iOS

自iOS9以后字符串的解码方法  - (nullable NSString *)stringByAddingPercentEscapesUsingEncoding:(NSStringEncoding)enc 就被

- (nullable NSString *)stringByAddingPercentEncodingWithAllowedCharacters:(NSCharacterSet *)allowedCharacters方法给代替了。

具体的实现的方法如下：

     //定义一个字符串

    NSString *str = @"http://apis.haoservice.com/weather?cityname=北京&key=c056e50a2bde4478a1a31ae491799607";

    //把字符串转换为NSCharacterSet类型

        NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:str];

   // 再根据NSCharacterSet类型转换字符串的中文为相应的编码，

        NSString *encodedValue = [str stringByAddingPercentEncodingWithAllowedCharacters:set];

         NSLog(@"%@",encodedValue);

 运行结果如下：

encodedValue = http://apis.haoservice.com/weather?cityname=%E5%8C%97%E4%BA%AC&key=c056e50a2bde4478a1a31ae491799607。