C#

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Tape Drive access Shaun Becker31-Mar-04 9:38 Shaun Becker 31-Mar-04 9:38  Is it possible to read, write, and perform drive maintenance(cleaning, inventory, etc.) on a tape drive from C#? Thanks alot Re: Tape Drive access Heath Stewart31-Mar-04 9:53 Heath Stewart 31-Mar-04 9:53  Is it possible? Sure. Would anyone sane want to do it? Absolutely not. Tape drive access is a very low-level, huge set of operations. You'll need to P/Invoke so many functions and declare so many structs and consts/enums that you'll probably never get to the meat of the development, unless you can find some COM control to interop or a wrapper DLL that you can P/Invoke, but you probably won't since this is not something that consumers typically "play with". The software you use with your drive (Veritas Backup, et. al.) may have some undocumented APIs you could P/Invoke, but as they're most likely undocumented for a reason you'll have a REALLY tough time. See the Windows DDK (driver development kit) for details. It's huge and it's ugly.   Microsoft MVP, Visual C# My Articles Endless Mouse Move Events Darryl Borden31-Mar-04 9:24 Darryl Borden 31-Mar-04 9:24  I have an object of type UserControl that I occasionally have problems with. Normally, when I move the mouse over the object, windows will generate a mouse move event as advertized - only when the mouse moves. Occasionally, however, windows goes crazy on me and generates a gazillion mouse move events for as long as the mouse is over the object and it is not even moving. I get so many of these events that it inhibits the application from performing until I move the mouse off the object. Has anyone seen this type of behavior before and, if so, was there anything you could do about it? Darryl Borden Principal IT Analyst darryl.borden@elpaso.com Re: Endless Mouse Move Events leppie31-Mar-04 9:49 leppie 31-Mar-04 9:49  You are probably doing a wrong invalidate during the event handling, I have seen the same behaviour on the PropertyGrids TypeConvertors. top secret Re: Endless Mouse Move Events Bryan White31-Mar-04 10:32 Bryan White 31-Mar-04 10:32  Yup - I've experienced it. It was an OpenGL control with mouse interaction, and didn't bother to work out WHY it happened - I just stopped it being a pain with following pseudocode: PointOrWhatever savedPosition; void HandleMouseEvent(whatever args) { if(args.position == savedPosition) return; DoMyMouseMovingStuff(); savedPosition = args.position; } Regards Brewman CreateProcess call.... RB@Emphasys31-Mar-04 8:27 RB@Emphasys 31-Mar-04 8:27  I'm wondering if the codeproject guru's might have an answer to my little riddle. I have plenty of code to call the createprocess function of the coredll.Dll assembly. Here is my quandry, all of those api declerations along with the actual call itself use a part of the framework that is not included with the compact framework. For instance I know you can use the Process class to create process's, but not with the cf. I have some code that defines the function but defines various parameters through the System.Web namespace, also not included with the cf. Ill post my decleration, any help would be appreciated. [DllImport("CoreDll.DLL", SetLastError=true)] private extern static int CreateProcess(String imageName, String cmdLine, IntPtr lpProcessAttributes, IntPtr lpThreadAttributes,Int32 bool InheritHandles, Int32 dwCreationFlags,IntPtr lpEnvironment, IntPtr lpszCurrentDir,byte [] si, ProcessInfo pi ); Thanks again, Ryan Re: CreateProcess call.... Heath Stewart31-Mar-04 8:57 Heath Stewart 31-Mar-04 8:57  Sorry, but I'm not really seeing a relevent problem statement there. Are you saying your P/Invoke declaration isn't working? And what do you mean you're defining various parameters through the System.Web namespace? Your declaration look okay to me. You might want to add CharSet=CharSet.Unicode to your DllImportAttribute to be sure that strings are marshalled appropriately. If you don't like calling this often from your code, encapsulate it in a public static method or something.   Microsoft MVP, Visual C# My Articles Re: CreateProcess call.... RB@Emphasys31-Mar-04 9:07 RB@Emphasys 31-Mar-04 9:07  I apoligize for not being more clear. I can't use the statement because the ProcessInfo class which is the last argument is part of the System.Web namespace which isnt included in the cf. I was curious if anyone knew of another way of declaring the function without using the ProcessInfo class for the last argument. Thanks, Ryan Re: CreateProcess call.... Heath Stewart31-Mar-04 9:12 Heath Stewart 31-Mar-04 9:12  Just call the parameter as something else. The fact is that you have to define that struct that the P/Invoke statement takes. You could call it Asdf and it won't matter, so long as the struct matches the structure defined in Windows. If you like the name ProcessInfo, then define it yourself and just qualify it with the namespace you define it under.   Microsoft MVP, Visual C# My Articles Re: CreateProcess call.... RB@Emphasys31-Mar-04 9:14 RB@Emphasys 31-Mar-04 9:14  Thanks Heath Re: CreateProcess call.... RB@Emphasys31-Mar-04 9:48 RB@Emphasys 31-Mar-04 9:48  For future reference I was able to just use IntPtr.Zero for the parameter, thanks again Heath. Ryan Plotting on a Map using latitudes/longitudes(GPS) sibish n b31-Mar-04 7:47 sibish n b 31-Mar-04 7:47  Can anyone help me in plotting on a map using latitudes and longitudes. Am doing a project in using GPS. The methods i used doesn't give enough accuracy. Can anyone give suggestions to improve accuracy. sibish Re: Plotting on a Map using latitudes/longitudes(GPS) Bryan White31-Mar-04 8:43 Bryan White 31-Mar-04 8:43  Define 'accuracy' and 'plot'. What method did you use? What is its purpose? I have experience of plotting lat/long country outlines and GPS data onto a computer screen. Treat the lat/long as a coordinate in 3D space (polar coords with constant Radius - or is this the inaccuracy you talk about? Do you want a more accurate geoid(earth-shape)?). Convert to Cartesian coords (X, Y, Z) Then project onto a 2D surface. Which projection do you want to use? There are hundreds, but probably less than a dozen that cover 99% of needs. Each projection has its own strengths and weaknesses (read: inaccuracies). e.g. a Mercator allows sailors (& others) to travel at a constant bearing to reach their destination, but distorts shapes. To allow 'autosizing' of the display, I just used the min/max lat/long rectangle diagonal & scaled it - fine unless you're working near the poles (I was using Europe, US & Canada - Canada was almost a problem!). Give more specific details of what you're doing & want to achieve, and you could receive more specific help. Regards Brewman Re: Plotting on a Map using latitudes/longitudes(GPS) mhmoud rawas31-Mar-04 9:52 mhmoud rawas 31-Mar-04 9:52  Dear Sir, i have already write an application for that issue, first of all you have to calibrate the map by putting thin point on it, by this way you can relate the coordinates oof the map with the UTM coordinates by this control points you will get an accurate tracking, the tracking error will be not more that 2-3 meters if you have any other Q you can ask me Regards Mhmoud Rawas ------------ Software Eng. Re: Plotting on a Map using latitudes/longitudes(GPS) sibish n b1-Apr-04 21:56 sibish n b 1-Apr-04 21:56  Hi, Can you send me your application source code.Send to sibbsnb@yahoo.com Thank you sibish Re: Plotting on a Map using latitudes/longitudes(GPS) mhmoud rawas2-Apr-04 4:18 mhmoud rawas 2-Apr-04 4:18  Dear Sir, Exuse me sir it is top secure code i could not send it to you gut if you have any quistion you can ask me Regards Mhmoud Rawas ------------ Software Eng. Re: Plotting on a Map using latitudes/longitudes(GPS) - another thought Bryan White31-Mar-04 10:49 Bryan White 31-Mar-04 10:49  If you're plotting simple Lat/Long as X/Y (or is that Y/X?) and your Long is too short(?!) on the map (i.e. if you 'walk' in a square and an oblong appears) ... then if: - area is small (less than say 100 miles/kilometres) - not a polar region then let LonAdj = Lon/cos(LatOfMapMidPoint) and plot that. If a polar region, plot as polar (radius = 90-abs(Lat) & theta/angle = Long * sign(Lat)) Regards Brewman Double Buffering on System controls? Snowjim31-Mar-04 4:46 Snowjim 31-Mar-04 4:46  Hey I have now used Double buffering to the background picture of a 1024*712 form, it simes like it is much smother, but still i could notice some lag when moving the form around. 1. Now i will place some System Controls(own made controls) in this form, do i have to use the double buffert inside this controllers to? or do the form(with double buffert) fix double buffert to al the controls? 2. this controls haves som grafic, like buttons and so on, not to big with other words. shold i draw this images on the buttons and so on in the OnPaint override or is it okay to just load them direct in to the buttons(maby not to big difrrence, when thay isent that big?). 3. What picture format is less expensive to handle? png, jpeg, bmp, gif... and what quality? maby no compression at al is bether then compressed? //Jimmy Re: Double Buffering on System controls? Heath Stewart31-Mar-04 5:03 Heath Stewart 31-Mar-04 5:03  Are they system controls, or your controls? In #1, that isn't clear. You typically don't need to modify system controls because most aren't drawn at all by .NET. Windows Forms controls encapsulate their Common Control equivalents which draw themselves using GDI outside the realm of .NET. Ever wonder how Microsoft keeps the Win32 controls and the .NET controls looking the same? Because they are the same. Bitmaps (bmp) are the best way to go. These are used primarily throughout much of the code that makes up Windows, Office, Photoshop, and most other programs you can think of. Up until a few years ago when more and more applications started using bits of the Internet Explorer WebBrowser control and MSHTML, that's all that was supported without your own rendering. Bitmaps are uncompressed (well, some may be RLE compressed but this is rare when dealing with Windows graphics), where the others are compressed and, in the case of a GIF, indexed.   Microsoft MVP, Visual C# My Articles Re: Double Buffering on System controls? Snowjim31-Mar-04 5:14 Snowjim 31-Mar-04 5:14  When i wrote System controls, then i ment Windows Control Library(my bad). this controls is then applayed to my form. in the Windows Control Library i adds buttons and listboxens and so on, and in many cases there will be grafik applayed to this contrlls like buttons and listboxes. This pictures is not big, but maby i have to draw then my self in the onpiant to get an overal bether preformans of my application? And will i have to use Double bufferting(SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.DoubleBuffer | ControlStyles.UserPaint, true);) on this Windows control Library to get them to use double buffering. if have got this right? double buffering (SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.DoubleBuffer | ControlStyles.UserPaint, true);) is used to first load the picture in to the memory and then display it, and when it is repainted its repainted in the memory first and then displayed? And to override the OnPaint and draw some of the pictures myself is another way to get bether preformans, but i can use only the buffering or only the overridden onpiant, thay have not realy a connection ?? Thankt alot with the fast answare //Jimmy Re: Double Buffering on System controls? Heath Stewart31-Mar-04 5:30 Heath Stewart 31-Mar-04 5:30  Yes, that's how you enable double-buffering and that's how it works. It draws the on-screen bitmap in memory and then pushes it to the device context.   Microsoft MVP, Visual C# My Articles Re: Double Buffering on System controls? Snowjim31-Mar-04 5:36 Snowjim 31-Mar-04 5:36  Okay, good, Tanks! But do i have to use the double bufferting in the Windows Library controls that i make? or will the main form(project)s doubel buffering configuration applay to the controls that are applayed to the form? //Jimmy Re: Double Buffering on System controls? Heath Stewart31-Mar-04 5:43 Heath Stewart 31-Mar-04 5:43  You really don't need to enable double-buffering for everything. For something simple like display text or an image on a button, you really don't need it. Double-buffering is most beneficial when used to display UIs that require a lot of processing to display their graphics, or if you want something like smooth scrolling text (a common example used for double-buffering tutorials).   Microsoft MVP, Visual C# My Articles AutoScrolling with a RichTextBox znize31-Mar-04 4:00 znize 31-Mar-04 4:00  I am trying to create a chat window (as a controller), and my problem is that i cant get the scroller to move to the bottom (follow the new strings that are added), is there any way to make it auto scroll to the bottom? I have tryed this (when i recieve a new message) but it seems that it wont focus?: rtxPublic.Focus(); rtxPublic.SelectionStart = rtxPublic.Text.Length; rtxPublic.SelectionLength = 0; rtxPublic.ScrollToCaret(); rtxPublic.Update(); When i do this in a form it works but not as a controller?? Please help! Thanks /Johan Re: AutoScrolling with a RichTextBox leppie31-Mar-04 6:10 leppie 31-Mar-04 6:10  IIRC you need to invoke that via control.Invoke() , so wrap them commands in a methods and be sure to invoke the method rather than call it directly. top secret

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