第一次遇到WKID是遥远的大三,学WebGIS写Flex时, WKID的英文全称是Well Known ID,即众所周知的编号。这个编号是大家坐下来一起讨论、约定和认同的,具体有唯一性。众多的坐标系统有了自己的WKID,就像每个人都有自己的身份证号一样,从出生就定了,即使是名字改了,还是可 能通过身份证号确定,这为空间数据的使用、转换、共享等起到关键作用。
坐标系统的WKID示例:
WKID |
4508 |
名称 |
CGCS2000_GK_CM_111E |
参数 |
PROJCS["CGCS2000_GK_CM_111E",GEOGCS["GCS_China_Geodetic_Coordinate_System_2000",DATUM["D_China_2000",SPHEROID["CGCS2000",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Gauss_Kruger"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",111.0],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]] |
二、使用方法
提到坐标,要注意两个版本上的区别:
(1)在Desktop10.0及以前的版本中,坐标文件是以prj文件存在的;自10.1版本起,坐标文件存储在projection engine library (pe.dll)中,从而可以提高读取效率;
(2)我们常用的CGCS2000在10.0中只有地理坐标文件,没有投影坐标文件,如果要使用,则需制作及收藏。
在AE中将地理坐标投影后求长度(或平面坐标,或面积)的示例代码如下:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
|
/// <summary>
/// 获取投影长度
/// </summary>
/// <param name="pGeometry">几何图层</param>
/// <returns>长度(米)</returns>
public
static
double
GetLengh(IGeometry pGeometry)
{
ISpatialReferenceFactory srFactory =
new
SpatialReferenceEnvironmentClass();
//4508:CGCS2000_GK_CM_111E
ISpatialReference pSpatialReference = srFactory.CreateProjectedCoordinateSystem(4508);
pGeometry.Project(pSpatialReference);
IPolyline polyline = pGeometry
as
IPolyline;
if
(polyline !=
null
)
return
polyline.Length;
else
return
0;
}
|
三、查询方式
WKID这么种,要用的时候去哪里查?这提供三个 位置:
1.ESRI官网
ArcGIS REST API版本
javascript版本
https://developers.arcgis.com/javascript/3/jshelp/gcs.htm
https://developers.arcgis.com/javascript/3/jshelp/pcs.htm
9.3版本:9.3版本没有CGS2000,所以要不去这里查了。
http://resources.esri.com/help/9.3/arcgisserver/apis/rest/gcs.html
http://resources.esri.com/help/9.3/arcgisserver/apis/rest/pcs.html
2.其他网站
http://spatialreference.org/ref/
3.开发文档
在官方SDK帮助文档可以查到枚举类型,例如投影坐标枚举esriSRProjCSType包含1442个WKID,esriSRProjCS4Type包含1224个WKID.
4.本文
本人整理了将官网的整理Excel方便查询,下面附表是其中中国常用的坐标系统及WKID
参考
https://geonet.esri.com/thread/10174
http://blog.csdn.net/kikitamoon/article/details/8833000
附表
下面是我国常用的地理和投影坐标系的WKID:
类别 |
WKID |
名称 |
地理坐标 |
4214 |
GCS_Beijing_1954 |
地理坐标 |
4326 |
GCS_WGS_1984 |
地理坐标 |
4490 |
GCS_China_Geodetic_Coordinate_System_2000 |
地理坐标 |
4555 |
GCS_New_Beijing |
地理坐标 |
4610 |
GCS_Xian_1980 |
投影坐标 |
2327 |
Xian_1980_GK_Zone_13 |
投影坐标 |
2328 |
Xian_1980_GK_Zone_14 |
投影坐标 |
2329 |
Xian_1980_GK_Zone_15 |
投影坐标 |
2330 |
Xian_1980_GK_Zone_16 |
投影坐标 |
2331 |
Xian_1980_GK_Zone_17 |
投影坐标 |
2332 |
Xian_1980_GK_Zone_18 |
投影坐标 |
2333 |
Xian_1980_GK_Zone_19 |
投影坐标 |
2334 |
Xian_1980_GK_Zone_20 |
投影坐标 |
2335 |
Xian_1980_GK_Zone_21 |
投影坐标 |
2336 |
Xian_1980_GK_Zone_22 |
投影坐标 |
2337 |
Xian_1980_GK_Zone_23 |
投影坐标 |
2338 |
Xian_1980_GK_CM_75E |
投影坐标 |
2339 |
Xian_1980_GK_CM_81E |
投影坐标 |
2340 |
Xian_1980_GK_CM_87E |
投影坐标 |
2341 |
Xian_1980_GK_CM_93E |
投影坐标 |
2342 |
Xian_1980_GK_CM_99E |
投影坐标 |
2343 |
Xian_1980_GK_CM_105E |
投影坐标 |
2344 |
Xian_1980_GK_CM_111E |
投影坐标 |
2345 |
Xian_1980_GK_CM_117E |
投影坐标 |
2346 |
Xian_1980_GK_CM_123E |
投影坐标 |
2347 |
Xian_1980_GK_CM_129E |
投影坐标 |
2348 |
Xian_1980_GK_CM_135E |
投影坐标 |
2349 |
Xian_1980_3_Degree_GK_Zone_25 |
投影坐标 |
2350 |
Xian_1980_3_Degree_GK_Zone_26 |
投影坐标 |
2351 |
Xian_1980_3_Degree_GK_Zone_27 |
投影坐标 |
2352 |
Xian_1980_3_Degree_GK_Zone_28 |
投影坐标 |
2353 |
Xian_1980_3_Degree_GK_Zone_29 |
投影坐标 |
2354 |
Xian_1980_3_Degree_GK_Zone_30 |
投影坐标 |
2355 |
Xian_1980_3_Degree_GK_Zone_31 |
投影坐标 |
2356 |
Xian_1980_3_Degree_GK_Zone_32 |
投影坐标 |
2357 |
Xian_1980_3_Degree_GK_Zone_33 |
投影坐标 |
2358 |
Xian_1980_3_Degree_GK_Zone_34 |
投影坐标 |
2359 |
Xian_1980_3_Degree_GK_Zone_35 |
投影坐标 |
2360 |
Xian_1980_3_Degree_GK_Zone_36 |
投影坐标 |
2361 |
Xian_1980_3_Degree_GK_Zone_37 |
投影坐标 |
2362 |
Xian_1980_3_Degree_GK_Zone_38 |
投影坐标 |
2363 |
Xian_1980_3_Degree_GK_Zone_39 |
投影坐标 |
2364 |
Xian_1980_3_Degree_GK_Zone_40 |
投影坐标 |
2365 |
Xian_1980_3_Degree_GK_Zone_41 |
投影坐标 |
2366 |
Xian_1980_3_Degree_GK_Zone_42 |
投影坐标 |
2367 |
Xian_1980_3_Degree_GK_Zone_43 |
投影坐标 |
2368 |
Xian_1980_3_Degree_GK_Zone_44 |
投影坐标 |
2369 |
Xian_1980_3_Degree_GK_Zone_45 |
投影坐标 |
2370 |
Xian_1980_3_Degree_GK_CM_75E |
投影坐标 |
2371 |
Xian_1980_3_Degree_GK_CM_78E |
投影坐标 |
2372 |
Xian_1980_3_Degree_GK_CM_81E |
投影坐标 |
2373 |
Xian_1980_3_Degree_GK_CM_84E |
投影坐标 |
2374 |
Xian_1980_3_Degree_GK_CM_87E |
投影坐标 |
2375 |
Xian_1980_3_Degree_GK_CM_90E |
投影坐标 |
2376 |
Xian_1980_3_Degree_GK_CM_93E |
投影坐标 |
2377 |
Xian_1980_3_Degree_GK_CM_96E |
投影坐标 |
2378 |
Xian_1980_3_Degree_GK_CM_99E |
投影坐标 |
2379 |
Xian_1980_3_Degree_GK_CM_102E |
投影坐标 |
2380 |
Xian_1980_3_Degree_GK_CM_105E |
投影坐标 |
2381 |
Xian_1980_3_Degree_GK_CM_108E |
投影坐标 |
2382 |
Xian_1980_3_Degree_GK_CM_111E |
投影坐标 |
2383 |
Xian_1980_3_Degree_GK_CM_114E |
投影坐标 |
2384 |
Xian_1980_3_Degree_GK_CM_117E |
投影坐标 |
2385 |
Xian_1980_3_Degree_GK_CM_120E |
投影坐标 |
2386 |
Xian_1980_3_Degree_GK_CM_123E |
投影坐标 |
2387 |
Xian_1980_3_Degree_GK_CM_126E |
投影坐标 |
2388 |
Xian_1980_3_Degree_GK_CM_129E |
投影坐标 |
2389 |
Xian_1980_3_Degree_GK_CM_132E |
投影坐标 |
2390 |
Xian_1980_3_Degree_GK_CM_135E |
投影坐标 |
2401 |
Beijing_1954_3_Degree_GK_Zone_25 |
投影坐标 |
2402 |
Beijing_1954_3_Degree_GK_Zone_26 |
投影坐标 |
2403 |
Beijing_1954_3_Degree_GK_Zone_27 |
投影坐标 |
2404 |
Beijing_1954_3_Degree_GK_Zone_28 |
投影坐标 |
2405 |
Beijing_1954_3_Degree_GK_Zone_29 |
投影坐标 |
2406 |
Beijing_1954_3_Degree_GK_Zone_30 |
投影坐标 |
2407 |
Beijing_1954_3_Degree_GK_Zone_31 |
投影坐标 |
2408 |
Beijing_1954_3_Degree_GK_Zone_32 |
投影坐标 |
2409 |
Beijing_1954_3_Degree_GK_Zone_33 |
投影坐标 |
2410 |
Beijing_1954_3_Degree_GK_Zone_34 |
投影坐标 |
2411 |
Beijing_1954_3_Degree_GK_Zone_35 |
投影坐标 |
2412 |
Beijing_1954_3_Degree_GK_Zone_36 |
投影坐标 |
2413 |
Beijing_1954_3_Degree_GK_Zone_37 |
投影坐标 |
2414 |
Beijing_1954_3_Degree_GK_Zone_38 |
投影坐标 |
2415 |
Beijing_1954_3_Degree_GK_Zone_39 |
投影坐标 |
2416 |
Beijing_1954_3_Degree_GK_Zone_40 |
投影坐标 |
2417 |
Beijing_1954_3_Degree_GK_Zone_41 |
投影坐标 |
2418 |
Beijing_1954_3_Degree_GK_Zone_42 |
投影坐标 |
2419 |
Beijing_1954_3_Degree_GK_Zone_43 |
投影坐标 |
2420 |
Beijing_1954_3_Degree_GK_Zone_44 |
投影坐标 |
2421 |
Beijing_1954_3_Degree_GK_Zone_45 |
投影坐标 |
2422 |
Beijing_1954_3_Degree_GK_CM_75E |
投影坐标 |
2423 |
Beijing_1954_3_Degree_GK_CM_78E |
投影坐标 |
2424 |
Beijing_1954_3_Degree_GK_CM_81E |
投影坐标 |
2425 |
Beijing_1954_3_Degree_GK_CM_84E |
投影坐标 |
2426 |
Beijing_1954_3_Degree_GK_CM_87E |
投影坐标 |
2427 |
Beijing_1954_3_Degree_GK_CM_90E |
投影坐标 |
2428 |
Beijing_1954_3_Degree_GK_CM_93E |
投影坐标 |
2429 |
Beijing_1954_3_Degree_GK_CM_96E |
投影坐标 |
2430 |
Beijing_1954_3_Degree_GK_CM_99E |
投影坐标 |
2431 |
Beijing_1954_3_Degree_GK_CM_102E |
投影坐标 |
2432 |
Beijing_1954_3_Degree_GK_CM_105E |
投影坐标 |
2433 |
Beijing_1954_3_Degree_GK_CM_108E |
投影坐标 |
2434 |
Beijing_1954_3_Degree_GK_CM_111E |
投影坐标 |
2435 |
Beijing_1954_3_Degree_GK_CM_114E |
投影坐标 |
2436 |
Beijing_1954_3_Degree_GK_CM_117E |
投影坐标 |
2437 |
Beijing_1954_3_Degree_GK_CM_120E |
投影坐标 |
2438 |
Beijing_1954_3_Degree_GK_CM_123E |
投影坐标 |
2439 |
Beijing_1954_3_Degree_GK_CM_126E |
投影坐标 |
2440 |
Beijing_1954_3_Degree_GK_CM_129E |
投影坐标 |
2441 |
Beijing_1954_3_Degree_GK_CM_132E |
投影坐标 |
2442 |
Beijing_1954_3_Degree_GK_CM_135E |
投影坐标 |
3395 |
WGS_1984_World_Mercator |
投影坐标 |
4491 |
CGCS2000_GK_Zone_13 |
投影坐标 |
4492 |
CGCS2000_GK_Zone_14 |
投影坐标 |
4493 |
CGCS2000_GK_Zone_15 |
投影坐标 |
4494 |
CGCS2000_GK_Zone_16 |
投影坐标 |
4495 |
CGCS2000_GK_Zone_17 |
投影坐标 |
4496 |
CGCS2000_GK_Zone_18 |
投影坐标 |
4497 |
CGCS2000_GK_Zone_19 |
投影坐标 |
4498 |
CGCS2000_GK_Zone_20 |
投影坐标 |
4499 |
CGCS2000_GK_Zone_21 |
投影坐标 |
4500 |
CGCS2000_GK_Zone_22 |
投影坐标 |
4501 |
CGCS2000_GK_Zone_23 |
投影坐标 |
4502 |
CGCS2000_GK_CM_75E |
投影坐标 |
4503 |
CGCS2000_GK_CM_81E |
投影坐标 |
4504 |
CGCS2000_GK_CM_87E |
投影坐标 |
4505 |
CGCS2000_GK_CM_93E |
投影坐标 |
4506 |
CGCS2000_GK_CM_99E |
投影坐标 |
4507 |
CGCS2000_GK_CM_105E |
投影坐标 |
4508 |
CGCS2000_GK_CM_111E |
投影坐标 |
4509 |
CGCS2000_GK_CM_117E |
投影坐标 |
4510 |
CGCS2000_GK_CM_123E |
投影坐标 |
4511 |
CGCS2000_GK_CM_129E |
投影坐标 |
4512 |
CGCS2000_GK_CM_135E |
投影坐标 |
4513 |
CGCS2000_3_Degree_GK_Zone_25 |
投影坐标 |
4514 |
CGCS2000_3_Degree_GK_Zone_26 |
投影坐标 |
4515 |
CGCS2000_3_Degree_GK_Zone_27 |
投影坐标 |
4516 |
CGCS2000_3_Degree_GK_Zone_28 |
投影坐标 |
4517 |
CGCS2000_3_Degree_GK_Zone_29 |
投影坐标 |
4518 |
CGCS2000_3_Degree_GK_Zone_30 |
投影坐标 |
4519 |
CGCS2000_3_Degree_GK_Zone_31 |
投影坐标 |
4520 |
CGCS2000_3_Degree_GK_Zone_32 |
投影坐标 |
4521 |
CGCS2000_3_Degree_GK_Zone_33 |
投影坐标 |
4522 |
CGCS2000_3_Degree_GK_Zone_34 |
投影坐标 |
4523 |
CGCS2000_3_Degree_GK_Zone_35 |
投影坐标 |
4524 |
CGCS2000_3_Degree_GK_Zone_36 |
投影坐标 |
4525 |
CGCS2000_3_Degree_GK_Zone_37 |
投影坐标 |
4526 |
CGCS2000_3_Degree_GK_Zone_38 |
投影坐标 |
4527 |
CGCS2000_3_Degree_GK_Zone_39 |
投影坐标 |
4528 |
CGCS2000_3_Degree_GK_Zone_40 |
投影坐标 |
4529 |
CGCS2000_3_Degree_GK_Zone_41 |
投影坐标 |
4530 |
CGCS2000_3_Degree_GK_Zone_42 |
投影坐标 |
4531 |
CGCS2000_3_Degree_GK_Zone_43 |
投影坐标 |
4532 |
CGCS2000_3_Degree_GK_Zone_44 |
投影坐标 |
4533 |
CGCS2000_3_Degree_GK_Zone_45 |
投影坐标 |
4534 |
CGCS2000_3_Degree_GK_CM_75E |
投影坐标 |
4535 |
CGCS2000_3_Degree_GK_CM_78E |
投影坐标 |
4536 |
CGCS2000_3_Degree_GK_CM_81E |
投影坐标 |
4537 |
CGCS2000_3_Degree_GK_CM_84E |
投影坐标 |
4538 |
CGCS2000_3_Degree_GK_CM_87E |
投影坐标 |
4539 |
CGCS2000_3_Degree_GK_CM_90E |
投影坐标 |
4540 |
CGCS2000_3_Degree_GK_CM_93E |
投影坐标 |
4541 |
CGCS2000_3_Degree_GK_CM_96E |
投影坐标 |
4542 |
CGCS2000_3_Degree_GK_CM_99E |
投影坐标 |
4543 |
CGCS2000_3_Degree_GK_CM_102E |
投影坐标 |
4544 |
CGCS2000_3_Degree_GK_CM_105E |
投影坐标 |
4545 |
CGCS2000_3_Degree_GK_CM_108E |
投影坐标 |
4546 |
CGCS2000_3_Degree_GK_CM_111E |
投影坐标 |
4547 |
CGCS2000_3_Degree_GK_CM_114E |
投影坐标 |
4548 |
CGCS2000_3_Degree_GK_CM_117E |
投影坐标 |
4549 |
CGCS2000_3_Degree_GK_CM_120E |
投影坐标 |
4550 |
CGCS2000_3_Degree_GK_CM_123E |
投影坐标 |
4551 |
CGCS2000_3_Degree_GK_CM_126E |
投影坐标 |
4552 |
CGCS2000_3_Degree_GK_CM_129E |
投影坐标 |
4553 |
CGCS2000_3_Degree_GK_CM_132E |
投影坐标 |
4554 |
CGCS2000_3_Degree_GK_CM_135E |
投影坐标 |
4568 |
New_Beijing_Gauss_Kruger_Zone_13 |
投影坐标 |
4569 |
New_Beijing_Gauss_Kruger_Zone_14 |
投影坐标 |
4570 |
New_Beijing_Gauss_Kruger_Zone_15 |
投影坐标 |
4571 |
New_Beijing_Gauss_Kruger_Zone_16 |
投影坐标 |
4572 |
New_Beijing_Gauss_Kruger_Zone_17 |
投影坐标 |
4573 |
New_Beijing_Gauss_Kruger_Zone_18 |
投影坐标 |
4574 |
New_Beijing_Gauss_Kruger_Zone_19 |
投影坐标 |
4575 |
New_Beijing_Gauss_Kruger_Zone_20 |
投影坐标 |
4576 |
New_Beijing_Gauss_Kruger_Zone_21 |
投影坐标 |
4577 |
New_Beijing_Gauss_Kruger_Zone_22 |
投影坐标 |
4578 |
New_Beijing_Gauss_Kruger_Zone_23 |
投影坐标 |
4579 |
New_Beijing_Gauss_Kruger_CM_75E |
投影坐标 |
4580 |
New_Beijing_Gauss_Kruger_CM_81E |
投影坐标 |
4581 |
New_Beijing_Gauss_Kruger_CM_87E |
投影坐标 |
4582 |
New_Beijing_Gauss_Kruger_CM_93E |
投影坐标 |
4583 |
New_Beijing_Gauss_Kruger_CM_99E |
投影坐标 |
4584 |
New_Beijing_Gauss_Kruger_CM_105E |
投影坐标 |
4585 |
New_Beijing_Gauss_Kruger_CM_111E |
投影坐标 |
4586 |
New_Beijing_Gauss_Kruger_CM_117E |
投影坐标 |
4587 |
New_Beijing_Gauss_Kruger_CM_123E |
投影坐标 |
4588 |
New_Beijing_Gauss_Kruger_CM_129E |
投影坐标 |
4589 |
New_Beijing_Gauss_Kruger_CM_135E |
投影坐标 |
4652 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_25 |
投影坐标 |
4653 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_26 |
投影坐标 |
4654 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_27 |
投影坐标 |
4655 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_28 |
投影坐标 |
4656 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_29 |
投影坐标 |
4766 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_30 |
投影坐标 |
4767 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_31 |
投影坐标 |
4768 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_32 |
投影坐标 |
4769 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_33 |
投影坐标 |
4770 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_34 |
投影坐标 |
4771 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_35 |
投影坐标 |
4772 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_36 |
投影坐标 |
4773 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_37 |
投影坐标 |
4774 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_38 |
投影坐标 |
4775 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_39 |
投影坐标 |
4776 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_40 |
投影坐标 |
4777 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_41 |
投影坐标 |
4778 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_42 |
投影坐标 |
4779 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_43 |
投影坐标 |
4780 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_44 |
投影坐标 |
4781 |
New_Beijing_3_Degree_Gauss_Kruger_Zone_45 |
投影坐标 |
4782 |
New_Beijing_3_Degree_Gauss_Kruger_CM_75E |
投影坐标 |
4783 |
New_Beijing_3_Degree_Gauss_Kruger_CM_78E |
投影坐标 |
4784 |
New_Beijing_3_Degree_Gauss_Kruger_CM_81E |
投影坐标 |
4785 |
New_Beijing_3_Degree_Gauss_Kruger_CM_84E |
投影坐标 |
4786 |
New_Beijing_3_Degree_Gauss_Kruger_CM_87E |
投影坐标 |
4787 |
New_Beijing_3_Degree_Gauss_Kruger_CM_90E |
投影坐标 |
4788 |
New_Beijing_3_Degree_Gauss_Kruger_CM_93E |
投影坐标 |
4789 |
New_Beijing_3_Degree_Gauss_Kruger_CM_96E |
投影坐标 |
4790 |
New_Beijing_3_Degree_Gauss_Kruger_CM_99E |
投影坐标 |
4791 |
New_Beijing_3_Degree_Gauss_Kruger_CM_102E |
投影坐标 |
4792 |
New_Beijing_3_Degree_Gauss_Kruger_CM_105E |
投影坐标 |
4793 |
New_Beijing_3_Degree_Gauss_Kruger_CM_108E |
投影坐标 |
4794 |
New_Beijing_3_Degree_Gauss_Kruger_CM_111E |
投影坐标 |
4795 |
New_Beijing_3_Degree_Gauss_Kruger_CM_114E |
投影坐标 |
4796 |
New_Beijing_3_Degree_Gauss_Kruger_CM_117E |
投影坐标 |
4797 |
New_Beijing_3_Degree_Gauss_Kruger_CM_120E |
投影坐标 |
4798 |
New_Beijing_3_Degree_Gauss_Kruger_CM_123E |
投影坐标 |
4799 |
New_Beijing_3_Degree_Gauss_Kruger_CM_126E |
投影坐标 |
4800 |
New_Beijing_3_Degree_Gauss_Kruger_CM_129E |
投影坐标 |
4822 |
New_Beijing_3_Degree_Gauss_Kruger_CM_135E |
作者:我也是个傻瓜
出处:http://www.cnblogs.com/liweis/
签名:成熟是一种明亮而不刺眼的光辉。
本文转自我也是个傻瓜51CTO博客,原文链接:http://www.cnblogs.com/liweis/p/5951032.html ,如需转载请自行联系原作者