以编程方式从服务器下载.ashx文件

Question

我正在尝试从我的ipad应用程序中下载服务器上的.ashx文件。

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.



NSString *file = [NSString stringWithFormat:@"http://url/Script.ashx"];
NSURL *fileURL = [NSURL URLWithString:file];

NSURLRequest *req = [NSURLRequest requestWithURL:fileURL];
NSURLConnection *conn = [NSURLConnection connectionWithRequest:req delegate:self];
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    [self.fileData setLength:0];
  //  self.totalFileSize = [NSNumber numberWithLongLong:[response expectedContentLength]];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [self.fileData appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSArray *dirArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,    NSUserDomainMask, YES);
    NSLog(@"%@", [dirArray objectAtIndex:0]);
    NSString *path = [dirArray objectAtIndex:0];
    NSString *dataPath = [path stringByAppendingPathComponent:@"Script.ashx"];
    dataPath = [dataPath stringByStandardizingPath];  
    if ([self.fileData writeToFile:dataPath options:NSAtomicWrite error:nil] == NO) {
        NSLog(@"writeToFile error");
    }
    else {
        NSLog(@"Written!");
    }
}

上述代码有错误吗？请帮忙。