cocos2d-js 3.0 jsb环境调用底层Objective-C代码

Author: faint2death

ios-jsb.md

@@ -0,0 +1,133 @@
+# cocos2d-js 3.0 jsb环境调用底层Objective-C代码
+
+------
+
+## 1. 注册jsb函数
+
+------
+
+比android要简单，因为Xcode可以C++和Objective-C混编的。环境升级到cocos2d-js 3.0 rc0，准备给javascript加一个osInfo的函数，来判断用户的系统信息以及网络信息。
+
+首先在项目目录下的frameworks/runtime-src/Classes/目录添加jsb_ios_info.h的头文件，内容如下：
+
+```c
+#include "cocos2d_specifics.hpp"
+#include "cocos2d.h"
+
+#import "sys/sysctl.h"
+
+std::string os_info();
+bool jsb_os_info(JSContext *cx, uint32_t argc, JS::Value *vp);
+void register_jsb_os_info(JSContext* cx, JSObject* obj);
+```
+
+增加jsb_ios_info.mm文件，内容如下：
+
+```c
+#include "jsb_ios_info.h"
+
+std::string os_info() {
+    size_t size;
+    int nR = sysctlbyname("hw.machine", NULL, &size, NULL, 0);
+    char *machine = (char *)malloc(size);
+    nR = sysctlbyname("hw.machine", machine, &size, NULL, 0);
+    NSString *platform = [NSString stringWithCString:machine encoding:NSUTF8StringEncoding];
+    free(machine);
+     
+    if ([platform isEqualToString:@"iPhone1,1"]) {
+        platform = @"iPhone";
+    } else if ([platform isEqualToString:@"iPhone1,2"]) {
+        platform = @"iPhone 3G";
+    } else if ([platform isEqualToString:@"iPhone2,1"]) {
+        platform = @"iPhone 3GS";
+    } else if ([platform isEqualToString:@"iPhone3,1"]||[platform isEqualToString:@"iPhone3,2"]||[platform isEqualToString:@"iPhone3,3"]) {
+        platform = @"iPhone 4";
+    } else if ([platform isEqualToString:@"iPhone4,1"]) {
+        platform = @"iPhone 4S";
+    } else if ([platform isEqualToString:@"iPhone5,1"]||[platform isEqualToString:@"iPhone5,2"]) {
+        platform = @"iPhone 5";
+    }else if ([platform isEqualToString:@"iPhone5,3"]||[platform isEqualToString:@"iPhone5,4"]) {
+        platform = @"iPhone 5C";
+    }else if ([platform isEqualToString:@"iPhone6,2"]||[platform isEqualToString:@"iPhone6,1"]) {
+        platform = @"iPhone 5S";
+    }else if ([platform isEqualToString:@"iPod4,1"]) {
+        platform = @"iPod touch 4";
+    }else if ([platform isEqualToString:@"iPod5,1"]) {
+        platform = @"iPod touch 5";
+    }else if ([platform isEqualToString:@"iPod3,1"]) {
+        platform = @"iPod touch 3";
+    }else if ([platform isEqualToString:@"iPod2,1"]) {
+        platform = @"iPod touch 2";
+    }else if ([platform isEqualToString:@"iPod1,1"]) {
+        platform = @"iPod touch";
+    } else if ([platform isEqualToString:@"iPad3,2"]||[platform isEqualToString:@"iPad3,1"]) {
+        platform = @"iPad 3";
+    } else if ([platform isEqualToString:@"iPad2,2"]||[platform isEqualToString:@"iPad2,1"]||[platform isEqualToString:@"iPad2,3"]||[platform isEqualToString:@"iPad2,4"]) {
+        platform = @"iPad 2";
+    }else if ([platform isEqualToString:@"iPad1,1"]) {
+        platform = @"iPad 1";
+    }else if ([platform isEqualToString:@"iPad2,5"]||[platform isEqualToString:@"iPad2,6"]||[platform isEqualToString:@"iPad2,7"]) {
+        platform = @"ipad mini";
+    } else if ([platform isEqualToString:@"iPad3,3"]||[platform isEqualToString:@"iPad3,4"]||[platform isEqualToString:@"iPad3,5"]||[platform isEqualToString:@"iPad3,6"]) {
+        platform = @"ipad 3";
+    }
+
+    NSString *info = [NSString stringWithFormat:@"%@|%@", platform, [UIDevice currentDevice].systemVersion];
+
+    std::string *str = new std::string([info UTF8String]);
+
+    return *str;
+}
+
+bool jsb_os_info(JSContext *cx, uint32_t argc, JS::Value *vp) {
+    jsval ret = std_string_to_jsval(cx, os_info());
+    JS_SET_RVAL(cx, vp, ret);
+
+    return true;
+}
+
+void register_jsb_os_info(JSContext *cx, JSObject *obj) {
+    JS_DefineFunction(cx, obj, "osInfo", jsb_os_info, 0, 0);  
+}
+```
+
+然后修改同目录下AppDelegate.cpp文件，添加相应的引用和注册javascript函数：
+
+```c
+...
+#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
+#include "jsb_ios_info.h"
+#endif
+...
+    sc->addRegisterCallback(register_jsb_os_info);
+    
+#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID)
+    sc->addRegisterCallback(JavascriptJavaBridge::_js_register);
+#endif
+    sc->start();
+...
+```
+
+最后在Xcode的Classes目录添加jsb_ios_info.h和jsb_ios_info.mm这两个文件，编译后就可以在js端调用osInfo这个函数了。
+
+## 2. javascript端执行效果
+
+------
+
+用javascript的osInfo函数返回大概是这样的：
+
+```
+iPhone 4S|7.1.2
+```
+
+整个过程比android简单的多。
+
+## 3. 反射机制调用
+
+------
+
+在写android jsb文档的时候，提到ios有没有像android那样的反射机制调用，结果昨天看到cocos2d-js的github合并了一个新功能，就是反射机制调用Objective-C：
+
+https://github.com/cocos2d/cocos2d-js/pull/574
+
+有兴趣的童鞋可以试一下，但个人觉得意义不是很大，因为Xcode支持C++和Objective-C混编，反射机制在ios jsb情况下省不了什么的工作量。