问题是当我将xml转换为json时，除了一个外，它不显示属性。这是我的代码：
<?php
$url="write.xml";
$fileContents= file_get_contents($url);
$fileContents = str_replace(array("\n", "\r", "\t"), '', $fileContents);
$fileContents = trim(str_replace('"', "'", $fileContents));
$simpleXml = simplexml_load_string($fileContents);
$json = json_encode($simpleXml);
print $json;
?>
这里是write.xml文件：
<?xml version="1.0"?>
<information>
<history Placename="Rohtas_Fort">
<wiki>Rohtas Fort is a historical garrison fort located near the city of Jhelum in Punjab, Pakistan. It was built by Raja Todar Mal, under the orders of the Afghan king Sher Shah Suri, to subdue the rebellious tribes of the northern Punjab region, in the 16th century. This fort is about 4 km in circumference</wiki>
<year y="1555">The Rohtas fort was built to crush the local tribes of Potohar, who rebelled against the Sur dynasty after the Mughal emperor Humayun was ousted by the former.
It took eight years to built the fort, it was captured by Mughal emperor Humayun in 1555.The Rohtas fort was built to crush the local tribes of Potohar, who rebelled against the Sur dynasty after the Mughal emperor Humayun was ousted by the former.
It took eight years to built the fort, it was captured by Mughal emperor Humayun in 1555.</year>
<year y="2005">In the portions that have fallen away one can still see some part of the original construction.
The central archway of the Chandwali Gate has been rebuilt recently so that is the only “fake” part of the fort.
In early 2005, seepage, heavy rains, and general neglect caused the left inner face of the Talaqi Gate to collapse, and the right flank and foundation to become detached from the original structure.
The Gatali Gate forms one of the original entrances to Rohtas</year>
<year y="1997">Over time, its right bastion and supporting wall have collapsed as a result of permeated rainwater and the erosion of its foundations.
=== World Heritage Site ===
Qila Rohtas was designated a World Heritage Site in 1997...It is undertaking the following projects in conjunction with the Royal Norwegian Embassy.
Complete restoration of Shah Chandwali Gate
Conservation of Haveli Man Singh
Conservation of Talaqi Gate and Gatali Gate
Establishment of Sher Shah Suri Museum in upper storey of Sohail Gate
Improvement of quality of life in Rohtas Fort village
== Nearby places of historical significance ==
Outside the Langar Khani Gate is the tomb of a lady called Khair Un Nisa.She was the daughter of the food minister named Qadir Bukhsh.She died here and was buried in this tomb but she was later moved to Sasaram.
Until the construction of the new Grand Trunk Road, Rohtas was a halting place on the main Peshawar-Lahore road.This road had serais about a mile apart.One of these is about one mile north of the Rohtas Fort.It is in a fair state of preservation.
== How to visit ==
=== From Islamabad ===
The dual-carriage Grand Trunk Road takes you past Gujar Khan and Sohawa, to the small town of Dina 130 km away.Just past Dina you will drive over a railway overpass, stay to the right of the road and take the first U-turn to drive back towards Dina.After about 100 meters to your left you will find a signpost, which indicates the way towards the road leading to Rohtas Fort which is 8 km away, past the small holy village of Muftian home to the Mufti Tribe.Drive on the road to enter into the fort and keep driving till you reach the parking area.
=== From Lahore ===
Drive on G.T road past Gujranwala, Wazirabad and the city of Jhelum.About 10 minutes drive beyond the Jhelum bridge just short of the city of Dina, you will find a signpost to the left directing you to Rohtas Fort.
== Gallery ==</year>
<image>http://cdn.shopify.com/s/files/1/0015/2602/products/Reggie-and-the-Full-Effect-No-Country-for-Old-Musicians-560x560_1024x1024.jpg?v=1385489227</image>
<image>http://i.telegraph.co.uk/multimedia/archive/02537/elderly_2537613b.jpg</image>
<image>http://thumb101.shutterstock.com/display_pic_with_logo/3391/176510147/stock-photo-full-length-portrait-of-an-old-man-with-cane-gesturing-with-hand-isolated-on-white-background-176510147.jpg</image>
<image>https://s3.amazonaws.com/media.wbur.org/wordpress/11/files/2015/04/0423_full-house.jpg</image>
<image y="1888">http://upload.wikimedia.org/wikipedia/commons/3/39/Poison,_a_Cheyenne_woman_almost_100_years_old,_full-length,_seated,_1888_-_NARA_-_530905.jpg</image>
<image y="2008">http://i.dailymail.co.uk/i/pix/2008/12/27/article-1102017-02E58EE0000005DC-791_233x405.jpg</image>
<image y="2011">http://news.fulltiltboots.com/wp-content/uploads/2011/12/november-winner2.jpg</image>
<image y="2013">http://cdn.inquisitr.com/wp-content/uploads/2013/11/Full-House-Spinoff-Show-Coming-To-Television-665x385.jpg</image>
</history>
</information>
和输出：
{"history":{"@attributes":{"Placename":"Rohtas_Fort"},"wiki":"Rohtas Fort is a historical garrison fort located near the city of Jhelum in Punjab, Pakistan. It was built by Raja Todar Mal, under the orders of the Afghan king Sher Shah Suri, to subdue the rebellious tribes of the northern Punjab region, in the 16th century. This fort is about 4 km in circumference","year":["The Rohtas fort was built to crush the local tribes of Potohar, who rebelled against the Sur dynasty after the Mughal emperor Humayun was ousted by the former.It took eight years to built the fort, it was captured by Mughal emperor Humayun in 1555.The Rohtas fort was built to crush the local tribes of Potohar, who rebelled against the Sur dynasty after the Mughal emperor Humayun was ousted by the former.It took eight years to built the fort, it was captured by Mughal emperor Humayun in 1555.","In the portions that have fallen away one can still see some part of the original construction.The central archway of the Chandwali Gate has been rebuilt recently so that is the only \u201cfake\u201d part of the fort.In early 2005, seepage, heavy rains, and general neglect caused the left inner face of the Talaqi Gate to collapse, and the right flank and foundation to become detached from the original structure.The Gatali Gate forms one of the original entrances to Rohtas","Over time, its right bastion and supporting wall have collapsed as a result of permeated rainwater and the erosion of its foundations.=== World Heritage Site ===Qila Rohtas was designated a World Heritage Site in 1997...It is undertaking the following projects in conjunction with the Royal Norwegian Embassy.Complete restoration of Shah Chandwali GateConservation of Haveli Man SinghConservation of Talaqi Gate and Gatali GateEstablishment of Sher Shah Suri Museum in upper storey of Sohail GateImprovement of quality of life in Rohtas Fort village== Nearby places of historical significance ==Outside the Langar Khani Gate is the tomb of a lady called Khair Un Nisa.She was the daughter of the food minister named Qadir Bukhsh.She died here and was buried in this tomb but she was later moved to Sasaram.Until the construction of the new Grand Trunk Road, Rohtas was a halting place on the main Peshawar-Lahore road.This road had serais about a mile apart.One of these is about one mile north of the Rohtas Fort.It is in a fair state of preservation.== How to visit ===== From Islamabad ===The dual-carriage Grand Trunk Road takes you past Gujar Khan and Sohawa, to the small town of Dina 130 km away.Just past Dina you will drive over a railway overpass, stay to the right of the road and take the first U-turn to drive back towards Dina.After about 100 meters to your left you will find a signpost, which indicates the way towards the road leading to Rohtas Fort which is 8 km away, past the small holy village of Muftian home to the Mufti Tribe.Drive on the road to enter into the fort and keep driving till you reach the parking area.=== From Lahore ===Drive on G.T road past Gujranwala, Wazirabad and the city of Jhelum.About 10 minutes drive beyond the Jhelum bridge just short of the city of Dina, you will find a signpost to the left directing you to Rohtas Fort.== Gallery =="],"image":["http:\/\/cdn.shopify.com\/s\/files\/1\/0015\/2602\/products\/Reggie-and-the-Full-Effect-No-Country-for-Old-Musicians-560x560_1024x1024.jpg?v=1385489227","http:\/\/i.telegraph.co.uk\/multimedia\/archive\/02537\/elderly_2537613b.jpg","http:\/\/thumb101.shutterstock.com\/display_pic_with_logo\/3391\/176510147\/stock-photo-full-length-portrait-of-an-old-man-with-cane-gesturing-with-hand-isolated-on-white-background-176510147.jpg","https:\/\/s3.amazonaws.com\/media.wbur.org\/wordpress\/11\/files\/2015\/04\/0423_full-house.jpg","http:\/\/upload.wikimedia.org\/wikipedia\/commons\/3\/39\/Poison,_a_Cheyenne_woman_almost_100_years_old,_full-length,_seated,_1888_-_NARA_-_530905.jpg","http:\/\/i.dailymail.co.uk\/i\/pix\/2008\/12\/27\/article-1102017-02E58EE0000005DC-791_233x405.jpg","http:\/\/news.fulltiltboots.com\/wp-content\/uploads\/2011\/12\/november-winner2.jpg","http:\/\/cdn.inquisitr.com\/wp-content\/uploads\/2013\/11\/Full-House-Spinoff-Show-Coming-To-Television-665x385.jpg"]}}
您可以看到输出中没有“Y”属性。
答案 0 :(得分：0)
在SimpleXML对象上调用的json_encode（）生成的JSON字符串将不具有属性，json不支持属性。将您从Simplexml_load_string获得的SimpleXML对象转换为数组并将属性添加到该数组，然后在该数组上使用json_encode。
可以找到创建数组的强大功能here。
以下是xml的编码示例。