[英]LVITEM for windows 64 bit
很長時間以來,我嘗試將LVM_GETITEMW
消息與LVIF_TEXT
掩碼一起使用以獲取ListView的文本。 我的程序在32位上工作,但在64位體系結構上工作。
我發現問題出在LVITEM
結構上。 不久,我的問題是哪種結構適合64位,為什么呢?
我用作LVITEMW
結構的結構具有以下字段:
('mask', c_uint32),
('iItem', c_int32),
('iSubItem', c_int32),
('state', c_uint32),
('stateMask', c_uint32),
('pszText', c_uint32),
('cchTextMax', c_int32),
('iImage', c_int32),
('lParam', c_uint64),
('iIndent', c_int32),
('iGroupId', c_int32),
('cColumns', c_uint32),
('puColumns', c_uint32),
('piColFmt', c_int32),
('iGroup', c_int32)
(使用python 2.7 ctypes編寫,但這只是一種書寫形式-語言確實無關緊要)。
這些字段已記錄 。
經過大量的搜尋,我發現這個論壇正是我所需要的-64位解決方案!
因此,在64位中,該結構應該具有更多的“空間”,並且應該看起來像這樣(指針現在為64位, stateMask
也為64位。這與論壇建議的內容略有不同,但也可以使用):
('mask', c_uint32),
('iItem', c_int32),
('iSubItem', c_int32),
('state', c_uint32),
('stateMask', c_uint64), <-- Now 64 bit
('pszText', c_uint64), <-- Now 64 bit which makes sense since this is a pointer
('cchTextMax', c_int32),
('iImage', c_int32),
('lParam', c_uint64),
('iIndent', c_int32),
('iGroupId', c_int32),
('cColumns', c_uint32),
('puColumns', c_uint64), <-- Now 64 bit which makes sense since this is a pointer
('piColFmt', c_int64), <-- Now 64 bit which makes sense since this is a pointer
('iGroup', c_int32)
該論壇建議:
('mask', c_uint32),
('iItem', c_int32),
('iSubItem', c_int32),
('state', c_uint32),
('stateMask', c_uint64),
('pszText', c_uint64),
('cchTextMax', c_int32),
('iImage', c_int64), <-- Now 64 bit
('lParam', c_uint32),
('iIndent', c_int32),
('iGroupId', c_int32),
('cColumns', c_uint32),
('puColumns', c_uint32),
('piColFmt', c_int32),
('iGroup', c_int64), <-- Now 128 bit all together
('iGroup2', c_int64) <-- continuation
pszText指向的文本也可以用,在我需要的列表中。
我的問題是:
stateMask
是c_uint64
-它不應該永遠是大小相同的state
? 謝謝!
感謝Raymond Chen的評論,我得以弄清楚答案!
這與數據對齊有關 。 每個指針應為8個字節,並且還應對齊可除以8的地址,因此有時指針前應有填充。 另外,該結構的大小應可除以min(max(sizeof(each field in the struct)), 8)
,在本例中為8,因為指針的大小為8。
class LVITEMW_explicit(ctypes.Structure):
_pack_ = 1
_fields_ = [
('mask', c_uint32), # 0
('iItem', c_int32), # 4
('iSubItem', c_int32), # 8
('state', c_uint32), # 12
('stateMask', c_uint32), # 16
('padding1', c_int),
('pszText', c_uint64), # 20 --> 24 after padding (A pointer)
('cchTextMax', c_int32), # 32
('iImage', c_int32), # 36
('lParam', c_uint64), # 40 (On 32 bit should be c_long which is 32 bits)
('iIndent', c_int32), # 48
('iGroupId', c_int32), # 52
('cColumns', c_uint32), # 56
('padding2', c_int),
('puColumns', c_uint64), # 60 --> 64 after padding (A pointer)
('piColFmt', c_int64), # 72 (A pointer)
('iGroup', c_int32), # 80
('padding3', c_int32), # The total length was 84 before padding3 was added, which is not dividable by 8
]
還是應該這樣寫-沒有_pack_ = 1
:
class LVITEMW(ctypes.Structure):
_fields_ = [
('mask', c_uint32),
('iItem', c_int32),
('iSubItem', c_int32),
('state', c_uint32),
('stateMask', c_uint32),
('pszText', c_uint64),
('cchTextMax', c_int32),
('iImage', c_int32),
('lParam', c_uint64), # On 32 bit should be c_long
('iIndent', c_int32),
('iGroupId', c_int32),
('cColumns', c_uint32),
('puColumns', c_uint64),
('piColFmt', c_int64),
('iGroup', c_int32),
]
實際上, ctypes.sizeof(LVITEMW)
返回88,與ctypes.sizeof(LVITEMW_explicit)
相同。
再次感謝您的有用評論!
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