title: Invoke block iOS
body: <p>I try to invoke some block, but I run into a EXC_BAD_ACCESS.</p>
  
  <pre><code>-(void) methodA {
     self.block = ^ {
         [self methodB];
     };
  }
  
  -(void) webViewDidFinishLoad:(UIWebView *)webView {
         [block invoke]; // error here (block is not valid id type).
  }
  
  -(void)methodB {
      //do something
  }
  </code></pre>
  
  <p>Any thoughts on why this is happening?</p>