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cocos2d-x中几种存储数据的方式

时间:2014-08-29 17:38:28      阅读:282      评论:0      收藏:0      [点我收藏+]

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说明:本文所论述内容均基于cocos2dx 3.0 版本。

1、UserDefault

它是cocos2d-x用来存取基本数据类型用的。保存为XML文件格式。

查看CCUserDefault文件,可以看出,文件名默认为UserDefault.xml。在win32平台,Debug下,该文件在Debug.win32文件夹内。如果该文件不存在,则会创建新文件。

1 // root name of xml
2 #define USERDEFAULT_ROOT_NAME    "userDefaultRoot"
3 
4 #define XML_FILE_NAME "UserDefault.xml"

用UserDefault

操作方式比较简单:

主要方法:(和java的map很像,键值对,应该很容易懂的)

1 void    setBoolForKey(const char* pKey, bool value);
2 void    setIntegerForKey(const char* pKey, int value);
3 void    setFloatForKey(const char* pKey, float value);
4 void    setDoubleForKey(const char* pKey, double value);
5 void    setStringForKey(const char* pKey, const std::string & value);

通过键读取数据,如果键不存在,可以设置一个defaultValue返回自己想要的值。

1 bool    getBoolForKey(const char* pKey, bool defaultValue = false);
2 int    getIntegerForKey(const char* pKey, int defaultValue = 0);
3 float    getFloatForKey(const char* pKey, float defaultValue=0.0f);
4 double    getDoubleForKey(const char* pKey, double defaultValue=0.0);
5 std::string    getStringForKey(const char* pKey, const std::string & defaultValue = "");

UserDefault封装了对XML文件的处理,提供了简单操作文件的方法,但是不足之处在于固定的文件夹,固定的文件名称。有限的数据类型。

2、FileUtils

 static FileUtils* getInstance();//获取FileUtils类的实例   

在cocos2d-x中,文件读写其实直接使用c/c++中的文件读写操作方法,但是,在实际运用中,由于移动客户端读写文件需要相应的权限,所以读写文件就需要先指定文件的路径,我们不需要获取绝对路径,只需要获取相对路径就行,因为cocos2d-x底层已经做了相应各个平台的处理.

std::string fullPathForFilename(const std::string &filename);//获取文件的完整路径  

std::string getStringFromFile(const std::string& filename);//读取文件中的字符串

Data getDataFromFile(const std::string& filename);//获取文件数据 

可以看下Data类:

 1 class CC_DLL Data
 2 {
 3 public:
 4     static const Data Null;
 5     //构造函数
 6     Data();
 7     Data(const Data& other);
 8     Data(Data&& other);
 9     ~Data();
10     // 重载符号
11     Data& operator= (const Data& other);
12     Data& operator= (Data&& other);
13 
14     unsigned char* getBytes() const;//获取数据
15     ssize_t getSize() const;//尺寸
16     void copy(unsigned char* bytes, const ssize_t size);//从bytes复制
17     void fastSet(unsigned char* bytes, const ssize_t size);//从bytes快速set,使用后bytes将不能在外部使用
18     void clear();//清除
19     bool isNull() const;//判空
20 private:
21     void move(Data& other);
22 private:
23     unsigned char* _bytes;
24     ssize_t _size;
25 };

unsigned char* getFileDataFromZip(const std::string& zipFilePath, const std::string& filename, ssize_t *size);//读取压缩文件数据(zip格式)

如果读取成功size中会返回文件的大小,否则返回0。

如果我们通过setSearchPaths()设置搜索路径("/mnt/sdcard/", "internal_dir/"),然后通过setSearchResolutionsOrder()设置子区分路径("resources-ipadhd/", "resources-ipad/", "resources-iphonehd")。如果搜索文件名为‘sprite.png‘ 那么会先在文件查找字典中查找key: sprite.png -> value: sprite.pvr.gz,然后搜索文件‘sprite.pvr.gz‘如下顺序:

1              /mnt/sdcard/resources-ipadhd/sprite.pvr.gz      (if not found, search next)
2              /mnt/sdcard/resources-ipad/sprite.pvr.gz        (if not found, search next)
3              /mnt/sdcard/resources-iphonehd/sprite.pvr.gz    (if not found, search next)
4              /mnt/sdcard/sprite.pvr.gz                       (if not found, search next)
5              internal_dir/resources-ipadhd/sprite.pvr.gz     (if not found, search next)
6              internal_dir/resources-ipad/sprite.pvr.gz       (if not found, search next)
7              internal_dir/resources-iphonehd/sprite.pvr.gz   (if not found, search next)
8              internal_dir/sprite.pvr.gz                      (if not found, return "sprite.png")

If the filename contains relative path like "gamescene/uilayer/sprite.png",
and the mapping in fileLookup dictionary contains `key: gamescene/uilayer/sprite.png -> value: gamescene/uilayer/sprite.pvr.gz`.
The file search order will be:

/mnt/sdcard/gamescene/uilayer/resources-ipadhd/sprite.pvr.gz (if not found, search next)
/mnt/sdcard/gamescene/uilayer/resources-ipad/sprite.pvr.gz (if not found, search next)
/mnt/sdcard/gamescene/uilayer/resources-iphonehd/sprite.pvr.gz (if not found, search next)
/mnt/sdcard/gamescene/uilayer/sprite.pvr.gz (if not found, search next)
internal_dir/gamescene/uilayer/resources-ipadhd/sprite.pvr.gz (if not found, search next)
internal_dir/gamescene/uilayer/resources-ipad/sprite.pvr.gz (if not found, search next)
internal_dir/gamescene/uilayer/resources-iphonehd/sprite.pvr.gz (if not found, search next)
internal_dir/gamescene/uilayer/sprite.pvr.gz (if not found, return "gamescene/uilayer/sprite.png")

If the new file can‘t be found on the file system, it will return the parameter filename directly.

如果找到返回完整路径,没找到返回‘sprite.png‘。

void loadFilenameLookupDictionaryFromFile(const std::string &filename);//从文件导入文件名查找字典

文件为plist格式如下:

 1    /**
 2      * Loads the filenameLookup dictionary from the contents of a filename.
 3      * 
 4      * @note The plist file name should follow the format below:
 5      * 
 6      * @code
 7      * <?xml version="1.0" encoding="UTF-8"?>
 8      * <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 9      * <plist version="1.0">
10      * <dict>
11      *     <key>filenames</key>
12      *     <dict>
13      *         <key>sounds/click.wav</key>
14      *         <string>sounds/click.caf</string>
15      *         <key>sounds/endgame.wav</key>
16      *         <string>sounds/endgame.caf</string>
17      *         <key>sounds/gem-0.wav</key>
18      *         <string>sounds/gem-0.caf</string>
19      *     </dict>
20      *     <key>metadata</key>
21      *     <dict>
22      *         <key>version</key>
23      *         <integer>1</integer>
24      *     </dict>
25      * </dict>
26      * </plist>
27      * @endcode
28      * @param filename The plist file name.
29      *
30      @since v2.1
31      * @js loadFilenameLookup
32      * @lua loadFilenameLookup
33      */

void setFilenameLookupDictionary(const ValueMap& filenameLookupDict);//从ValueMap中设置文件名查找字典

ValueMap的定义:

 1 typedef std::unordered_map<std::string, Value> ValueMap; 

std::string fullPathFromRelativeFile(const std::string &filename, const std::string &relativeFile);//获取相对应文件的完整路径 

 e.g. filename: hello.png, pszRelativeFile: /User/path1/path2/hello.plist   Return: /User/path1/path2/hello.pvr (If there a a key(hello.png)-value(hello.pvr) in FilenameLookup dictionary. )

 void setSearchResolutionsOrder(const std::vector<std::string>& searchResolutionsOrder);//设置子搜索区分路径

见fullPathForFilename()。

void addSearchResolutionsOrder(const std::string &order);//增加子搜索路径

const std::vector<std::string>& getSearchResolutionsOrder();//获取子搜索区分路径

void setSearchPaths(const std::vector<std::string>& searchPaths);//设置搜索路径

见fullPathForFilename()。

void addSearchPath(const std::string & path);//增加搜索路径

const std::vector<std::string>& getSearchPaths() const;//获取搜索路径

 std::string getWritablePath();//获取一个可写入文件的路径

经过测试在win32平台上,debug版本返回的是程序文件所在的路径,release返回的是“我的文档”路径。

bool isFileExist(const std::string& filePath);//判断文件是否存在

经过测试在win32平台上,如果路径中包含中文字符会找不到文件。所以可以自己写个。

bool isAbsolutePath(const std::string& path);判断是否为绝对路径

 

void setPopupNotify(bool notify);

bool isPopupNotify();

Sets/Gets 当文件加载失败时弹出messagebox.

 

ValueMap getValueMapFromFile(const std::string& filename);//从文件获取ValueMap

bool writeToFile(ValueMap& dict, const std::string& fullPath);//写入一个ValueMap数据到plist格式文件

ValueVector getValueVectorFromFile(const std::string& filename);//从文件获取ValueVector

ValueVector定义:

 1 typedef std::vector<Value> ValueVector; 

函数也就这些了,还没有写demo代码,写好了贴过来。

 

 3.SQLite

4、plist文件读写

在cocos2d-x中,对于plist文件,既可以读取,也可以进行写入的操作;下面先来看一个plist文件:

bubuko.com,布布扣
 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"/>
 3 
 4 <plist version="1.0">
 5     <dict>
 6         <key>string element key</key>
 7         <string>string element value</string>
 8         <key>array</key>
 9         <array>
10             <dict>
11                 <key>string in dictInArray key 0</key>
12                 <string>string in dictInArray value 0</string>
13                 <key>string in dictInArray key 1</key>
14                 <string>string in dictInArray value 1</string>
15             </dict>
16             <string>string in array</string>
17             <array>
18                 <string>string 0 in arrayInArray</string>
19                 <string>string 1 in arrayInArray</string>
20             </array>
21         </array>
22         <key>dictInDict, Hello World</key>
23         <dict>
24             <key>string in dictInDict key</key>
25             <string>string in dictInDict value</string>
26             <key>bool</key>
27             <true/>
28             <key>integer</key>
29             <integer>1024</integer>
30             <key>float</key>
31             <real>1024.1024170</real>
32             <key>double</key>
33             <real>1024.1230000000000000</real>
34         </dict>
35     </dict>
36 </plist>
View Code

先不看上面的plist文件到底有些什么内容;实际上它是由下一段代码生成的。

bubuko.com,布布扣
 1 auto root = Dictionary::create();
 2     auto string = String::create("string element value");
 3     root->setObject(string, "string element key"); // 添加一个键值对
 4     
 5     auto array = Array::create();  // 创建一个array
 6     
 7     auto dictInArray = Dictionary::create();
 8     dictInArray->setObject(String::create("string in dictInArray value 0"), "string in dictInArray key 0");
 9     dictInArray->setObject(String::create("string in dictInArray value 1"), "string in dictInArray key 1");
10     array->addObject(dictInArray); // 往数组中添加一个键值对
11     
12     array->addObject(String::create("string in array")); // 往数组中添加一个字符串
13     
14     auto arrayInArray = Array::create();
15     arrayInArray->addObject(String::create("string 0 in arrayInArray"));
16     arrayInArray->addObject(String::create("string 1 in arrayInArray"));
17     array->addObject(arrayInArray); // 往数组中添加一个数组
18     
19     root->setObject(array, "array");
20     
21     auto dictInDict = Dictionary::create();
22     dictInDict->setObject(String::create("string in dictInDict value"), "string in dictInDict key");
23    
24     //add boolean to the plist
25     auto booleanObject = Bool::create(true);
26     dictInDict->setObject(booleanObject, "bool");
27     
28     //add interger to the plist
29     auto intObject = Integer::create(1024);
30     dictInDict->setObject(intObject, "integer");
31     
32     //add float to the plist
33     auto floatObject = Float::create(1024.1024f);
34     dictInDict->setObject(floatObject, "float");
35     
36     //add double to the plist
37     auto doubleObject = Double::create(1024.123);
38     dictInDict->setObject(doubleObject, "double");
39     
40     root->setObject(dictInDict, "dictInDict, Hello World");
41 // end with /
42     std::string writablePath = FileUtils::getInstance()->getWritablePath();
43     std::string fullPath = writablePath + "text.plist";
44     if(root->writeToFile(fullPath.c_str()))
45         log("see the plist file at %s", fullPath.c_str());
46     else
47         log("write plist file failed");
48     
49     // 读取上面创建的内容
50     auto loadDict = __Dictionary::createWithContentsOfFile(fullPath.c_str());
51     auto loadDictInDict = (__Dictionary*)loadDict->objectForKey("dictInDict, Hello World");
52     auto boolValue = (__String*)loadDictInDict->objectForKey("bool");
53     CCLOG("%s",boolValue->getCString());
54     auto floatValue = (__String*)loadDictInDict->objectForKey("float");
55     CCLOG("%s",floatValue->getCString());
56     auto intValue = (__String*)loadDictInDict->objectForKey("integer");
57     CCLOG("%s",intValue->getCString());
58     auto doubleValue = (__String*)loadDictInDict->objectForKey("double");
59     CCLOG("%s",doubleValue->getCString());
View Code

因此可以看出,对符合一定格式的plist文件,可以通过Dictionary进行操作。cocos2dx 3.0 的Dictionary,可以实现对Array,Dictionary,Integer,String,Bool等基础数据类型进行读写。

下面再来看另一种读取方式: 假定plist文件如下;

bubuko.com,布布扣
1 <plist version="1.0">
2 <dict>
3     <key>name</key>
4     <string>Ls</string>
5     <key>isgirl</key>
6     <false/>
7 </dict>
8 </plist>
View Code

读取方式二,这种方法是借助VectorMap来进行读的:

bubuko.com,布布扣
1  FileUtils * fu = FileUtils::getInstance();
2     ValueMap vm = fu->getValueMapFromFile("Info.plist");
3     log("%s", vm["name"].asString().c_str()); // 读取string -->Ls
4     bool bl = vm["isgirl"].asBool(); // 读取bool -->0
5     log("%d", bl);
View Code

如果文件节点也是一个ValueMap,则可以通过xm["xx"].asValueMap()将节点转换为ValueMap;如果根节点为数组也可能直接通过ValueVector.getValueVectorFromFile("xx")读取数据;

5、xml文件读取

bubuko.com,布布扣
 1 FileUtils * fu = FileUtils::getInstance();
 2     auto doc = new tinyxml2::XMLDocument();
 3     doc->Parse(fu->getStringFromFile("data.xml").c_str());
 4     auto root = doc->RootElement();
 5     for (auto e = root->FirstChildElement(); e; e = e->NextSiblingElement()) {
 6         std::string str;
 7         for (auto attr = e->FirstAttribute(); attr; attr = attr->Next()) {
 8             str += attr->Name();
 9             str += ":";
10             str += attr->Value();
11             str += ",";
12         }
13         log("%s", str.c_str());
14     }
View Code

data.xml

1 <data>
2     <p name="zs" age="23"/>
3     <p name="ls" age="25"/>
4 </data>

上面的代码输出内容为:

cocos2d: name:zs,age:23,
cocos2d: name:ls,age:25,

注:需要导入cosos2d-x库 <tinyxml2/tinyxml2.h>

6、JSON文件读取

先来看一个json  :  [{"name": "zs","age": 23}, {"name": "ls","age": 25}]

1  rapidjson::Document d;
2     d.Parse<0>(fu->getStringFromFile("dj.json").c_str()); // 0表示默认的解析方式;
3     log("%s", d[rapidjson::SizeType(0)]["name"].GetString());

注:需要导入cocos2d-x库  <json/document.h>

cocos2d-x中几种存储数据的方式

标签:style   blog   http   color   os   使用   java   io   strong   

原文地址:http://www.cnblogs.com/slysky/p/3945331.html

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