iOS开发在js中调用oc可以实现在HTML5中调用手机系统的相册，拍照等。

控制器.m的实现如下

#import "ViewController.h"

@interface ViewController () <UIWebViewDelegate>
@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // 1.webView
    UIWebView *webView = [[UIWebView alloc] init];
    webView.frame = self.view.bounds;
    webView.delegate = self;
    [self.view addSubview:webView];
    
    // 2.加载网页
    NSURL *url = [[NSBundle mainBundle] URLForResource:@"test" withExtension:@"html"];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    [webView loadRequest:request];
}

#pragma mark - UIWebViewDelegate

/**
 *  webView每当发送一个请求之前，都会先调用这个方法（能拦截所有请求）,利用这个特性，和服务器协商一个自定义的协议头，如“test://”
    
    js中的响应的方法代码如下
    function fn_call() {
    window.location.href = 'test://call';
 }

 */
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    NSString *url = request.URL.absoluteString;
    NSRange range = [url rangeOfString:@"test://"];
    NSUInteger loc = range.location;
    if (loc != NSNotFound) { // url的协议头是test
        // 方法名
        NSString *method = [url substringFromIndex:loc + range.length];
        
        // 转成SEL
        SEL sel = NSSelectorFromString(method);
        [self performSelector:sel withObject:nil];
    }
    return YES;
}

/**
 *  打电话
 */
- (void)call
{
    NSLog(@"call----");
}

/**
 *  打开照相机
 */
- (void)openCamera
{
    NSLog(@"openCamera----");
}

@end
#import "ViewController.h"

@in