[iphone][xcode]NSURL urlwithstring

[问题描述]
urlStr =[NSString stringWithFormat:@"http://XXXXX%@",@"忍耐"]];

url =[NSURL URLWithString:urlStr];

在用+ (id)URLWithString:(NSString *)URLString
新建的url 为nil
出错

［解决方法］

(NSString *)stringByAddingPercentEscapesUsingEncoding:(NSStringEncoding)encoding

urlStr =[NSString stringWithFormat:@"http://XXXXX%@",@"忍耐"]];

urlStr =[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

url =[NSURL URLWithString:urlStr];

［原因］
+ (id)URLWithString:(NSString *)URLString
This method expects URLString to contain any necessary percent escape codes, which are ‘:’, ‘/’, ‘%’, ‘#’, ‘;’, and ‘@’. Note that ‘%’ escapes are translated via UTF-8.

使用stringByAddingPercentEscapesUsingEncoding:
把Nsstring转换成NSUTF8StringEncoding