ios - 程序中出现意外的 '@'

Question

我是iOS开发的新手，所以遇到这样的错误时我找不到任何线索，代码如下:

- (void)postToWall {

    FBStreamDialog *dialog = [[[FBStreamDialog alloc] init]
                              autorelease];
    dialog.userMessagePrompt = @"Enter your message:";
     dialog.attachment = [NSString
                         stringWithFormat:@"{\"name\":\"Facebook Connect for
                         iPhone\",\"href\":\"http://developers.facebook.com/
                         connect.phptab=iphone\",\"caption\":\"Caption\",
                         \"description\":\"Description\",\"media\":[{\"type\":
                         \"image\",\"src\":\"http://img40.yfrog.com/img40/
                      5914/iphoneconnectbtn.jpg\",\"href\":
                         \"http://developers.facebook.com/connect.php?
                         tab=iphone/\"}],\"properties\":{\"another link\":
                         {\"text\":\"Facebook home page\",\"href\":
                             \"http://www.facebook.com\"}}}"];
                         [dialog show];

   }

我正在尝试从有关 facebook connect 的在线教程中学习，所以我在代码中遇到了这个错误，文件包括:

导入“FBSession.h”导入“FBLoginButton.h”

您认为这可能是导致问题的原因吗？

Answer 1

要么将字符串写在一行中，要么在每行的结尾和开头添加":

dialog.attachment = [NSString
               stringWithFormat:@"{\"name\":\"Facebook Connect for"
               "iPhone\",\"href\":\"http://developers.facebook.com/"
               "connect.phptab=iphone\",\"caption\":\"Caption\","
               "\"description\":\"Description\",\"media\":[{\"type\":"
               "\"image\",\"src\":\"http://img40.yfrog.com/img40/"
               "5914/iphoneconnectbtn.jpg\",\"href\":"
               "\"http://developers.facebook.com/connect.php?"
               "tab=iphone/\"}],\"properties\":{\"another link\":"
               "{\"text\":\"Facebook home page\",\"href\":"
                   "\"http://www.facebook.com\"}}}"];

另外，请注意，在这种情况下您不需要使用 stringWithFormat，您可以像这样创建字符串:

dialog.attachment = @"{\"name\":\"Facebook Connect for"
           "iPhone\",\"href\":\"http://developers.facebook.com/"
           "connect.phptab=iphone\",\"caption\":\"Caption\","
           "\"description\":\"Description\",\"media\":[{\"type\":"
           "\"image\",\"src\":\"http://img40.yfrog.com/img40/"
           "5914/iphoneconnectbtn.jpg\",\"href\":"
           "\"http://developers.facebook.com/connect.php?"
           "tab=iphone/\"}],\"properties\":{\"another link\":"
           "{\"text\":\"Facebook home page\",\"href\":"
           "\"http://www.facebook.com\"}}}";