JavaScript与OC交互

2016-03-27 本文已影响23人选一个昵称呗

[[[UIWebView alloc] init] stringByEvaluatingJavaScriptFromString:@"alert(100);"];//oc直接运行js代码

html代码

<html>
<!-- 网页的描述信息 -->
<head>
<meta charset="UTF-8">
<title>第一个网页</title>

<script>
function login()
{
    // 让webView跳转到百度页面（加载百度页面）
    location.href = 'JavaScript://sendMessage_number2_number3_?100&100&99';
}
</script>
</head>

<!-- 网页的具体内容 -->
<body>

<button style="background: red; width:100px; height:30px;" onclick="login();">Call</button>

</body>
</html>

OC代码

-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
  // url == JavaScript://sendMessage_?200
  NSString *url = request.URL.absoluteString;
  NSString *scheme = @"JavaScript://";
  if ([url hasPrefix:scheme]) {
      // 获得协议后面的路径  path == sendMessage_number2_?200&300
      NSString *path = [url substringFromIndex:scheme.length];
      // 利用?切割路径
      NSArray *subpaths = [path componentsSeparatedByString:@"?"];
      // 方法名 methodName == sendMessage:number2:
      NSString *methodName = [[subpaths firstObject] stringByReplacingOccurrencesOfString:@"_" withString:@":"];
      // 参数  200&300
      NSArray *params = nil;
      if (subpaths.count == 2) {
          params = [[subpaths lastObject] componentsSeparatedByString:@"&"];
      }
      // 调用
      [self performSelector:NSSelectorFromString(methodName) withObjects:params];
      
      return NO;
  }
  
  NSLog(@"想加载其他请求，不是想调用OC的方法");
  
  return YES;
}

- (id)performSelector:(SEL)selector withObjects:(NSArray *)objects
{
  // 方法签名(方法的描述)
  NSMethodSignature *signature = [[self class] instanceMethodSignatureForSelector:selector];
  if (signature == nil) {
      [NSException raise:@"错误" format:@"%@方法找不到", NSStringFromSelector(selector)];
  }
  
  // NSInvocation : 利用一个NSInvocation对象包装一次方法调用（方法调用者、方法名、方法参数、方法返回值）
  NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
  invocation.target = self;
  invocation.selector = selector;
  
  // 设置参数
  NSInteger paramsCount = signature.numberOfArguments - 2; // 除self、_cmd以外的参数个数
  paramsCount = MIN(paramsCount, objects.count);
  for (NSInteger i = 0; i < paramsCount; i++) {
      id object = objects[i];
      if ([object isKindOfClass:[NSNull class]]) continue;
      [invocation setArgument:&object atIndex:i + 2];
  }
  
  // 调用方法
  [invocation invoke];
  
  // 获取返回值
  id returnValue = nil;
  if (signature.methodReturnLength) { // 有返回值类型，才去获得返回值
      [invocation getReturnValue:&returnValue];
  }
  
  return returnValue;
}
- (void)sendMessage:(NSString *)number number2:(NSString *)number2 number3:(NSString *)number3
 {
 NSLog(@"%s %@ %@ %@", __func__, number, number2, number3);
 }

JavaScript与OC交互

猜你喜欢

热点阅读