Application Techniques
Calling .NET Assembly in an Application

The following table lists the data type mappings between PowerBuilder and .NET. Keep in mind that PowerBuilder and .NET data types may not have the same definitions even if the type name is the same or similar. For PowerBuilder data types, refer to the section called “Datatypes” in PowerScript Reference. For .NET data types, refer to the Types and variables web page.

PowerBuilder char maps to .NET string, and PowerBuilder ref char maps to .NET char.

PowerBuilder blob[] maps to .NET byte[][]. PowerBuilder blob two-dimensional array is unsupported.

The index in PowerScript starts from 1, while the index in .NET starts from 0, therefore, PowerBuilder Array[1] maps to .NET Array[0].

When the .NET function is imported to the NVO, the two-dimensional array will be converted to Any data type when passed as arguments or return values, and the first-dimensional array will be converted to Any data type when passed as return values, because PowerBuilder does not support using the array argument as the return value of a function (the developer can use the corresponding array or any to receive the value).

For numeric data type, the mapping between PowerBuilder and .NET can be fuzzy. For example, even the .NET integer-type should be mapped to PowerBuilder long-type normally, the .NET function "public int Add(int parm1, int parm2)" can also be called by the integer-type parameter in PowerBuilder (instead of the long-type parameter).

For standard data type and array data type, PowerBuilder can map to the .NET nullable and non-nullable types, for example, PowerBuilder integer type can map to the .NET short and short? types.

For numeric array, PowerBuilder and .NET must be exactly mapped. For example, PowerBuilder integer-type array can only map to the .NET short-type array.

Date and Time can only be used in arguments and cannot be used in return values; when used in arguments, they are passed to .NET as DateTime; when passed by Ref, the value will be sync to the Date and Time variables; they cannot be used as return values to receive DateTime return values from .NET; and cannot set or receive DateTime property values from .NET.

When passing a PowerBuilder variable-length array to .NET, .NET can use list to process the data from the PowerBuilder variable-length array, and then assign the data to the PowerBuilder ref variable-length array or return the data directly. At the end of this section, there is a sample of PowerScript code that uses the variable-length array to receive the double-type data from .NET.

Supported return value data types

The following table lists the return value data type mappings between PowerBuilder and .NET.

.NET classes are supported, except for the following:

Nested class is supported, except that using the plus sign (“+”) instead of the dot (“.”) to access the nested class: [namespace].[class]+[nested-class].

.NET functions are supported, except for the following:

Function parameters and return values are supported with the following exceptions:

The return object will be auto-instantiated as a DotNetObject object; users do not need to create it, but can destroy it when it is no longer used.

The return object cannot be used directly as a parameter by reference; users will need to receive the return object first, and then use it as a parameter. For example,

This statement is unsupported:

ls_ret = lnv_TestCLR1.TestReferenceObj (ref lnv_TestCLR1.TestReturnObj())

This statement is supported:

//lnv_ReturnObj is auto-instantiated
lnv_ReturnObj = lnv_TestCLR1.TestReturnObj()
ls_ret = lnv_TestCLR1.TestReferenceObj (ref lnv_ReturnObj)

The generic type, delegate, interface, or class (including abstract class) will be converted to DotNetObject when used as the parameter.

The generic type, delegate, interface, or class (including abstract class) can be passed by reference when used as the parameter.

Each property will have two functions imported (one for getting the property value and the other for setting). Read-only or write-only property will have only one function imported.

Getting or setting a property is supported, except for the following:

Data fields are unsupported.

Transaction Objects (specifically IAdoConnectionProxy) are only supported in .NET Framework, but not in .NET and .NET Core.

Transaction Objects from .NET do not support Oracle Data Provider for .NET (Oracle.DataAccess.Client or Oracle.ManagedDataAccess.Client).