8.2.3 Using a .NET Component
The .NET Component can be used the same way as any other Visual LANSA component.
Define an instance of a component.
Use the DEFINE_COM command. If the class does not have a constructor or has a constructor which takes no parameters then you may define the instance as either static or dynamic. Otherwise you must define the instance as dynamic.
Define_Com Class(#DOTNET1.TestClasses.MyClass) Name(#MyClass) Reference(*DYNAMIC)
If the class is a control, be sure to parent the control to the form so that it is visible on the form. You may then resize and move the control in Design view.
Define_Com Class(#DOTNET1.DotNetControls.WebBrowserX) Name(#Browser) Displayposition(4) Parent(#COM_OWNER) Tabposition(4)
Instantiating a dynamic instance
If the component instance has been defined as dynamic, the instance will need to be instantiated with either the *New or SET_REF commands. Either command allows you to specify a constructor.
How to define classes with static methods
To use static methods in a class you must define a component instance. The instance may be defined as static or dynamic. Once defined, static methods from the class may be called at any time. If a dynamic component instance has been defined, static methods may be called without instantiating the instance. This allows the use of static classes and also allows the instantiation of classes with private or protected constructors (assuming the class has static methods to instantiate itself).
*NEW
If the class does not have a constructor or has a constructor that takes no parameters, then you may specify no constructor or a constructor with no parameters. Otherwise the parameters should be passed similar to a method call.
Variable <= *New --- Fully qualified class name ------------------ >
>----------------------------------------------------------------- >
| |
-- .Constructor Name ------------------------------------------
| |
-- ( ----------------------------- ) -–
| |
------- Parameter -------
| |
---------<---------
SET_REF
For information, refer to the SET_REF in the .
Examples
C#
public ConstructorTests() {…}
public ConstructorTests( int aNumber ) {…}
public ConstructorTests( int aNumber, ref DateTime aDateTime, String aString ) {…}
RDML
Define_Com Class(#DOTNET1.TestClasses.ConstructorTests) Name(#LCom01) Reference(*DYNAMIC)
Define Field(#LNum01) Type(*INT) Length(4)
Define Field(#LStr01) Type(*CHAR) Length(50)
Define Field(#LDTime01) Type(*DATETIME) Length(26)
#LCom01 <= *New #DOTNET1.TestClasses.ConstructorTests
Set_Ref Com(#LCom01) To(*CREATE_AS #DOTNET1.TestClasses.ConstructorTests)
#LCom01 <= *New #DOTNET1.TestClasses.ConstructorTests.ConstructorTests()
Set_Ref Com(#LCom01) To(*CREATE_AS #DOTNET1.TestClasses.ConstructorTests.ConstructorTests)
#LCom01 <= *New #DOTNET1.TestClasses.ConstructorTests.ConstructorTests#2( #LNum01 #LDTime01 #LStr01 )
Set_Ref Com(#LCom01) To(*CREATE_AS #DOTNET1. TestClasses.ConstructorTests.ConstructorTests#2) Anumber(#LNum0501) Adatetime(#LDTi0501) Astring(#LStr0501)
Using properties and variables
Syntax
RDML Variable . .NET Property Name ----------------------------------------------- >
| |
-- [ --------------------------------- ] -–
| |
----------- Index -----------
| |
-----------<-----------
RDML Variable . .NET Variable Name
Examples
C#
public int Counter
{
get { return mCount; }
set { mCount = value; }
}
RDML
Define_Com Class(#DOTNET1.TestClasses.MyClass) Name(#NumericClass)
#NumericClass.Counter := 120
#STD_INT := #NumericClass.Counter
Begin_Loop Using(#STD_INT) To(#NumericClass.Counter) Step(2)
…
End_Loop
Calling Methods
Syntax
RDML Variable . Method Name ----------------------------------------------- >
| |
-- ( --------------------------------- ) -–
| |
-------- Parameter ----------
| |
-----------<-----------
Example
C#
public void
IncrementDateByDays(
ref DateTime dateTime,
int dayAdjustment )
{
dateTime = dateTime.AddDays( dayAdjustment );
}
RDML
Define_Com Class(#DOTNET1.TestClasses.MyClass) Name(#LClass01)
Define Field(#LDat01) Type(*DATETIME)
Define Field(#LDat02) Type(*DATETIME)
#LDat01 := '1954-04-25 10:04:00.000000'
#LDat02 := '1954-05-05 10:04:00.000000'
#LClass01.IncrementDateByDays( #LDat01 10 )
If ((#LDat01 = #LDat02))
…
Endif
C#
public String
DoubleIntegerReturnString(
int number,
out int result )
{
result = number * 2;
return String.Format( "Double {0} is {1}", number, result );
}
RDML
Define_Com Class(#DOTNET1.TestClasses.MyClass) Name(#LClass01)
Define Field(#LNum01) Type(*INT) Length(4)
Define Field(#LNum02) Type(*INT) Length(4)
Define Field(#LStr01) Type(*CHAR) Length(80)
#LNum01 := 411
#LStr01 := #LClass4101.DoubleIntegerReturnString( #LNum01 #LNum02 )
If (#LNum02 = (#LNum01 * 2))
…
Endif
Event Handling
Event handling functions are defined using the EVTROUTINE command. See the EVTROUTINE documentation in the for further details about this command. The basic syntax of the command is as follows:
EVTROUTINE --- HANDLING ( Variable Name . Event Name )------------ >
>----------------------------------------------------------------- >
| |
---- Parameter Name( Variable Name ) ---- ) -–
| |
--------------------<----------------
Example
C#
public class EventArgs1
{
private String mName;
public EventArgs1() { }
public String Name
{
get { return mName; }
set { mName = value; }
}
}
Public class EventTests
{
public event MyEventDelegate MyEvent;
public delegate void MyEventDelegate( String str, EventArgs1 eventArgs );
}
RDML
Define_Com Class(#DOTNET1.TestClasses.EventTests) Name(#EventTest)
Evtroutine Handling(#EventTest.MyEvent) Str(#s1) EventArgs(#c1)
#STD_TEXT := #s1
#STD_NAME := #c1.Name
Endroutine