如何确定字符串是否是Objective-C中的URL

I'm new to iPhone development and Objective-C. Using the ZBar SDK I've developed a basic app which scans a QR image from the photo album and outputs what it translates to.

我是iPhone开发和Objective-C的新手。使用ZBar SDK我开发了一个基本应用程序，它可以扫描相册中的QR图像并输出它所转换的内容。

I want to know if there is a way to take this output, determine whether it is a URL and if so open it in a web browser.

我想知道是否有办法获取此输出，确定它是否是URL，如果是这样，则在Web浏览器中打开它。

3 个解决方案

#1

NSURL's URLWithString returns nil if the URL passed is not valid. So, you can just check the return value to determine if the URL is valid.

如果传递的URL无效，NSURL的URLWithString将返回nil。因此，您只需检查返回值即可确定URL是否有效。

UPDATE

UPDATE

Just using URLWithString: will usually not be enough, you probably also want to check if the url has a scheme and a host, otherwise, urls such as al:/dsfhkgdsk will pass the test.

仅使用URLWithString：通常是不够的，您可能还想检查url是否有方案和主机，否则，诸如al：/ dsfhkgdsk之类的URL将通过测试。

So you probably want to do something like this:

所以你可能想做这样的事情：

NSURL *url = [NSURL URLWithString:yourUrlString];
if (url && url.scheme && url.host)
{
   //the url looks ok, do something with it
   NSLog(@"%@ is a valid URL", yourUrlString);
}

If you only want to accept http URLs you may want to add [url.scheme isEqualToString:@"http"].

如果您只想接受http URL，可能需要添加[url.scheme isEqualToString：@“http”]。

#2

Here is an alternative solution which I came across. You can do like this.

这是我遇到的另一种解决方案。你可以这样做。

NSURLRequest *req = [NSURLRequest requestWithURL:[NSURL URLWithString:@"yourstring"]];
bool valid = [NSURLConnection canHandleRequest:req];

Source : https://*.com/a/13650542/2513947

来源：https：//*.com/a/13650542/2513947

#3

You can look at below code to check whether a string contains website url or simple text.

您可以查看下面的代码来检查字符串是否包含网站URL或简单文本。

 NSString *getString =[[NSUserDefaults standardUserDefaults]valueForKey:@"searchKey"];
    if([getString rangeOfString:@"Www"].location == NSNotFound
       && [getString rangeOfString:@"www"].location == NSNotFound && [getString rangeOfString:@"com"].location == NSNotFound)
    {
        [companyNameTF setText:[[NSUserDefaults standardUserDefaults]valueForKey:@"searchKey"]];
    }
    else
    {
         [websiteTF setText:[[NSUserDefaults standardUserDefaults]valueForKey:@"searchKey"]];
    }

#1