Day 5 - Coding for the Morning Session
Nuwan
// file : prg1.cs
public class test1 {
internal void method1() {
System.Console.WriteLine("hello");
}
}
// file : prg2.cs
public class test2 {
public void method2() {
System.Console.WriteLine("hello");
}
public static void Main() {
test1 myob = new test1();
myob.method1();
}
}
Note : We can compile both programs using the following command
csc prg1.cs prg2.cs /out:prgs
This will create an exe called prgs
-----------------------------------------
An assembly is distributable file which is either an exe or an dll.
We can compile prg1.cs as a dll using the following command
csc prg1.cs /target:libarary out:prg1.dll
This will create a dll file called prg1.dll
We can refer to this dll from the main program as follows from the
command line
csc prg2.cs /reference:prg1.dll
This will create an exe file called prg2.exe
If you look at ILDASM you will note that prg2.exe has a reference to
prg1.dll
In Visual Studio .NET you can have a reference to a dll by add one from
reference from the solution explorer.
------------------------------------------------
Note : Internal Access
If you change some of the public classes in the dll (prg1.cs) to
internal then you cannot access them from the prg2.cs main program.
internal access is public within the current assembly, but private
outside.
------------------------
Namespace Examples
// --------------------- prg1.cs
namespace Graphics {
public class test1 {
internal void method1() {
System.Console.WriteLine("hello");
}
}
}
// ---------------- prg3.cs
namespace SLIIT {
public class test1 {
public void method1() {
System.Console.WriteLine("hello");
}
}
}
public class test2 {
public void method2() {
System.Console.WriteLine("hello");
}
public static void Main() {
SLIIT.test1 mt = new SLIIT.test1();
mt.method1();
}
}
//------------------------
If you take the following example
namespace SLIIT.Graphics.Projects {
class XYZ {
}
}
You need to access XYZ as SLIIT.Graphics.Projects.XYZ;
It would be easy if have using the using clause
using SLIIT.Graphics.Projects;
Now you can directly access all the classes, structs defined under this
namespace.
Namespaces are used to avoid conflicts and are defined at a logical
level.