RN中JavaScriptCore的介绍

其实都是从袁峥Seemygo 这里学来的。

1、OC获取定义在JS中的变量，并通过OC直接修改JS中变量的值

-(void)getJSVar{
    //创建JS代码
    NSString *jsCode = @"var arr = [1,2,3]";
    //创建js运行环境
    JSContext *ctx = [[JSContext alloc]init];
    //执行JS代码
    [ctx evaluateScript:jsCode];
    //执行完JS代码之后，获取JS变量,可以使用JSContext通过变量名称获取
    JSValue *jsArr = ctx[@"arr"];
    
    jsArr[0] = @5;
    
    NSLog(@"%@",jsArr);
    
}

2017-04-01 09:49:44.809 React Native[12515:2883299] 5,2,3

2、OC调用JS方法，并获取返回结果

-(void)ocCallJSFunc{
    NSString *jsCode = @"function hello(say){"
    "return say;"
    "}";
    
    JSContext *ctx = [[JSContext alloc]init];
    
    [ctx evaluateScript:jsCode];
    
    JSValue *hello = ctx[@"hello"];//使用JSContext通过函数名称获取
    
    JSValue *res = [hello callWithArguments:@[@"hello"]];//这里的参数需要一个数组
    
    NSLog(@"%@",res);
    
}

2017-04-01 10:08:56.561 React Native[12553:2898397] hello

3、JS调用OC中不带参数的block

-(void)jsCallOCBlockWithoutArguments{
    JSContext *ctx = [[JSContext alloc]init];
    
    NSString *jsCode = @"eat()";
    
    ctx[@"eat"] = ^(){
        NSLog(@"吃");
    };
    
    [ctx evaluateScript:jsCode];
}

2017-04-01 10:24:14.918 React Native[12596:2906751] 吃

4、JS调用OC中带参数的block

-(void)jsCallBlockWithArguments{
    JSContext *ctx = [[JSContext alloc]init];
    
    ctx[@"eat"] = ^(){
        NSArray *arguments = [JSContext currentArguments];
        NSLog(@"吃%@",arguments[0]);
    };
    
    NSString *jsCode = @"eat('面包')";//注意'面包'
    
    [ctx evaluateScript:jsCode];
    
}

2017-04-01 10:31:18.915 React Native[12625:2912073] 吃面包

5、JS调用OC 自定义类
 在JS中并没有OC的类，需要在JS中生成OC的类，以及JS中的属性和方法也要在JS中生成

• 步骤：
• 自定义协议:

#import <Foundation/Foundation.h>
#import <JavaScriptCore/JavaScriptCore.h>

@protocol PersonJSExport <JSExport>
@property (nonatomic,strong)NSString *name;

-(void)play;

JSExportAs(playGame,-(void)playWithGame:(NSString *)game time:(NSString *)time);
@end

• 自定义类

#import "PersonJSExport.h"

@interface Person : NSObject<PersonJSExport>
@property (nonatomic,strong)NSString *name;
-(void)playWithGame:(NSString *)game time:(NSString *)time;

@end

#import "Person.h"

@implementation Person
-(void)play{
    NSLog(@"%@玩",_name);
}

-(void)playWithGame:(NSString *)game time:(NSString *)time{
    NSLog(@"%@在%@玩%@",_name,time,game);
}
@end

• JS调用自定义的类

-(void)jsCallCustonClass{
    Person *p = [[Person alloc]init];
    p.name =@"mudy";
    
    JSContext *ctx = [[JSContext alloc]init];
    ctx[@"onePerson"] = p;
    
    NSString *jsCode = @"onePerson.playGame('王者荣耀','凌晨')";
//    NSString *jsCode = @"onePerson.play()";
    [ctx evaluateScript:jsCode];
}

2017-04-01 13:07:22.802 React Native[12952:2993038] mudy在凌晨玩王者荣耀