Transcript The 100% Inspiration Tour

The 100%
Inspiration
Tour
Exploring the .NET
Framework with C#
David Chalmers
Academic Team, Microsoft UK
[email protected]
http://blogs.gotdotnet.com/davidcha
Topics
Exploring the .NET Framework SDK
What actually is .NET?
Understanding key Framework concepts
Delving into the Common Language
Runtime
Introducing the C# programming language
What is .NET?
Software for connecting people,
information, systems and devices?
Runtime for executing code
Tools to help develop applications
Server products to manage applications
Value-added services
Managed environment for developing and
executing components
.NET Framework SDK
A platform for building
XML Web services
Windows Applications
Web Applications
Mobile Device Applications
Standards based
Enhances developer productivity
Simplifies application development
Makes delivery of complex applications possible
Creating Our First .NET
Application
A Modest Application!
Module Module1
Sub Main()
10:
Console.WriteLine(“I rock”)
20:
GoTo 10
End Sub
End Module
Introducing C#
Less typing!
Object Orientation
Better control structures
Combines best features of
C/C++
Java
Visual Basic
Languages with {};
using System;
public class HelloWorld
{
static void Main(string[] args)
{
Console.WriteLine(s);
}
}
A Improved ‘Hello, World’
using System;
public class HelloWorld
{
static void Main(string[] args)
{
string[] strArray = {“I rock”, “You rock”,
“We all rock”};
foreach(string s in strArray)
{
Console.WriteLine(s);
}
}
}
C# Program Structure
using System;
namespace System.Collections
{
public class Stack
{
Entry top;
public void Push(object data) {
top = new Entry(top, data);
}
public object Pop() {
if (top == null) throw new InvalidOperationException();
object result = top.data;
top = top.next;
return result;
}
}
}
Properties
Properties are “smart fields”
Natural syntax, accessors, inlining
public class Button: Control
{
private string caption;
public string Caption {
get {
return caption;
}
set {
caption = value;
Repaint();
}
}
}
Button b = new Button();
b.Caption = "OK";
String s = b.Caption;
Attributes
public class OrderProcessor
{
[WebMethod]
public void SubmitOrder(PurchaseOrder order) {...}
}
[XmlRoot("Order", Namespace="urn:acme.b2b-schema.v1")]
public class PurchaseOrder
{
[XmlElement("shipTo")] public Address ShipTo;
[XmlElement("billTo")] public Address BillTo;
[XmlElement("comment")] public string Comment;
[XmlElement("items")]
public Item[] Items;
[XmlAttribute("date")] public DateTime OrderDate;
}
public class Address {...}
public class Item {...}
Indexers
Indexers are “smart arrays”
Can be overloaded
public class ListBox: Control
{
private string[] items;
public string this[int index]
get {
return items[index];
}
set {
items[index] = value;
Repaint();
}
}
}
{
ListBox listBox = new ListBox();
listBox[0] = "hello";
Console.WriteLine(listBox[0]);
foreach Statement
Iteration of arrays
public static void Main(string[] args) {
foreach (string s in args) Console.WriteLine(s);
}
Iteration of user-defined collections
foreach (Customer c in customers.OrderBy("name")) {
if (c.Orders.Count != 0) {
...
}
}
C# – The Big Ideas
Everything is an Object
Traditional views
C++, Java: Primitive types are ‘magic’ and do not
interoperate with objects
Smalltalk, Lisp: Primitive types are objects, but at
great performance cost
C# unifies with no performance cost
Deep simplicity throughout system
Improved extensibility and reusability
New primitive types: Decimal, SQL…
Collections, etc., work for all types
C# – The Big Ideas
Building Robust Code
Garbage collection
No memory leaks and stray pointers
Exceptions
Error handling is not an afterthought
Type-safety
No uninitialised variables, unsafe casts
Versioning
Pervasive versioning considerations in all
aspects of language design
Advanced Coding Capabilities
class FileStream: Stream
{
int handle;
public unsafe int Read(byte[] buffer, int index, int count) {
int n = 0;
fixed (byte* p = buffer) {
ReadFile(handle, p + index, count, &n, null);
}
return n;
}
[dllimport("kernel32", SetLastError=true)]
static extern unsafe bool ReadFile(int hFile,
void* lpBuffer, int nBytesToRead,
int* nBytesRead, Overlapped* lpOverlapped);
}
Objects and Types
Need a way of grouping code with the
data it operates on
Classes
Primitive types
Operations on those types
Ensuring interoperability
Common Type System
The Common Language Specification
(CLS)
Libraries and the CLS
Classes for objects that are generally
useful or support specific application
types are built into libraries
Most of the base-class libraries are CLS
compliant
Can be called by any component you
create in a CLS-compliant programming
language
Don’t Start from Scratch!
Lots of good content out there to learn from
Quick Start Tutorials
samples.gotdotnet.com/quickstart
ASP.NET Starter Kits
www.asp.net
Sample Applications
IBuySpy
Pet Store
Many more …
Delving into Source Code
What’s Under the Hood?
Assemblies
IL
Metadata
Execution
Class Loader
Security Verification
Managed Execution
Just In Time Compilation
Garbage Collection
The .NET Framework
C++
C#
JScript
…
Common Language Specification
ASP.NET
Windows Forms
Data and XML
Common Language Runtime
Windows
COM+ Services
Web Matrix
Base Class Library
Visual Studio.NET
VB
Common Language Runtime
Base Class Library Support
Thread Support
COM Marshaler
Type Checker
Exception Manager
Security Engine
Debug Engine
IL to Native
Compilers
Code
Manager
Class Loader
Garbage
Collector
Compilation and Execution Model
Compilation
Source
Code
Language
Compiler
Native
Code
JIT
Compiler
Execution
Code (IL)
Assembly
Metadata
At installation
or the first time
each method is
called
Summary
Flexible platform for sharing code and
data across
languages
Processes
Machines
Sites or domains
Execution Environment
Powerful language support
Great tools and utilities for developers
Further Resources
.NET Framework SDK
msdn.microsoft.com/netframework
msdn.microsoft.com/vstudio
Further Reading
Applied .NET Framework Programming. Richter, J.
(2002); Microsoft Press
www.microsoft.com/mspress/books/5353.asp
Inspiration Tour Site
www.microsoft.com/uk/inspiration
© 2003 Microsoft Corporation. All rights reserved.
This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.