textbox control - C# Discussion Boards

Vodstok13-Dec-05 5:46

13-Dec-05 5:46

I have been scouring Google for hours on this and can't find anything useful.

I have been wonmdering if there is a way to assign a transparent color (like Color.Transparent) for web graphics, basically a nice little class that would return a true transparent color, rather than having to run the entire image through a class to set a particular color transparent.

Or, barring that, a nice clean chunk of C# code that can be used to set the transparency to a particular color. 98% of what I have seen has so much garbage code in it it is hard to discern where the actual transparency code resides.

I would usually sit and hammer the hell out of messier code that I have managed to find, but I dont really have time to sit and play with it (which is a real shame. I love playing with image code)

Any ideas?

______________________
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Re: Transparent Color in Asp .Net C#

Guffa13-Dec-05 7:27

Guffa

13-Dec-05 7:27

In what way should this be specific for web graphics?

Color.Transparent is a transparent color, why can't you use that?

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Re: Transparent Color in Asp .Net C#

Vodstok13-Dec-05 7:30

Vodstok

13-Dec-05 7:30

When creating a Dynamic web image, for some reason, the browser does not actually render Color.Transparent as transparent. it usually seems to set it to black, which can be a problem.

I think it is because it handles the images by default as Bitmaps, rather than a gif (even though that has been specified) and the bitmap format doesnt support transparency (at least in .net)

______________________
Mr Griffin, eleventy billion is not a number... WTF | :WTF:

Re: Transparent Color in Asp .Net C#

Guffa13-Dec-05 13:08

Guffa

13-Dec-05 13:08

Are you really sure that it handles the image as bitmap? Bitmap images are windows specific and uncompressed, so they are very impractical for web purposes.

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Re: Transparent Color in Asp .Net C#

Vodstok14-Dec-05 1:48

Vodstok

14-Dec-05 1:48

here is an example of the code for a pretty simple image:

                  Response.ContentType = "image/gif";<br />
<br />
			Bitmap bm = new Bitmap(300,300);<br />
			Graphics gp = Graphics.FromImage(bm);<br />
<br />
			Rectangle re = new Rectangle(0,0,300,300);<br />
			SolidBrush br = new SolidBrush(Color.FromArgb(255,0,0,0));<br />
<br />
			gp.FillRectangle(br,re);<br />
<br />
			<br />
<br />
			SolidBrush br2 = new SolidBrush(Color.Tomato);<br />
			gp.FillEllipse(br2,75,75,150,150);<br />
<br />
			gp.SmoothingMode = SmoothingMode.HighQuality;<br />
			bm.MakeTransparent(Color.FromArgb(255,0,0,0));<br />
			bm.Save(Response.OutputStream, ImageFormat.Gif);<br />
			gp.Dispose();<br />
			bm.Dispose();

this sits in the Page_Load of an aspx page. Notice that the object that is created and output is fundamentally a bitmap (which isnt actually windows specific), but is then output in gif format.

Color.Transparent works just fine for windows forms (win32 apps), but not so great for web graphics.

I have played with some classes others have created for making transparent gifs, but so far they are either terribly messy or hit-or-miss.

______________________
Mr Griffin, eleventy billion is not a number... WTF | :WTF:

Re: Transparent Color in Asp .Net C#

Guffa18-Dec-05 1:26

Guffa

18-Dec-05 1:26

Have a look at this[^].

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Re: Transparent Color in Asp .Net C#

Vodstok19-Dec-05 1:56

Vodstok

19-Dec-05 1:56

Awesome. I just modified it a little to work with my code, and it did. Thank you Smile | :)

how did you find that?

______________________
Mr Griffin, eleventy billion is not a number... WTF | :WTF:

textbox control

John L. DeVito13-Dec-05 5:09

John L. DeVito

13-Dec-05 5:09

Heyas all,

I have project that has a mainform and on it is a read-only textbox control. I have another source file that hold a class I made myself. I'm trying to access the textbox control that is on the mainform from my class file, and I keep getting erros that it's inacceble. The code wizard automatically creates the control as private. I have a method in my class that simply does this:

void vWriteToTextbox(void)<br />
{<br />
   // write to textbox on mainform I'm trying somsthing like...<br />
   // MainForm.textbox1.Text = "Hello";<br />
}<br />

and like I said it's not working. How can I access the control from my file (which of course is in the same project)?

Thanks,
John

Re: textbox control

User 665813-Dec-05 5:29

User 6658

13-Dec-05 5:29

John L. DeVito wrote:
How can I access the control from my file

Why would you want to do this?

You can either make the control varialbe "textbox1" public, or create a get-function (or property) to return the textbox variable like this:

public TextBox box { get { return textbox1; } }

You also need to have a reference to your main form, you can't just do MainForm.something unless something is declared static

regards

modified 12-Sep-18 21:01pm.

Re: textbox control

Curtis Schlak.13-Dec-05 5:34

Curtis Schlak.

13-Dec-05 5:34

Okay, the easy way to fix this is select the TextBox in the form designer and change the value of the Design >> Modifiers property to public.

While that's the easy way, it breaks the encapsulation principle of OOD. May I suggest creating a property in your main form that exposes the value of the TextBox?

For example, in your main form's class declaration, provide the following declaration.

public string MyInterestingTextBoxValue
{
  set
  {
    this.textBox1.Text = value;
  }
}

Then, you can change your method above to

private void vWriteToTextbox()
{
  // Write to textbox on main form
  MainForm.MyInterestingTextBoxValue = "Hello";
}

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: textbox control

John L. DeVito13-Dec-05 16:38

John L. DeVito

13-Dec-05 16:38

Thanks Curtis I like the idea of wrapping it in a property. I know I could have changed the access identifier but I really REALLY didn't want to do that. Appreciate the time, works great. Thanks again. Smile | :)

Thanks,
John

Re: textbox control

Curtis Schlak.14-Dec-05 4:34

Curtis Schlak.

14-Dec-05 4:34

John, my pleasure. Hope all turns out well. Happy coding!

"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty

Re: textbox control

John L. DeVito15-Dec-05 15:16

John L. DeVito

15-Dec-05 15:16

Heyas Curtis,

I've actually come across a bit of a problem, VS is saying that in order for me to set this property value I must have an instantiated object. I don't understand that. the MainForm is going to be instantied when it runs. Here's my code:

In MainForms Class description I have...

<br />
  internal String txtStatusValue{ set{ this.txtStatus.Text = value;}}<br />

and then in my class file I have..

<br />
  internal void vMyFunction()<br />
        {<br />
            MainForm.txtStatusValue = "Blah Blah Blah";<br />
        }<br />

I don't get it, could I trouble you for but more assistance?

Thanks,
John

Re: textbox control

TheGreatAndPowerfulOz15-Dec-05 16:49

TheGreatAndPowerfulOz

15-Dec-05 16:49

sounds like your calling the txtStatusValue before the mainform is instantiated or before the variable you're using to call the mainform propery is initialized.

do something like this:

public class MainForm: Form
{
   public static MainForm myMainForm = null;

   public MainForm()
   {
      myMainForm = this; // first line of code in ctor (before InitializeComponent() and before other objects get ctor'd
   }

   internal public string txtStatusValue { set { txtStatus.Text = value; } }
}

public MyClass
{
   public void someFunc()
   {
      MainForm.myMainForm.txtStatusValue = "foo";
   }
}

hope this helps...

How to pass array of string or doubles between C# and Managed C++

devinzhang13-Dec-05 5:04

devinzhang

13-Dec-05 5:04

If I have a function in dll generated by managed C++, how do I pass arrays in C# so that I can get my output array back?

Any help is appreciated!

Devin

Re: How to pass array of string or doubles between C# and Managed C++

Koushik Biswas13-Dec-05 9:47

Koushik Biswas

13-Dec-05 9:47

What do you mean? Your question keeps many details unsaid. If you have a C++.NET DLL with a function like

void YourClass::MyFunc( double [] dArray ){...}

Why can't you call that function from C# directly like

...<br />
double [] dArray = new double [ 10 ];<br />
YourClass yc = new YourClass();<br />
yc.MyFunc( dArray );<br />
...

If your question is more complex than that, you will get better responses if you elaborate...

Koushik Biswas

Re: How to pass array of string or doubles between C# and Managed C++

devinzhang13-Dec-05 14:42

devinzhang

13-Dec-05 14:42

Thanks Koushik!

It is then pretty natural.

Devin

How to get message from Queue?

Rashid.Mahmood13-Dec-05 4:32

Rashid.Mahmood

13-Dec-05 4:32

Hi all,
I have developed a dll in Win32. That dll finds the updated regions
of the desktop and then post these regions data to a C# application
using PostThreadMessage(). But problem is here i m not so much use to
with C# so i havent any idea how can i get it from the Application
message queue of my C# application.

Thanx

Re: How to get message from Queue?

Judah Gabriel Himango13-Dec-05 4:39

Judah Gabriel Himango

13-Dec-05 4:39

In C#, you typically don't deal with the Win32 message queue. The .NET framework is designed to abstract away the underlying operating system & hardware. So, if you're listening for when a user moves his mouse over your System.Windows.Forms.Form, just setup an event handler for the MouseMove event.

Form myForm = new Form();
myForm.MouseMove += new MouseEventHandler(MyMouseMoveFunction);
...
void MyMouseMoveFunction(object sender, MouseEventArgs arguments)
{
}

That said, if you want to get low level, past the abstractions, you can create a class that inherits from System.Windows.Forms.Form, then override the WndProc virtual method; that method is called every time your form receives a windows message.

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Bought a House!
Judah Himango

[Message Deleted]

Judah Gabriel Himango13-Dec-05 4:39

Judah Gabriel Himango

13-Dec-05 4:39

[Message Deleted]

Re: How to get message from Queue?

Rashid.Mahmood13-Dec-05 18:33

Rashid.Mahmood

13-Dec-05 18:33

Dear u r quite right that i can track mouse movements. But here is the
different case my dll is a hooking dll and is responsible for getting
screen display updates. So here i m restricted to use that unmanaged
dll.

I have passed dll the managed thread id so that dll can post messages
of screen updates to my C# application.
Is it right to pass a managed thread id in PostThreadMessage()?

Thanx for ur response.

WebBrowser and Console Applications

S. Senthil Kumar13-Dec-05 4:32

S. Senthil Kumar

13-Dec-05 4:32

Does the WebBrowser control introduced in .NET 2.0 work fine with console applications? I'm facing problems doing something like

string x = "<HTML>abc</HTML>";
browser.DocumentText = x;

Unfortunately, x never gets set, browser.DocumentText always remains as <HTML> </HTML>

On a hunch, I tried doing an Application.DoEvents right after setting the DocumentText property and it worked. Does that mean there is no *easy* way to use the WebBrowser just for inspecting and manipulating the DOM tree?

Regards
Senthil
_____________________________
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Re: WebBrowser and Console Applications

Judah Gabriel Himango13-Dec-05 4:43

Judah Gabriel Himango

13-Dec-05 4:43

We've had trouble with WebBrowser controls without a parent; you may end up having to create an invisible form and add the browser to that form before you can do things with the document.

Re: WebBrowser and Console Applications

S. Senthil Kumar15-Dec-05 5:01

S. Senthil Kumar

15-Dec-05 5:01

That did the trick, thank you. I dearly wish .NET 2.0 provided a class to do nothing else but parse HTML.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: WebBrowser and Console Applications

Judah Gabriel Himango15-Dec-05 5:22

Judah Gabriel Himango

15-Dec-05 5:22

S. Senthil Kumar wrote:
I dearly wish .NET 2.0 provided a class to do nothing else but parse HTML.

I agree.

Tech, life, family, faith: Give me a visit.
I'm currently blogging about: Bought a House!
Judah Himango

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