无法初始化与一个NSData的NSMutableData（其中包含一个PNG）

Question

有在我iPhone应用程序一个错误。我用的是CameraPicker做出，并得到一张照片，然后我把它送给我的梅索德sendPhoto，这将照片发送到TweetPhoto。直到我初始化的NSData的NSMutableDate一切都很正常。下面是代码：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    [picker dismissModalViewControllerAnimated:YES];
    NSData *imageData = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
    [self sendPhoto:(NSString*)@"lola" tweet:(BOOL)TRUE photo:(NSData*)imageData tags:(NSString*)@"" longitude:(float)1024 latitude:(float)512];
}

下面是sendPhoto-梅索德：

- (void)sendPhoto:(NSString*)message tweet:(BOOL)tweet photo:(NSData*)photo tags:(NSString*)tags longitude:(float)longitude latitude:(float)latitude {
    NSString *url;
    if (tweet) {
        url = [NSString stringWithFormat:@"http://www.tweetphoto.com/uploadandpostapiwithkey.php"];
    } else {
        url = [NSString stringWithFormat:@"http://www.tweetphoto.com/uploadapiwithkey.php"];
    }

    NSString * boundary = @"tweetPhotoBoundaryParm";
    NSMutableData *postData = [NSMutableData dataWithCapacity:[photo length] + 1024];
    //!!!Here is the error!!!!                      
    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

    NSString * userNameString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"username\"\r\n\r\n%@", [prefs stringForKey:@"username_preference"]];
    NSString * passwordString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"password\"\r\n\r\n%@", [prefs stringForKey:@"password_preference"]];
    NSString * apiString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"api_key\"\r\n\r\n3eceaa7c-6d4d-41ab-be90-2a780e2d1961"];
    NSString * messageString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"message\"\r\n\r\n%@", message];
    NSString * tagsString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"tags\"\r\n\r\n%@", tags];
    NSString * latString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"latitude\"\r\n\r\n%f", latitude];
    NSString * longString = [NSString stringWithFormat:@"Content-Disposition: form-data; name=\"longitude\"\r\n\r\n%f", longitude];
    NSString * boundaryString = [NSString stringWithFormat:@"\r\n--%@\r\n", boundary];
    NSString * boundaryStringFinal = [NSString stringWithFormat:@"\r\n--%@--\r\n", boundary];

    [postData appendData:[boundaryString dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[userNameString dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[boundaryString dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[passwordString dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[boundaryString dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[apiString dataUsingEncoding:NSUTF8StringEncoding]];
    [postData appendData:[boundaryString dataUsingEncoding:NSUTF8StringEncoding]];
    //(...)
}

（该sendImage-梅索德是由 HTTP ：//davidjhinson.wordpress.com/2009/06/01/posting-photos-using-objective-c/ ）

控制台还这样说：的 *终止应用程序由于未捕获的异常 'NSInvalidArgumentException'，原因： '* - [UIImage的长度]：无法识别的选择发送到实例0x3b28df0'

感谢您的帮助。也许有刚刚在代码中一个愚蠢的错误由我，但请鸵鸟政策生气，因为I'm刚学编程2周半。

Answer 1

这听起来像你传递一个UIImage这个方法，而不是一个NSData块。你可以尝试登录该照片的说法？

Answer 2

究竟什么是你得到的错误？换句话说，是什么让你认为这对你的指示线的错误？

如果它崩溃，有哪些打印到控制台的错误？