Using Arrays
An array is a data structure that contains several variables of the same type. The variables are treated as a single collection. Although you can already create arrays in C/AL, you can now use arrays from the .NET Framework. Choosing whether to use a C/AL array or a .NET Framework array depends on how you intend to use the data.
For this scenario | Use this array type |
---|---|
Your C/AL code uses .NET Framework interoperability extensively, and you must share the array among many methods. | .NET Framework array |
Your C/AL code mostly uses basic C/AL types and does not interoperate with the .NET Framework. | C/AL array |
To use a .NET Framework array in C/AL, you must use the System.Array class in the .NET Framework class library, which is the class from which all arrays inherit. When interfacing with an array in C/AL, you must use the following methods of the System.Array
class to create and access elements in the array.
Method | Description |
---|---|
CreateInstance | Creates a new array instance that is passed to a method or property. |
SetValue | Sets a value in an array element. |
GetValue | Gets a value from an array element |
Many .NET Framework classes implement these methods. Therefore, they are available for you to use in C/AL code. If you are writing your own .NET Framework code and want to use it in Dynamics NAV, then you must implement these methods yourself.
In C/AL, some .NET Framework data types, such as strings, integers, and decimals, are automatically converted to C/AL types. If a .NET Framework array contains these data types, then you create an assembly that contains methods that return the information about the data types and then reference the assembly in the C/AL code. This concept is illustrated in the following examples.
Example: Using Native C/AL Data Types in a .NET Framework Array
The following example shows how you can use a .NET Framework array for an integer data type.
In Visual Studio, create a C# class library project called NavInteropHelper that contains a method that returns the information about the integer type as follows:
namespace Microsoft.Dynamics.Nav.NavInteropHelper; { public class WrapInt32 { public static Type GetTypeOfInt32() { return typeof(Int32); } } }
Build the project, and then copy the assembly to the Add-ins folder of the Microsoft Dynamics NAV Windows client installation folder. By default, the path of the installation folder is C:\Program Files\Microsoft Dynamics NAV\110\RoleTailored Client or C:\Program Files (x86)\Microsoft Dynamics NAV\100\RoleTailored Client.
In the development environment, open a Dynamics NAV object, open the C/AL code, and then create the following C/AL variables.
Variable name DataType SubType varDotNet DotNet 'NavInteropHelper, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.Microsoft.Dynamics.Nav.NavInteropHelper.WrapInt32 varArray DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Array arraySize Integer i Integer alData Integer On a trigger of the Dynamics NAV object, add the following C/AL code to create, fill, and implement the array.
// Sets the number of elements in the .NET Framework array. arraySize := 10; // Creates an instance of the .NET Framework array that contains the Int32 type. varArray := varArray.CreateInstance(varDotNet.GetTypeOfInt32(), arraySize); // Clears the object instance because it is no longer used. clear(varDotNet); // Sets the data in the array. FOR i := 0 TO (arraySize -1) DO varArray.SetValue(i+100,i); // Gets the array data and validates the content. The object that is returned by // GetValue is automatically converted into a C/AL integer in the assignment. FOR i := 0 TO (arraySize -1) DO BEGIN alData := varArray.GetValue(i); if alData <> (i+100) then error('Invalid array data in element %1, expected %2, actual %3', i, i+100, alData); END;
Example: Using User-Defined Classes in a .NET Framework Array
This example shows how you can use a .NET Framework array that includes user-defined classes.
In Visual Studio, create a C# class library project called NavInteropHelper that contains methods that return the information about the types as follows.
namespace Microsoft.Dynamics.Nav.NavInteropHelper; { public class WrapInt32 { public int Data { get; set; } public WrapInt32(Int32 value) { Data = value; } } }
Build the project, and then copy the assembly to the Add-ins folder of the Microsoft Dynamics NAV Windows client installation folder. By default, the path of the installation folder is C:\Program Files\Microsoft Dynamics NAV\110 RoleTailored Client or C:\Program Files (x86)\Microsoft Dynamics NAV\100 RoleTailored Client.
In the development environment, open a Dynamics NAV object, open the C/AL code, and then create the following C/AL variables.
Variable name DataType SubType varDotNet DotNet 'NavInteropHelper, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.Microsoft.Dynamics.Nav.NavInteropHelper.WrapInt32 varArray DotNet 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.System.Array arraySize Integer i Integer alData Integer On a trigger of the Dynamics NAV object, add the following C/AL code to create, fill, and implement the array.
// Sets the number of elements in the .NET Framework array. arraySize := 10; // Creates an instance of the .NET Framework object so the type information can be retrieved. varDotNet := varDotNet.WrapInt32(1); // Creates an instance of the .NET Framework array that contains the user-defined type. varArray := varArray.CreateInstance(varDotNet.GetType(), arraySize); // Clears the object instance because it is no longer used. clear(varDotNet); // Sets data in the array. FOR i := 0 TO (arraySize -1) DO BEGIN varDotNet := varDotNet.WrapInt32(i+100); varArray.SetValue(varDotNet,i); END; // Gets array data and validates content. FOR i := 0 TO (arraySize -1) DO BEGIN varDotNet := varArray.GetValue(i); // Gets the integer value from the .NET Framework object using the Data property. alData := varDotNEt.Data; if alData <> (i+100) then error('Invalid array data in element %1, expected %2, actual %3', i, i+100, alData); END;
See Also
Extending Microsoft Dynamics NAV Using Microsoft .NET Framework Interoperability