NSCocoaErrorDomain问题.

Question

我正在尝试获取url的源代码,以便我可以解析HTML代码以获取信息.我有以下代码:

 NSURL *url = [NSURL URLWithString:@"http://www.google.com"];
 NSError *err = nil;
 NSString *urlContents = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&err];
 if(err){
    NSLog(@"err %@",err);
 }
 NSLog(@"urlContents %@", urlContents);

此代码在模拟器上完美运行,但在设备上我收到以下错误:

err Error Domain=NSCocoaErrorDomain Code=256 "The operation couldn’t be completed. (Cocoa error 256.)" UserInfo=0x167150 {NSURL=http://www.google.com}

Answer 1

这通常意味着互联网已关闭您的设备.或者,您尝试强制加载网页的编码可能不是与NSUTF8String编码匹配的编码.

尝试将代码更改为:

NSURL *url = [NSURL URLWithString:@"http://www.google.com"];
NSError *err = nil;
NSStringEncoding encoding;
NSString *urlContents = [NSString stringWithContentsOfURL:url usedEncoding:&encoding error:&err];
if(urlContents)
{
    NSLog(@"urlContents %@", urlContents);
} else {
    // only check or print out err if urlContents is nil
    NSLog(@"err %@",err);
}