怎样把一个自定义的类绑定到JS RUNTIME

说是原创，其实还是看了网上各种教程。主要看的是这篇：http://www.cocos2d-x.org/docs/manual/code-ide/function-guides/add-3rd-party-lib/binding-custom-class-to-js/zh

但也整了好几天，有的是因为自己没有看清楚，有的是环境出了问题或者版本可能不一致吧。我用的cocos2dx-js 3.3版本。在此记录一下，希望能给需要的人一些帮助。因为刚开始，自己好多概念性的东西也没有搞明白，只是在js能调到c++代码了。

这个文档的目的是展示一下怎样把一个自定义的cpp类绑定到js runtime。**不涉及jsbinding的细节**。

首先写一个C++类

Utils.h

#include "cocos2d.h"

namespace cocos2d {

class Utils: public cocos2d::Ref{

public:

Utils();

~Utils();

bool init();

std::string helloMsg();

CREATE_FUNC(Utils);

};

} //namespace cocos2d

Utils.cpp

#include "Utils.h"

USING_NS_CC;

Utils::Utils(){

}

Utils::~Utils(){

}

bool Utils::init(){

return true;

}

std::string Utils::helloMsg(){

return "hello from Utils:sayHello";

}

这两个C++文件，放在 /frameworks/js-bindings/cocos2d-x/cocos/my目录下，（这里是在cocos目录下创建了my目录的）

然后把这个my连同Utils.h Utils.cpp文件加到cocos2d_libs.xcodeproj项目里，如下图所示：



一定要注意别加错工程了。

然后在cocos2d_js_bindings.xcodeproj工程里添加源文件路径，如下图所示：



重要的事情在强调一遍，一定要看清楚是在哪个工程下边加的。当初吃了亏啊。

然后这里提前在项目工程的搜索路径中添加绑定文件的路径，如下图所示：



其实我们这里生成的绑定文件就是在auto里。

那么我们现在来生成绑定文件：

在项目下的 /tools/tojs路径下添加cocos2dx_utils.ini文件

[cocos2dx_utils]

# the prefix to be added to the generated functions. You might or might not use this in your own

# templates

prefix = cocos2dx_utils

# create a target namespace (in javascript, this would create some code like the equiv. to `ns = ns || {}`)

# all classes will be embedded in that namespace

target_namespace = cc

android_headers = -I%(androidndkdir)s/platforms/android-14/arch-arm/usr/include -I%(androidndkdir)s/sources/cxx-stl/gnu-libstdc++/4.7/libs/armeabi-v7a/include -I%(androidndkdir)s/sources/cxx-stl/gnu-libstdc++/4.7/include -I%(androidndkdir)s/sources/cxx-stl/gnu-libstdc++/4.8/libs/armeabi-v7a/include
-I%(androidndkdir)s/sources/cxx-stl/gnu-libstdc++/4.8/include

android_flags = -D_SIZE_T_DEFINED_

clang_headers = -I%(clangllvmdir)s/lib/clang/3.3/include

clang_flags = -nostdinc -x c++ -std=c++11

cocos_headers = -I%(cocosdir)s/cocos -I%(cocosdir)s/my -I%(cocosdir)s/cocos/base -I%(cocosdir)s/cocos/platform/android

cocos_flags = -DANDROID -DCOCOS2D_JAVASCRIPT

cxxgenerator_headers =

# extra arguments for clang

extra_arguments = %(android_headers)s %(clang_headers)s %(cxxgenerator_headers)s %(cocos_headers)s %(android_flags)s %(clang_flags)s %(cocos_flags)s %(extra_flags)s

# what headers to parse

headers = %(cocosdir)s/cocos/my/Utils.h

# what classes to produce code for. You can use regular expressions here. When testing the regular

# expression, it will be enclosed in "^$", like this: "^Menu*$".

classes = Utils.*

# what should we skip? in the format ClassName::[function function]

# ClassName is a regular expression, but will be used like this: "^ClassName$" functions are also

# regular expressions, they will not be surrounded by "^$". If you want to skip a whole class, just

# add a single "*" as functions. See bellow for several examples. A special class name is "*", which

# will apply to all class names. This is a convenience wildcard to be able to skip similar named

# functions from all classes.

skip =

rename_functions =

rename_classes =

# for all class names, should we remove something when registering in the target VM?

remove_prefix =

# classes for which there will be no "parent" lookup

classes_have_no_parents =

# base classes which will be skipped when their sub-classes found them.

base_classes_to_skip = Ref Clonable

# classes that create no constructor

# Set is special and we will use a hand-written constructor

abstract_classes =

# Determining whether to use script object(js object) to control the lifecycle of native(cpp) object or the other way around. Supported values are 'yes' or 'no'.

script_control_cpp = no

然后修改tools/tojs/genbindings.py文件，添加最后一行。

cmd_args = {'cocos2dx.ini' : ('cocos2d-x', 'jsb_cocos2dx_auto'), \

'cocos2dx_extension.ini' : ('cocos2dx_extension', 'jsb_cocos2dx_extension_auto'), \

'cocos2dx_builder.ini' : ('cocos2dx_builder', 'jsb_cocos2dx_builder_auto'), \

'cocos2dx_ui.ini' : ('cocos2dx_ui', 'jsb_cocos2dx_ui_auto'), \

'cocos2dx_studio.ini' : ('cocos2dx_studio', 'jsb_cocos2dx_studio_auto'), \

'cocos2dx_spine.ini' : ('cocos2dx_spine', 'jsb_cocos2dx_spine_auto'), \

'cocos2dx_utils.ini' : ('cocos2dx_utils', 'jsb_cocos2dx_utils_auto'), \

}

然后运行 tools/tojs/genbindings.py， python genbindings.py命令。之前命令用错了还是少环境的，一顿折腾。

运行完命令之后，就会在/js-bindings/cocos2d-x/plugin/jsbindings/auto目录下生成jsb_cocos2dx_utils_auto.hpp jsb_cocos2dx_utils_auto.cpp文件。

然后把这俩文件添加到cocos2d_js_bindings.xcodeproj工程下边。

添加到工程下边，是指的，在工程target下对应的Build Phases下边能看到



看清是加到哪个工程下边了。

然后就是注册到js

可以看到jsb_cocos2dx_utils_auto.hpp下有方法register_all_cocos2dx_utils，

我们在AppDelegate.cpp里，添加

#include "jsb_cocos2dx_utils_auto.hpp"

sc->addRegisterCallback(register_all_cocos2dx_utils);

就齐活了。
编译之后，接下来就是在js里调用了：
var utilsClass = cc.Utils.create();

var msg = utilsClass.helloMsg();

cc.log("utilsClass's msg is : "+msg);

可以看到输出：

JS: utilsClass's msg is : hello from Utils:sayHello

此时，完工！
自己亲测成功的。虽然好多不明白，但会继续看手动绑定，多了就明白了，至少能调到了。网上教程好多，千万不要总是试，总是半途而废，遇到问题要多想想解决办法，要不然到头来会浪费很多时间。