Re: Prevent Monitor Standby and ScreenSaver Activation - C# Discussion Boards

Re: Catch C++ exception in C#

led mike15-Oct-07 8:05

led mike

15-Oct-07 8:05

Not Knuth wrote:
but it is very inefficient.

Compared to what? It is currently your only known solution so it is the most efficient solution. Roll eyes | :rolleyes:

Re: Catch C++ exception in C#

Not Knuth15-Oct-07 8:15

Not Knuth

15-Oct-07 8:15

Following that logic, it is also the most inefficient solution! Roll eyes | :rolleyes:

It might turn out to be the best option. But perhaps there is another one that neither of us know. That is why I posted my question here.

Re: Catch C++ exception in C#

Liam O'Hagan15-Oct-07 20:57

Liam O'Hagan

15-Oct-07 20:57

What does the innerexception property show?

I have no blog...

Re: Catch C++ exception in C#

Not Knuth16-Oct-07 5:26

Not Knuth

16-Oct-07 5:26

Liam O`Hagan wrote:
What does the innerexception property show?

The inner exception is null.

Re: Catch C++ exception in C#

Marshall16-Oct-07 6:11

Marshall

16-Oct-07 6:11

Not Knuth wrote:
I can not change the code in the DLL. How can I catch these (C++) exceptions and get the string info they contain?

I have recently encountered a similar situation. After a good bit of research and testing I can tell you that the best approach is to wrap the DLL in a managed assembly where you catch the C++ exception and then throw a managed exception in its place. (As described previously in the reply from led mike.)

You can grab the string out of the C++ exception and insert it in one of the exception classes defined in the framework or in your own derived from one of them. The framework doesn't provide any method to automatically marshal the string message in a C++ exception to a managed object.

Marshall

If you continue to do the same things you always did,
don't be surprised if you get the same results you always got.

Re: Catch C++ exception in C#

Not Knuth16-Oct-07 7:47

Not Knuth

16-Oct-07 7:47

Thank you.

Prevent Monitor Standby and ScreenSaver Activation

Sukhjinder_K15-Oct-07 6:05

Sukhjinder_K

15-Oct-07 6:05

Hi, I'm writing a MediaPlayer so I need to keep the monitor on and screen saver disabled during the life of my application. I understand that I need to handle certain windows messages SC_SCREENSAVE, SC_MONITORPOWER but I'm not sure how. So Please Advice

Thanks...

Re: Prevent Monitor Standby and ScreenSaver Activation

led mike15-Oct-07 6:42

led mike

15-Oct-07 6:42

http://msdn2.microsoft.com/en-us/library/ms646360.aspx[^]

Some code which can do the trick

Sukhjinder_K15-Oct-07 6:58

Sukhjinder_K

15-Oct-07 6:58

I got the following suggestion from someone
START
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_SYSCOMMAND:

switch (wParam)
{
// disable screen saver and monitor power-saving mode
case SC_SCREENSAVE:
case SC_MONITORPOWER:

return 0;
}

break;

case WM_DESTROY:

PostQuitMessage(0);

return 0;
}

return DefWindowProc(hwnd, message, wParam, lParam);
}
END

I goggled and tried to find various Constants used and replaced them with their values

protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
//case WM_SYSCOMMAND: //REPLACED
case 0x0112:

switch (m.WParam.ToInt32())
{
// disable screen saver and monitor power-saving mode

//case SC_SCREENSAVE: //REPLACED
case 0xF140:

//case SC_MONITORPOWER: //REPLACED
case 0xF170:

return;
}
break;
//case WM_DESTROY: //REPLACED
case 0003:
PostQuitMessage(0); // Wont Compile in C#
return;
}

base.DefWndProc(ref m);
//return DefWindowProc(hwnd, message, wParam, lParam);
}

NOw the Function PostQuitMessage(0) wont compile and without my whole Control layout goes wrong

I checked the link you provided but being very new to Windows Programming & C# I dont know how to use all this.

So your thoughts...

Thanks...

Re: Some code which can do the trick

Skippums15-Oct-07 7:30

Skippums

15-Oct-07 7:30

Include the following in your code:

[DllImport("user32.dll")]
public external void PostQuitMessage(int returnVal);

Jeff

Re: Some code which can do the trick

Sukhjinder_K15-Oct-07 18:35

Sukhjinder_K

15-Oct-07 18:35

After Updating the code and running my observations are that my MainForm does not show anymore and the app just exits (Runs fine after removing the following bit of code).

[System.Runtime.InteropServices.DllImport("user32.dll")]<br />
		public static extern void PostQuitMessage(int returnVal);<br />
		<br />
		protected override void WndProc(ref Message m)<br />
		{<br />
			switch (m.Msg)<br />
			{<br />
				case 0x0112:<br />
					//case WM_SYSCOMMAND:<br />
<br />
					switch (m.WParam.ToInt32())<br />
					{<br />
							// disable screen saver and monitor power-saving mode<br />
						case 0xF140:<br />
							//case SC_SCREENSAVE:<br />
						case 0xF170:<br />
							//case SC_MONITORPOWER:<br />
<br />
							return;<br />
					}<br />
<br />
					break;<br />
<br />
					//case WM_DESTROY:<br />
				case 0003:<br />
					PostQuitMessage(0);<br />
				return;<br />
			}<br />
<br />
			//return DefWindowProc(hwnd, message, wParam, lParam);<br />
			base.DefWndProc(ref m);<br />
		}

Re: Some code which can do the trick

Skippums16-Oct-07 5:05

Skippums

16-Oct-07 5:05

Put in some breakpoints and find the path that the code is taking to exit your application. Then post the results here so we can get a better idea of what is going on. Why do you call base.DefWndProc instead of base.WndProc?

Jeff

Re: Some code which can do the trick

led mike15-Oct-07 7:41

led mike

15-Oct-07 7:41

Sukhjinder_K wrote:
being very new to Windows Programming

Sukhjinder_K wrote:
I'm writing a MediaPlayer

very new and writing a MediaPlayer

Sukhjinder_K wrote:
So your thoughts...

My thought is, that does not compute.

New to C# and Writing Media Player

Sukhjinder_K15-Oct-07 17:03

Sukhjinder_K

15-Oct-07 17:03

I have programmed in Java a lot. So I'm just new to Windows Programming and C# and have never done Windows Message handling (or anything having HWND in it) before. I was looking for a Free Media Player which had what I needed, I couldn't find one. So I decided to build one on my own. And I chose C# to learn a new Language/Platform.

Thanks for your thoughts Mike...

Re: Some code which can do the trick

Hariharan.R16-Oct-07 2:31

Hariharan.R

16-Oct-07 2:31

Did you check it switching to appropriate Case block?

Solution

Sukhjinder_K16-Oct-07 18:27

Sukhjinder_K

16-Oct-07 18:27

Thanks Everybody for your help. Here is the Solution

const int WM_SYSCOMMAND = 0x0112, SC_SCREENSAVE = 0xF140, SC_MONITORPOWER = 0xF170;<br />
protected override void WndProc(ref Message m)<br />
{<br />
	if( m.Msg == WM_SYSCOMMAND )	//Intercept System Command<br />
	{<br />
		if( m.WParam.ToInt32() == SC_SCREENSAVE || m.WParam.ToInt32() == SC_MONITORPOWER )<br />
		{	//Intercept ScreenSaver and Monitor Power Messages<br />
			//MessageBox.Show("Reached SC/PowerCondition");<br />
			return;<br />
		}<br />
	}			<br />
	base.WndProc(ref m);<br />
}

How to read JavaScript's variables values in webBrowser control using C#

A.Asif15-Oct-07 5:41

A.Asif

15-Oct-07 5:41

Hi All,

I am writting a C# project in which am using Browser Control. The object of this project to read values of JavaScript's variables values on the current page ,and add those values to ListBox control. Can anybody show me how to do this. Please help if you can I need to do this ASAP for my job.

Thanks,

Asif

Re: How to read JavaScript's variables values in webBrowser control using C#

led mike15-Oct-07 6:36

led mike

15-Oct-07 6:36

A.Asif wrote:
am using Browser Control.

There are many articles on MSDN and I imagine some on CodeProject as well for using the Browser Control in C#, try starting there.

Re: How to read JavaScript's variables values in webBrowser control using C#

A.Asif15-Oct-07 9:30

A.Asif

15-Oct-07 9:30

I did research almost erevry site including microsoft but found no luck to my perticullar problem.
So please help if you can

Thanks,

Asif

Re: How to read JavaScript's variables values in webBrowser control using C#

leppie16-Oct-07 2:45

leppie

16-Oct-07 2:45

Add a reference to the MSHTML.dll and cast to the DOM types as explained in some document you read (you said you did them all). Then simply use the DOM to get the values.

xacc.ide

The rule of three: "The first time you notice something that might repeat, don't generalize it. The second time the situation occurs, develop in a similar fashion -- possibly even copy/paste -- but don't generalize yet. On the third time, look to generalize the approach."

Re: How to read JavaScript's variables values in webBrowser control using C#

A.Asif16-Oct-07 3:34

A.Asif

16-Oct-07 3:34

Thanks for your help! I am trying DOM but don't seems to work for me, can you please show me or send me some sytax how to get this values. I'll really apreciate your help.

Thanks

Asif

Getting text from one form into second form

MumbleB15-Oct-07 5:37

MumbleB

15-Oct-07 5:37

Hi Guys. I have a very stupid/simple question for you. I have two forms in my project, one a logon form called from my main form. When the user enters his username on the logon form I want to move the username into a label on my mainform. Can somebody please advise me on how to do this? Sigh | :sigh:

Thanks in advance.

Re: Getting text from one form into second form

Giorgi Dalakishvili15-Oct-07 5:46

Giorgi Dalakishvili

15-Oct-07 5:46

Have a look at this: Passing Values between Forms in .NET 1.x with C# and VB.NET examples[^]

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#endregion

how to track backgroundworker threads

jikubhai15-Oct-07 5:28

jikubhai

15-Oct-07 5:28

I am using backgroundworker thread in my application... i need to track each background worker and need to show the status in a datagrid ...

my application is used for database administrating ...

backups
restore
attaching

so various activities are going in different background workdes and their status need to show on a datagrid ... and each row in the datagrid should updated correctly ....

can someone write a small piece of code ....

thankzzzzzzzz

A123-B321

Event Listeners

Ennis Ray Lynch, Jr.15-Oct-07 5:41

Ennis Ray Lynch, Jr.

15-Oct-07 5:41

Have your background threads fire events for different states. Then your UI thread can listen to those events and respond appropriately.

You can also poll the status of the background threads by keeping track of the object reference, however, the event model is easier.

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