-08 23:53

vivekphlp

18-Feb-08 23:53

Iam new to C#. . . Here is my my requirement . .
I want to save some images into a Hashtable & retrieve it later. . .
How can it be done.. .
Plz help

Proud To Be an Indian

free_soul42419-Feb-08 0:12

free_soul424

19-Feb-08 0:12

Use the following code, i think it will work...

public partial class Form1 : Form
{
Hashtable imgHash = new Hashtable();
public Form1()
{
InitializeComponent();
/* create new bitmap*/
Bitmap bmp = new Bitmap(100, 100);
Rectangle rect = new Rectangle(12, 12, 50, 50);
Graphics g = Graphics.FromImage(bmp);
g.DrawRectangle(new Pen(Color.Red), rect);

/* put the bitmap in hashtable*/
imgHash.Add("1", bmp);
}

private void Form1_Paint(object sender, PaintEventArgs e)
{
if(imgHash != null)
this.CreateGraphics().DrawImage((Image)imgHash["1"] ,new Point (0,0));
}
}

Martin#19-Feb-08 0:33

19-Feb-08 0:33

Hello,

faheem424 wrote:
this.CreateGraphics().

Why would you want todo that?

"e.Graphics" is the wright solution.´

faheem424 wrote:
imgHash["1"]

Wouldn't do that without a "Hashtable.Contains" check before.

All the best,

Martin

free_soul42419-Feb-08 0:39

free_soul424

19-Feb-08 0:39

yup you may change the condition with the following code

if (imgHash.Contains("1"))
e.Graphics.DrawImage((Image)imgHash["1"], new Point(0, 0));

thenewbee19-Feb-08 19:27

19-Feb-08 19:27

Thanks a lot . .
can i save that image back to a Bitmap
eg:
bmp = imgHash["1"];
hope it wil work.. .

Martin#20-Feb-08 20:21

20-Feb-08 20:21

Hello,

As the Hashtable holds the Bitmap instance as an object, you will get an compiletime error telling you that an implicit conversion from object to Bitmap is not possible!
Therefor you would have to do the casting yourselfe.
If you are 100% sure that the Hashtable only holds Bitmaps:

if(ht.Contains("1"))
{
    Bitmap bmp2 = (Bitmap)ht["1"];
}
 
or:
 
Bitmap bmp2 = obmp as Bitmap;
if(bmp2!=null)
{
 				
}

All the best,

Martin

thenewbee20-Feb-08 21:02

20-Feb-08 21:02

Thanks Again . Smile | :)

Is there any diff in creating obj using

Bitmap bmp2 = new Bitmap();
&
Bitmap bmp2 = obmp as Bitmap;

What is this obmp???

Martin#21-Feb-08 2:45

21-Feb-08 2:45

Hello,

thenewbee wrote:
What is this obmp???

Sorry, forgot that:
object obmp = ht["1"]; //just gets the Bitmap as an object out of the Hashtable.

thenewbee wrote:
Is there any diff in creating obj using

Bitmap bmp2 = new Bitmap();
&
Bitmap bmp2 = obmp as Bitmap;

"new Bitmap" instanciates a Bitmap object, which was not there before.

"as Bitmap" tries to convert an existing object to a Bitmap (which was instanciated before).
"as" will never throw an exception, therefor I often use it instead of a cast like "(Bitmap)object".

All the best,

Martin

thenewbee21-Feb-08 3:16

Opening Internet Shortcut in default browser from C# [modified]

21-Feb-08 3:16

Thanks Martin . . ..
Smile | :)

__DanC__18-Feb-08 23:48

Re: Opening Internet Shortcut in default browser from C#

18-Feb-08 23:48

I have a .url file which I want to launch in the default browser from C#, the problem I have is that if I double-click in Windows it opens as expected but if I launch using Process.Start() with or without UseShellExecute it launches and opens a print dialog to print the web page! Any ideas what could be wrong?

<br />
Process proc = new Process();<br />
proc.StartInfo = new ProcessStartInfo("C:\Path\To\Link.url", "");<br />
proc.StartInfo.UseShellExecute = true; // Makes no difference if set to false<br />
proc.Start();<br />

modified on Tuesday, February 19, 2008 6:09 AM

Mircea Puiu19-Feb-08 1:58

Re: Opening Internet Shortcut in default browser from C#

19-Feb-08 1:58

Assuming yo have test.html in C:\
then Process.Start("C://test.html") will do the trick Smile | :)

SkyWalker

__DanC__19-Feb-08 2:45

Re: Opening Internet Shortcut in default browser from C#

19-Feb-08 2:45

Thanks but the problem is not html files. The problem I am having is with .URL files (Internet shortcuts), they do not open correctly with any of the above methods.

Mircea Puiu19-Feb-08 3:18

Re: Opening Internet Shortcut in default browser from C#

19-Feb-08 3:18

Oh sorry, I misunderstood you!
Use the following:

using System.IO;
using System.Text.RegularExpressions;

string lnk = File.ReadAllText("C:\\...your full path to the url file....");
Match m = Regex.Match(lnk, "BASEURL=.+\r\n", RegexOptions.IgnoreCase);
Process.Start("IExplore.exe", m.Value.ToUpper().Replace("BASEURL=", ""));

SkyWalker

__DanC__19-Feb-08 4:59

Re: Opening Internet Shortcut in default browser from C#

19-Feb-08 4:59

Thanks for the idea but I would really like to know why it opens a print dialog and not the URL file as this mechanism will be used to open all types of file, not just URL files. What should be the correct method for launching a .URL file from C#?

Mircea Puiu19-Feb-08 5:08

Re: Opening Internet Shortcut in default browser from C#

19-Feb-08 5:08

That's the way it does the job (it was designed to do so).
You have to select Open to open the resource (if the browser "knows" how to open it)

SkyWalker

__DanC__19-Feb-08 5:12

Re: how to block website [modified]

19-Feb-08 5:12

What I mean is if I double-click on a .URL file in Windows or I type the name of one in the command prompt it opens the link in the correct browser as expected so why would opening the file as I am open a print dialog, there must be a reason for it which is what I would like to get to the bottom of. It is not feasible to have a different method of launching each file type, especially when Windows explorer launches the file as expected.

how to block website

Tahir Abbasi18-Feb-08 23:39

Tahir Abbasi

18-Feb-08 23:39

hi to all!
i want to block some website in c# . My question is that how i can block specifc urls using C# application .can anyboy tell me how i can do this. if there exist any link that contains information about this.
thanks 2 all!

Tahir

Mircea Puiu19-Feb-08 1:32

19-Feb-08 1:32

I do not know if I understand what you exactly want, but here are some lines for the configuration file:

<location path="......" />  
	<authorization>    
		<allow users="......" />    
		<deny users="*" />  
	</authorization>
</location>

... and more on asp.net security at http://www.microsoft.com/mspress/books/sampchap/6501.aspx

modified on Tuesday, February 19, 2008 7:45 AM

Re: how to block website

Tahir Abbasi19-Feb-08 3:37

Tahir Abbasi

19-Feb-08 3:37

thank u Mircea Puiu .
But i m not developing web Application . I m developing a website blocker that will block some specifci urls , its a desk top application . I u have any idae about this then reply me.
thanks alot

Tahir

Re: how to block website

Mircea Puiu19-Feb-08 3:53

Re: this.MaximumSize issue

19-Feb-08 3:53

Maybe the Browser Helper Objects are what you are looking for.
Have a look here[^].
It's C++, but it should not be a problem Smile | :)

(PS: if it is one Smile | :)

, then use this[^])

SkyWalker

this.MaximumSize issue

Harvey Saayman18-Feb-08 23:09

Harvey Saayman

18-Feb-08 23:09

Hey ppl

im having problems setting a forms this.MaximumSize at runtime. The property only gets, so its read only... any ideas?

thanx

Harvey Saayman - South Africa
Junior Developer
.Net, C#, SQL
think BIG and kick ASS

you.suck = (you.passion != Programming)

Martin#18-Feb-08 23:15