Re: regular expressions - C# Discussion Boards

19-Oct-02 12:26

Hello guys,

I have been only a few hours on C# and I am loving it.

I have created a program that downloads a web page, and i am trying to extract the keywords meta tag. I tried using the MSHTML stuff, but it was sooo slow! I figured that I will parse the meta keyword thing myself, thats when i discovered "regular expressions".

I have managed to the keywords from this kind of string:

However, the same pattern will not work on

(content and name are switched).

How cuold i make my query not care where CONTENT and NAME are located, as long as they ARE present in the string?

As usual,
Thanks in advance
Jeremy.

Jeremy Pullicino
Professional C++ Developer

Done any hacking lately?

Paul Riley19-Oct-02 13:06

Paul Riley

19-Oct-02 13:06

Use some combination along the lines of
((?<key>\w+)\s*=\s*(?<value>\w+)\s+)*
to pick up all the tags in a metatag into a GroupCollection, then find the one with CONTENT in the key field.

Disclaimer: I'm just playing with Regular Expressions myself and I could have this completely wrong, but I think it's good.

Paul
Why don't you take a good look at yourself and describe what you see - Led Zeppelin, Misty Mountain Hop

James T. Johnson19-Oct-02 13:14

James T. Johnson

19-Oct-02 13:14

Jeremy Pullicino wrote:
I have been only a few hours on C# and I am loving it.

Glad to hear that Smile | :)

Jeremy Pullicino wrote:
How cuold i make my query not care where CONTENT and NAME are located, as long as they ARE present in the string?

I'm by no means a regex guru, but this one does the trick for me though it could probably be optimized.

<meta (name=\"(?<name>.*?)\" content=\"(?<content>.*?)\")|(content=\"(?<content>.*?)\" name=\"(?<name>.*?)\")>

Using the IgnoreCase and ExplicitCapture options that works on your example above.

Regular Expression Workbench (V1.03)[^] written by Eric Gunnerson is a good tool for testing regex's because of the tooltip help breaking down what the regex does Smile | :)

HTH,

James
Sig code stolen from David Wulff

James T. Johnson19-Oct-02 13:17

James T. Johnson

19-Oct-02 13:17

I forgot to point out that mine is very picky; so a cross between my solution and Paul's would probably be best Wink | ;)

James
Sig code stolen from David Wulff

Paul Riley19-Oct-02 13:35

Paul Riley

19-Oct-02 13:35

James T. Johnson wrote:
a cross between my solution and Paul's would probably be best

I was about to say that Big Grin | :-D

Paul
Why don't you take a good look at yourself and describe what you see - Led Zeppelin, Misty Mountain Hop

Jeremy Pullicino19-Oct-02 13:41

19-Oct-02 13:41

I did a mix between paul's and mine Smile | :)

and it worked like a charm Smile | :)

Thanks guys.

My next step is to get this into an array or something (I need to store it in a database)

"word1,word2,word3 and four,word5"

Will regular expressions work well for this, or is it better if I use conventional string parsing?

Jeremy.

Jeremy Pullicino
Professional C++ Developer

Done any hacking lately?

James T. Johnson19-Oct-02 13:55

James T. Johnson

19-Oct-02 13:55

I think string parsing would be better for that. Use the Split method of the string class to get the initial array, then do parsing on each item to see if it contains more keywords (like 3 and 4 above).

James
Sig code stolen from David Wulff

Paul Riley20-Oct-02 1:36

Paul Riley

20-Oct-02 1:36

If it's always going to look like that ("word1,word2,word3 and four,word5") then use String.Split on "," because it's a LOT more efficient.

If there's randomly spaces (like "word1, word2 , word3 and four,word5") then use Regex.Split on "\s*,\s*".

Paul
Why don't you take a good look at yourself and describe what you see - Led Zeppelin, Misty Mountain Hop

Equivalent Win32 API to Control.InvokePaint?

Eric Gunnerson (msft)22-Oct-02 11:43

Eric Gunnerson (msft)

22-Oct-02 11:43

The easiest thing is probably to write two separate regular expressions, and see if either of them match.

For using regex, you might want to download my utility:

http://www.gotdotnet.com/userarea/keywordsrch.aspx?keyword=regular%20expression%20workbench

Li-kai Liu (Angus)19-Oct-02 11:37

Li-kai Liu (Angus)

19-Oct-02 11:37

Hi,

Does anyone know the equivalent APIs or mechanisms of doing
InvokePaint or InvokePaintBackground in Controls?

I want to tell a parent control to redraw itself inside the
control's client area, so it looks like a control can be
have "transparent" background (of course, not real transparent).

However InvokePaint is a protected method. There is no chance for
me to use these methods if I'm not inheriting the control class.

Thanks Smile | :)

Li-kai Liu

Re: Equivalent Win32 API to Control.InvokePaint?

David Stone19-Oct-02 12:12

David Stone

19-Oct-02 12:12

Ummm. If you are writing a control, you should be inheriting from the control class. Thus, you should have the ability to call the InvokePaint method.

Some more specifics might be nice if we're going to solve your problems. Smile | :)

Norm Almond: I seen some GUI's in my life but WTF is this mess
Leppie: I made an app for my sister and she wouldnt use it till it was colorful enough
Norm:good point leppie, from that statement I can only deduce that this GUI must be aimed at children
Leppie:My sister is 25
-Norm on the MailMagic GUI

Re: Equivalent Win32 API to Control.InvokePaint?

Li-kai Liu (Angus)19-Oct-02 13:22

Li-kai Liu (Angus)

19-Oct-02 13:22

That's what I don't want it to be at the moment... Cry | :((

I know I have to inherit the control class in order to
use it (because it's protected method...)

Currently, I'm writing many custom controls that each of
them requires this functionality. Therefore, I think
it's a good idea to "extract" this method as an external
one so that every control I've written could use it by
calling this external function, something like:

public static void DrawParentBackground(Graphic g, Control parent, Control callerControl)

No inheritance is involved in order to use these protected method...

Thanks again Smile | :)

Re: Equivalent Win32 API to Control.InvokePaint?

Li-kai Liu (Angus)19-Oct-02 14:31

Li-kai Liu (Angus)

19-Oct-02 14:31

Well, maybe still not very clear in my previous reply.

I included a picture of the button control I've been
writing for fun.

http://www.ykliu.com/problem.png[^]

It's a small button that draw everything from scratch. I plan a
few features for this button:
- support theme automatically. done! (Thanks for help from James T. Johnson)
- support shadowed text. done! (Thanks for great tutorials from Christian Graus)
- to able to draw underlying control, so it looks like transparent background is supported.

Well, that's why I come up with this question.

Though, I am able to use InvokePaint, InvokePaintBackground to redraw the
underlying parent control. Suddenly this question comes to my mind. If
I want to write another custom control that use this feature by using
InvokePaint. There is no way but inheriting it from Control Class.

Wouldn't it be better if I can write a static function, passing the caller
control and caller's parent control as parameter, then the function will
repaint caller control with the underlying parent's background.

Thanks in advance...

P.S. there's also another painting problem I found. illustrated in the included image.

Li-kai Liu

SendInput C# example

Bog19-Oct-02 8:58

19-Oct-02 8:58

Can anyone show an example of using the Win32 SendInput function in C#? It seems to be missing from dotnet and I need to send a keyboard event,

thanks

"Outside of a dog, a book is Man’s best friend. And inside of a dog, it’s too dark to read."
-Groucho Marx

Stephane Rodriguez.19-Oct-02 9:34

Stephane Rodriguez.

19-Oct-02 9:34

Google!

link[^]

How low can you go ?
(MS retrofuck)

Bog20-Oct-02 13:29

20-Oct-02 13:29

I saw that google link, and I've been working on it, but I still can't get it to work. I've reached the point where it neither throws errors, nor works.

My definitions are like this:

<br />
[System.Runtime.InteropServices.DllImportAttribute("user32.dll")]<br />
private static extern uint SendInput(<br />
	uint nInputs,     // count of input events<br />
	INPUT[] pInputs,  // array of input events<br />
	int cbSize        // size of structure<br />
);<br />
<br />
public struct INPUT {<br />
  public int type;<br />
  public short wVk;<br />
  public short wScan;<br />
  public int dwFlags;<br />
  public int time;<br />
  public UIntPtr dwExtraInfo;<br />
  private int _pad0, _pad1;<br />
}<br />
<br />
I call it like this:<br />
<br />
INPUT[] ipar=new INPUT[1];<br />
INPUT m=new INPUT();<br />
ipar[0]=m;<br />
m.type= 1; //this is INPUT_KEYBOARD<br />
m.wVk= 0x41;  //this is VK_A<br />
m.wScan= 0; <br />
m.dwFlags=0;<br />
m.time=0;<br />
uint u=0;<br />
m.dwExtraInfo=(System.UIntPtr)u;<br />
tbx.Focus(); //tbx is a TextBox I created. <br />
uint ui=SendInput(1,ipar,System.Runtime.InteropServices.Marshal.SizeOf(m));<br />
<br />

the result is that ui = 1. But the Textbox stays empty.

I also tried it by doing the union inside the INPUT and making structs for hardware and mouse input, and I got that to the same point, where ui=1 but the textbox stays empty. This always what happens to me with com interop I get to the point where there's no errors but doesn't work.

"Outside of a dog, a book is Man’s best friend. And inside of a dog, it’s too dark to read."
-Groucho Marx

leppie20-Oct-02 13:59

leppie

20-Oct-02 13:59

Hi
I think your txtbox is not getting the focus. I have had problems before. You mite need to invoke the Focus method.

Hope this helps Smile | :)

"There are no stupid question's, just stupid people."

Bog20-Oct-02 14:10

20-Oct-02 14:10

er I did invoke the Focus method, take another look at the code. Also, I know it's focused because i can see the cursor blinking in it, and the border etc..

"Outside of a dog, a book is Man’s best friend. And inside of a dog, it’s too dark to read."
-Groucho Marx

leppie20-Oct-02 14:24

leppie

20-Oct-02 14:24

Bog wrote:
er I did invoke the Focus method, take another look at the code.

tbx.Focus(); only calls the function.

You will need to do something like this I suspect.

if (tbx.InvokeRequired) tbx.Invoke(tbx.Focus);
else tbx.Focus();

Also I see that there is no KEYEVENTF_KEYUP for the SendInput. This I presume you will need to do after the first SendInput you are sending.

"There are no stupid question's, just stupid people."

Bog20-Oct-02 14:51

20-Oct-02 14:51

I tried a Console.WriteLine(tbx.InvokeRequired) and it was false. Also, I know the textbox is getting focus because I can see it. The curosor is blinking in the textbox, and when I type text goes into it.

I don't think sending a KEYUP is required, because it's not required in normal keyboard activity either. For example, when you press a key here in a web form, the letter appears on keydown, not on keyup. Also, I've seen examples of this in C++ (non dotnet) and non of the examples have a subsequent KEYUP.

Thanks for your responses anyway tho.

"Outside of a dog, a book is Man’s best friend. And inside of a dog, it’s too dark to read."
-Groucho Marx

parsing HTML

Jeremy Pullicino19-Oct-02 8:07

19-Oct-02 8:07

Hello,

i am very new to c#.

i made a program to download a web page.

Now I want to parse out the meta keyword tags:
Done any hacking lately?

Re: parsing HTML

Stephane Rodriguez.19-Oct-02 9:28

Stephane Rodriguez.

19-Oct-02 9:28

Add the Microsoft.mshtml namespace (add a reference to this primary assembly that you'll find in the program files \ .NET folder).
Then the IHTMLMetaElement interface is the right stuff for you.

How low can you go ?
(MS retrofuck)

Re: parsing HTML

Jeremy Pullicino19-Oct-02 12:41