如何将4个字节的int转为1个字节的BYTE?

int i=0x00000001;
要取得最后一个字节的0x01?
BYTE ret;
BYTE *ptr;

ptr=(BYTE*)(&i);

ret=*ptr; //小端内存

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以下内容为转载

x的高字节存放到x_high,把低字节x_low

int x=12345;

unsigned
char x_low;

unsigned
char x_high;

unsigned
char
*ptr;

ptr=(unsigned
char*)(&x)；

//小端内存

x_low
=
*ptr;

x_high
=
*(ptr+(sizeof(int)-1));

//大端内存

x_high
=
*ptr;

x_low
=
*(ptr+(sizeof(int)-1));