检查URL是否有http：//前缀 [英] Check if an URL has got http:// prefix

问题描述

在我的应用程序中，当用户添加一个对象时，也可以为该对象添加一个链接，然后可以在webView中打开该链接。

我试过保存没有http：//前缀的链接，然后在webView中打开但无法打开它！

webView开始加载之前，是否有方法检查保存的URL是否有http： // 字首？如果它没有得到它，我怎么能在URL中添加前缀？

谢谢！

In my application, when the user add an object, can also add a link for this object and then the link can be opened in a webView.
I tried to save a link without http:// prefix, then open it in the webView but that can't open it!
Before webView starts loading, is there a method to check if the URL saved has got http:// prefix? And if it hasn't got it, how can I add the prefix to the URL?
Thanks!

推荐答案

您可以在NSString上使用 - （BOOL）hasPrefix：（NSString *）aString 方法查看包含您的URL的NSString是否以http：//前缀开头，如果没有添加前缀。

You can use the - (BOOL)hasPrefix:(NSString *)aString method on NSString to see if an NSString containing your URL starts with the http:// prefix, and if not add the prefix.

NSString *myURLString = @"www.google.com";
NSURL *myURL;
if ([myURLString.lowercaseString hasPrefix:@"http://"]) {
    myURL = [NSURL URLWithString:myURLString];
} else {
    myURL = [NSURL URLWithString:[NSString stringWithFormat:@"http://%@",myURLString]];
}

我目前离开了我的mac，无法编译/测试这个代码，但我相信上面应该有效。

I'm currently away from my mac and can't compile/test this code, but I believe the above should work.

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