|
1. shp文件
1. 文件结构
Position
Field
Value
Type
Order
Byte 0
File Code
9994
Integer
Big
Byte 4
Unused
0
Integer
Big
Byte 8
Unused
0
Integer
Big
Byte 12
Unused
0
Integer
Big
Byte 16
Unused
0
Integer
Big
Byte 20
Unused
0
Integer
Big
Byte 24
File Length
File Length
Integer
Big
Byte 28
Version
1000
Integer
Little
Byte 32
Shape Type
Shape Type
Integer
Little
Byte 36
Bounding Box
Xmin
Double
Little
Byte 44
Bounding Box
Ymin
Double
Little
Byte 52
Bounding Box
Xmax
Double
Little
Byte 60
Bounding Box
Ymax
Double
Little
Byte 68*
Bounding Box
Zmin
Double
Little
Byte 76*
Bounding Box
Zmax
Double
Little
Byte 84*
Bounding Box
Mmin
Double
Little
Byte 92*
Bounding Box
Mmax
Double
Little
Unused, with value 0.0, if not Measured or Z type
说明：Big表示大尾（big endian）型字节顺序，即是高低位字节是反序的，主要适用于Sun® or Motorola®平台，而Little表示小尾（little endian）型字节顺序，高低位字节顺序不变，主要使用在PC or Intel®平台。在读取的字节为Big时，需要进行字节顺序交换，才能得出正确的值。
一个把Big顺序转换为Little顺序的函数可以如下：
int Big2LittleEndian(int num)
{
int reverse; //返回结果
char bit0, bit1, bit2, bit3;
bit0 = (num & 0x000000ff);
bit1 = (num & 0x0000ff00) >> 8;
bit2 = (num & 0x00ff0000) >> 16;
bit3 = (num & 0xff000000) >> 24;
reverse = (bit0 |