This final array article in this series is a specialized tip, but when needed it is very handy to have available.
In AVR Classic you could use data structures to overlay incoming values from a disk file record buffer into other values, structures, or arrays. Overlapping array techniques with packed and binary data is troublesome in .NET (because .NET doesn’t have the concept of field values being mapped contiguously in memory like AVR Classic and green-screen RPG do). The DclAliasGroup operation helps to remove the pain of mapping an incoming record buffer to an array.
For example, consider the following record format. It has twelve monthly account balance values in fields CSSales01 through CSSales12. When this record is read, you want to implicitly map these 12 record format fields into an array.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 |
-------------------------------------------------------------------------------- CSMasterL1 file layout. -------------------------------------------------------------------------------- Database name... DG Net Local Library name.... Examples File name....... CSMasterL1 -------------------------------------------------------------------------------- CSCustNo *Packed Len( 9, 0) Cutomer Number CSYear *Zoned Len( 4, 0) Sales Year CSType *Zoned Len( 1, 0) 1 = sales 2 = returns CSSales01 *Packed Len( 11, 2) Sales Month 01 CSSales02 *Packed Len( 11, 2) Sales Month 02 CSSales03 *Packed Len( 11, 2) Sales Month 03 CSSales04 *Packed Len( 11, 2) Sales Month 04 CSSales05 *Packed Len( 11, 2) Sales Month 05 CSSales06 *Packed Len( 11, 2) Sales Month 06 CSSales07 *Packed Len( 11, 2) Sales Month 07 CSSales08 *Packed Len( 11, 2) Sales Month 08 CSSales09 *Packed Len( 11, 2) Sales Month 09 CSSales10 *Packed Len( 11, 2) Sales Month 10 CSSales11 *Packed Len( 11, 2) Sales Month 11 CSSales12 *Packed Len( 11, 2) Sales Month 12 |
The array below is the target array into which we want to put each of the twelve monthly fields:
|
1 2 3 |
DclArray MonthlyTotals Type(*Packed) + Len(11, 2) + Dim(12) |
This line of AVR for .NET (defined in the code right after the DclArray) causes the automatic mapping of the fields into the array—implicitly each time a record is read:
|
1 2 3 4 |
DclAliasGroup MonthlyTotals + Flds(SalesDtls_CSSales01) + Fmt(SALESFORMAT) + Count(12) |
With the target array and the DclAliasGroup declared, the twelve monthly balance fields are moved implicitly into the MonthlyTotals array after the record format is read. After a read operation, fields CSSales01 through CSSales12 values are in MonthlyTotal's elements 0 through 11, respectively.
