我有#include <stdio.h>
#include <stddef.h>
#include <limits.h>
#if CHAR_BIT != 8
#error "unsupported char size"
#endif
int isLittleEndian ()
{
static const int num = 1;
if (1 == *((char *) &num))
{
return 1;
}
else
{
return 0;
}
}
char * getBinaryHostMemoryRepresentation (char * const buffer, size_t bufSize, const void * var, size_t varSize)
{
size_t byteIdx;
size_t bitIdx;
if (bufSize < varSize * CHAR_BIT + 1)
{
return NULL;
}
const unsigned char * curByte = (const unsigned char *) var;
for (byteIdx = 0; byteIdx < varSize; ++byteIdx, ++curByte)
{
for (bitIdx = 0; bitIdx < CHAR_BIT; ++bitIdx)
{
unsigned char curBit = (*curByte & (1 << ((CHAR_BIT - 1) - bitIdx))) >> ((CHAR_BIT - 1) - bitIdx);
buffer[byteIdx * CHAR_BIT + bitIdx] = curBit + '0';
}
}
buffer[varSize * CHAR_BIT] = '\0';
return buffer;
}
char * getBinaryRepresentation (char * const buffer, size_t bufSize, const void * var, size_t varSize)
{
size_t byteIdx;
size_t bitIdx;
if (bufSize < varSize * CHAR_BIT + 1)
{
return NULL;
}
const unsigned char * curByte;;
int incByte;
if (isLittleEndian ())
{
curByte = (const unsigned char *) var + (varSize - 1);
incByte = -1;
}
else
{
curByte = (const unsigned char *) var;
incByte = 1;
}
for (byteIdx = 0; byteIdx < varSize; ++byteIdx, curByte += incByte)
{
for (bitIdx = 0; bitIdx < CHAR_BIT; ++bitIdx)
{
unsigned char curBit = (*curByte & (1 << ((CHAR_BIT - 1) - bitIdx))) >> ((CHAR_BIT - 1) - bitIdx);
buffer[byteIdx * CHAR_BIT + bitIdx] = curBit + '0';
}
}
buffer[varSize * CHAR_BIT] = '\0';
return buffer;
}
int main ()
{
int integer = 2882400235; /* 10101011110011011110111111101011 */
char bufferMemInt[sizeof (integer) * CHAR_BIT + 1];
char bufferBinInt[sizeof (integer) * CHAR_BIT + 1];
printf ("integer 2882400235:\n");
if (getBinaryHostMemoryRepresentation (bufferMemInt,
sizeof (bufferMemInt),
(void *) &integer,
sizeof (integer)))
{
printf ("Host memory binary representation: \"%s\"",
bufferMemInt);
printf ("\n");
}
if (getBinaryRepresentation (bufferBinInt,
sizeof (bufferBinInt),
(void *) &integer,
sizeof (integer)))
{
printf ("Human readable binary representation: \"%s\"",
bufferBinInt);
printf ("\n");
}
float floating = 42.0; /* 01000010001010000000000000000000 */
char bufferMemFloat[sizeof (floating) * CHAR_BIT + 1];
char bufferBinFloat[sizeof (floating) * CHAR_BIT + 1];
printf ("\n");
printf ("single floating point 42.0:\n");
if (getBinaryHostMemoryRepresentation (bufferMemFloat,
sizeof (bufferMemFloat),
(void *) &floating,
sizeof (floating)))
{
printf ("Host memory binary representation: \"%s\"",
bufferMemFloat);
printf ("\n");
}
if (getBinaryRepresentation (bufferBinFloat,
sizeof (bufferBinFloat),
(void *) &floating,
sizeof (floating)))
{
printf ("Human readable binary representation: \"%s\"",
bufferBinFloat);
printf ("\n");
}
return 0;
}
，其中包含许多Ad
AdPhoto它可以直接删除AdPhoto（删除db记录和文件）：
// Ad model
public function ad_photos() {
return $this->hasMany('App\AdPhoto')->orderBy('position', 'desc');
}
// AdPhoto model
public static function boot() {
parent::boot();
AdPhoto::deleting(function($photo) {
\File::delete(public_path('photos').'/'.$photo['filename']);
}
}
它无法删除广告（不删除文件，只删除数据库记录）：
\App\AdPhoto::find($id)->delete();
如何让它发挥作用？
（Laravel 5.4）
答案 0 :(得分：0)
您可以在AdPhoto::deletePhotos($adId);
模型中创建方法并使用它而不是使用事件：
public static function deletePhotos($adId)
{
$photos = this->where('ad_id', $adId)->get();
foreach ($photos as $photo) {
\File::delete(public_path('photos').'/'.$photo['filename']);
}
return $this->destroy($photos->pluck('id')->toArray());
}
方法示例：
<XRF r="9.0.2" c="iD2" g="" u="SG31378-narnapid01" k="969232067"
d="20170613" t="111536">
<IL k="1">
<I k="86103141,812,333">
<M k="6" b="62409" c="333"/>
<M k="186" b="62409" v="543014"/>
<P k="3,1,1" s="1" td="10" v="9617.5" t="190350" d="20170613" z="1" n="273"
b="635"/>
<P k="33,537,1" s="1" td="10" v="-14" t="190350" d="20170613" z="1" n="273"
b="635"/>
<P k="33,579,1" s="1" td="10" v="-0.145356" t="190350" d="20170613" n="273"
b="635"/>
<P k="12,0,1" vt="1" s="1" td="10" v="9617.5" t="190350" d="20170613" z="1"
n="273" b="635"/>
</I>
答案 1 :(得分：0)
尝试创建Event Observer以收听删除事件。
所以你的AdPhoto观察者会有这个函数来处理删除。
public function deleting(\App\AdPhoto $photo)
{
// remove from storage here
\File::delete(public_path('photos').'/'.$photo->filename);
}
答案 2 :(得分：0)
解决了这个问题：
foreach($ad->ad_photos()->get() as $photo) {
$photo->delete();
}