VFP封装结构类型示例（四） [结]

CLEAR
cDefPath = ADDBS(JUSTPATH(SYS(16)))
SET DEFAULT TO (cDefPath)

#INCLUDE apiFuns.h
SET PROCEDURE TO apiFuns.prg, StructClass.prg ADDITIVE
LoadApi()

ds = CREATEOBJECT("数据结构")
ds.create()
dt = CREATEOBJECT("数据表")

bufSize = ds.size
pBuffer = myMalloc(bufSize)

head = 0    && 头记录指针
last = 0    && 尾记录指针

filename = cDefPath + "test.dat"
load_data(filename)
add_data("三姑", 1, 18, 170,     1.1, -1.1)
add_data("六婆", 2, 22, 175,  -22.22, 22.22)
add_data("七婶", 3, 36, 180, 333.333, -333.333)
list_data()
save_data(filename)

SET PROCEDURE TO
CLEAR ALL
RETURN

DEFINE CLASS 数据结构 as STRUCT_CLASS
    PROCEDURE init
        this.stInit("name", "C",10)    && 字符串
        this.stInit("num1", "U",1)     && 无符号整数
        this.stInit("num2", "I",2)     && 有符号整数
        this.stInit("num3", "I",4)
        this.stInit("num4", "F",4)     && 单精度浮点数
        this.stInit("num5", "F",8)     && 双精度浮点数
    ENDPROC
ENDDEFINE

DEFINE CLASS 数据表 as STRUCT_CLASS
    PROCEDURE init(ds)
        this.stInit("数据记录", "C",29)
        this.stInit("next",     "U",4)
    ENDPROC
ENDDEFINE

FUNCTION add_data(name, num1, num2, num3, num4, num5)
    LOCAL ptr
    ptr = dt.create()
    ds.setValue("name", name, ptr)
    ds.setValue("num1", num1, ptr)
    ds.setValue("num2", num2, ptr)
    ds.setValue("num3", num3, ptr)
    ds.setValue("num4", num4, ptr)
    ds.setValue("num5", num5, ptr)
    dt.setValue("next", 0,    ptr)
    IF last != 0
        dt.setValue("next", ptr,  last)
    ENDIF
    IF head == 0
        head = ptr
    ENDIF   
    last = ptr
    RETURN last
ENDFUNC

FUNCTION load_data(filename)
    IF !FILE(filename)
        RETURN 0
    ENDIF
    LOCAL fp, ptr
    fp = myFOpen(filename, "rb")
    IF  fp == 0
        RETURN 0
    ENDIF
    head = 0
    last = 0
    IF apiFRead(pBuffer,bufSize,1,fp) == 1
        head = dt.create()
        apiMemcpy_s(head, bufSize, pBuffer, bufSize)
        dt.setValue("next", 0, head)
        last = head
    ENDIF
    DO WHILE apiFRead(pBuffer,bufSize,1,fp) == 1
        ptr = dt.create()
        apiMemcpy_s(ptr, bufSize, pBuffer, bufSize)
        dt.setValue("next", 0, ptr)
        dt.setValue("next", ptr, last)
        last = ptr
    ENDDO
    apiFClose(fp)
    RETURN head
ENDFUNC

FUNCTION save_data(filename)
    LOCAL fp, ptr
    fp = myFOpen(filename, "wb")
    IF  fp == 0
        RETURN 0
    ENDIF
    ptr = head
    DO WHILE ptr != 0
        apiFWrite(ptr, bufSize, 1, fp)
        ptr = dt.getValue("next", ptr)
    ENDDO
    apiFClose(fp)
    RETURN 1
ENDFUNC

FUNCTION list_data()
    LOCAL ptr
    ?  ds.aSTRUCT[1,1] + "  "
    ?? ds.aSTRUCT[2,1] + "     "
    ?? ds.aSTRUCT[3,1] + "     "
    ?? ds.aSTRUCT[4,1] + "               "
    ?? ds.aSTRUCT[5,1] + "                 "
    ?? ds.aSTRUCT[6,1]
    ptr = head
    DO WHILE ptr != 0
        ?  ds.getValue("name", ptr)
        ?? ds.getValue("num1", ptr)
        ?? ds.getValue("num2", ptr)
        ?? ds.getValue("num3", ptr)
        ?? ROUND(ds.getValue("num4", ptr), 4)
        ?? ROUND(ds.getValue("num5", ptr), 4)
        ptr = dt.getValue("next", ptr)
    ENDDO
ENDFUNC