//str_len returns the length of str
int str_len(char* str) {
int len; len = 0;
for (int i = 0; str[i] != '\\0'; i++)
{
len ++;
}
return len;
}
void main() {
char* website = "www.github.com";
int len = str_len(website);
printf("length = %d n", len);
}
OUTPUT length = 17
App.xaml.cs
public partial class App : Application {
public string sName { get; set; }
public static new App Current
{
get { return Application.Current as App; }
}
...
...
}
Page1.xaml.cs
public partial class Page1 : PhoneApplicationPage {
public string _sName;
public Page1()
{
InitializeComponent();
_sName = App.Current.sName;
}
}
Preventive measure steps:
It's good to setup sign-in options in order to have one or more ways to login to your PC
Go to charm bar select 'Change PC Settings'
Select Users
Use 'Sign-in options' to use 'Picture Password' and 'PIN' password
1. Press the Windows+R keys to open the Run dialog, type cleanmgr, and press Enter.
2. Select the Windows drive, and click/tap on OK. NOTE: You will not see this window unless you have more than one drive or partition on your computer with a drive letter.
3. Click/tap on the Clean up system files button
4. Click/tap on the Previous Windows installation(s) box to check it, and click/tap on OK. (see screenshot below)
5. Click/tap on Delete Files.
6. When Disk Cleanup finishes, the C:Windows.old folder will be deleted.
Install Visual Studio 2010 Professional or Visual Studio 2010 Ultimate
Install Microsoft VisualStudio 2010 ServicePack1 http://www.microsoft.com/en-in/download/details.aspx?id=23691
or
If you don’t have Visual Studio 2010 Professional or Visual Studio 2010 Ultimate go for 3) Visual Studio 2010 Express for Windows Phone (MSDN) http://www.microsoft.com/visualstudio/en-us/products/2010-editions/windows-phone-developer-tools
After installing Visual Studio 2010 Professional or Visual Studio 2010 Ultimate or Visual Studio 2010 Express for Windows Phone install following Windows Phone SDK’s
Install Microsoft XNA Game Studio 4.0 http://www.microsoft.com/en-in/download/details.aspx?id=23714
Install Windows Phone SDK 7.1 SDK http://www.microsoft.com/en-us/download/details.aspx?id=27570
Install Windows Phone SDK 7.1.1 SDK Update http://www.microsoft.com/en-us/download/details.aspx?id=29233
In this tutorial we will be creating
MathComp which is a DLL or Inproc server and exposes the Add and Sub functions.
An MFC Dialog Based Application which acts like a Client for MathComp
For complete tutorial refer Tutorial
The major code portions of WPF are.
PresentationFramework, PresentationCore, and milcore WPF. PresentationFramework, PresentationCore are managed components but only milcore is an unmanaged component Milcore is developed in unmanaged code in order to enable tight integration with DirectX. All display in WPF is done through the DirectX engine, allowing for efficient hardware and software rendering.
1. Presentation Framework
Most of the important WPF elements are in Presentation Framework. Presentation Framework Provides high-level services like layout, data binding, command handling.
2. Presentation Core
Presentation provides .NET API that uses rendering services for the MIL. During graphics programming we work with Core API.
3. Milcore
The composition engine in milcore (Media Integration) is extremely performance sensitive. MIL takes Bitmaps, Vectors, and media render them to the DirectX
Windows Presentation Foundation is the successor to Windows Forms for Microsoft Desktop Application development. WPF uses XAML to create visible User Interface (UI) elements like (buttons, listboxes, editboxes, etc).
WPF applications allows take advantage of the best attributes of diverse systems, such as DirectX (3-D and hardware acceleration), Adobe Flash (animation support), and HTML (declarative markup and easy deployment), styles, templates, documents and typograph.
The advantages of WPF applications include:
Declarative programming – WPF uses Extensible Application Markup Language (XAML) declarative programming to define the layout of application objects and to represent 3-D models, among other things. This allows graphic designers to directly contribute to the look and feel of WPF applications.
Tight multimedia integration –WPF provides consistent programming model to create -D graphics, video, speech, and rich document viewing.
Resolution independence –WPF uses vector graphics to make the applications resolution-independent. WPF Applications can shrink or enlarge elements on the screen, independent of the screen’s resolution.
Hardware acceleration – WPF is built on top of Direct3D, which offloads work to graphics processing units (GPUs) instead of central processor units (CPUs). This provides WPF applications with the benefit of hardware acceleration, permitting smoother graphics and enhanced performance.
Rich composition and customization – WPF controls are easily customizable. We need not write any code to customize controls in very unique ways. WPF also lets you create skins for applications that have radically different looks.
Easy deployment – WPF provides options for deploying traditional Windows applications (using Windows Installer or ClickOnce).
Culturally aware controls – static text in controls and the return data for the String function are modified according to the culture and language specified by the end user's operating system.
WPF is also more suitable for applications with rich media content than Windows Forms applications. This includes applications using:
WPF is also great if you need to create a skinned user interface, or if you need to bind to XML data, or dynamically load portions of a user interface from a Web service, or want to create a desktop application with a Web-like navigation style.
WPF stores its data more efficiently hence individual objects will be small, but there tend to be more objects in WPF than in WinForms .This would require more RAM than Windows Application.
CPU utilization will go up compared to WinForms WPF objects onscreen takes more CPU as normal WinForms rendering (again depending on the requirement).
Definition: XAML (zammel) is an XML-based declarative markup. We can create visible User Interface (UI) elements like (buttons, listboxes, editboxes, etc) using XAML.
XAML files are XML files .xaml file name extension encoded as UTF-8.
Example:
C# Button Compile (Design-time) and Execute (Runtime) where as XAML Button Load, Parse,Render and Display
COM Threading Models / Apartment Model
Definition: Multithreading in COM is referred to as the apartment model in COM
Apartment
The COM apartment is a conceptual entity that allows us to think about components and their clients in a logical way
An apartment is not a thread, but a thread belongs to only one apartment.
An apartment is not an instance of a COM object, but each COM instance belongs to only one apartment.
A process can have one or more apartments, depending on its implementation.
Apartments are created or entered by calling the CoInitialize or CoInitializeEx function. Each thread that calls CoInitialize(0) or CoInitializeEx( 0, COINIT_APARTMENTTHREADED )
Differences between STA and MTA
| No | Feature | STA | MTA |
| 1 | Synchronization provided by COM | YES | NO |
| 2 | Uses Windows message queues | YES | NO |
| 3 | Can have multiple threads in an apartment | NO | YES |
| 4 | Must marshal interface pointers between the threads in the same apartment | N/A | YES |
| 5 | Must marshal interface pointers between apartments | YES | YES |
| 6 | Must call Coinitialize() in every thread that uses a COM Service | YES | YES |
| 7 | Performance | Slow | Fast |
NOTE: ATL object wizard allows you to set the threading model. The values can be
| Threading Model | Description |
| Single / No Value | Object knows nothing about threads |
| Apartment | STA |
| Free | MTA |
| Both | Both STA & MTA |
There are two types of win32/MFC threads.
User-interface thread: these types of threads are associated with one or more windows. These threads have message loops that keep the window alive and responsive to the users input.
Worker thread: these threads are associated with background processing and are not associated with a window. These types oh threads does not use message loops.
NOTE: A single process can have multiple user interface threads, multiple worker threads.
COM uses same type of threads with different names.
Apartment threads (User Interface Thread): This thread owns the component it creates. COM synchronizes, all calls to the component. The component does not need to be threading safe. COM does all of the marshaling and synchronization.
Free threads (Worker Thread): COM does not synchronize the calls. Ant thread can access the component. These are free to use. The component must be threading safe. Marshalling is not necessary and component’s job to synchronize.
NOTE: One process can have single apartment or multiple apartments. In-proc server is example for single process with different apartments (server apartment, client apartment both are in same exe).
Out of-proc server is example for single process with single thread.