Objective-C的 - 检查是否存在URL [英] Objective-C - Checking if URL exists

问题描述

我有一个for循环当前循环4次。

I have a for-loop that currently loops 4 times.

//Add all the URLs from the server to the array
    for (int i = 1; i <= 5; i++){
        NSString *tempString = [[NSString alloc] initWithFormat : @"http://photostiubhart.comoj.com/GalleryImages/%dstiubhart1.jpg", i];
        [myURLS addObject: [NSURL URLWithString:tempString]];
        [tempString release];
    }

正如你可以看到网址中有一个数字，得到1每次循环递增，以创建一个新的URL在哪里下的图像会。然而，图像的服务器上的量不一定会如图4所示，它可能是一个更大量或甚至更少。我的问题是这样的，是有办法，我可以检查是否有图像存储在网址是什么？如果没有，破环和继续执行程序

As you can see the URL has a digit in it that get incremented by 1 each loop to create a new URL where the next image will be. However, the amount of images on the server won't necessarily be 4, it could be a lot more or even less. My problem is this, is there a way I can check if there is an image stored at the URL? And if there is not, break the loop and continue program execution?

谢谢，

杰克

推荐答案

下面是想法检查与HTTP响应

Here is idea to check with HTTP response

NSURLRequest *request;
NSURLResponse *response = nil;
NSError **error=nil; 
NSData *data=[[NSData alloc] initWithData:[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:error]];
NSString* retVal = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
// you can use retVal , ignore if you don't need.
NSInteger httpStatus = [((NSHTTPURLResponse *)response) statusCode];
NSLog(@"responsecode:%d", httpStatus);
// there will be various HTTP response code (status)
// you might concern with 404
if(httpStatus == 404)
{
   // do your job
}

或

while(httpStatus == 200){
    static int increment = 0;
    increment++;
    // check other URL yoururl/somthing/increment++
}

但是这将是缓慢的。我的建议是，如果你使用的是自己的网络服务器，那么，你可以先发送所有的图像信息。我敢肯定，你在annonymous或其他网站做这个工作:)
让我知道，如果它可以帮助你与否

but it will be slow. what my suggestion is, if you are using your own webserver, then, you can send all the image information initially. I'm sure you are doing this job on annonymous or other website :) Let me know if it helps you or not

这篇关于Objective-C的 - 检查是否存在URL的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！