iOS 字符串常用编码互相转换

/// 汉字 UTF8 互转
NSString* strA = [@"%E4%B8%AD%E5%9B%BD" stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *strB = [@"中国" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"%@",strA); // 中国
NSLog(@"%@",strB); // %E4%B8%AD%E5%9B%BD

/// Unicode 转汉字
NSString *content = @"\\u4e2d\\u56fd";
content = [self replaceUnicode:content];
NSLog(@"%@",content); // 中国

- (NSString *)replaceUnicode:(NSString *)unicodeStr {

NSString *tempStr1 = [unicodeStr stringByReplacingOccurrencesOfString:@"\\u"withString:@"\\U"];
NSString *tempStr2 = [tempStr1 stringByReplacingOccurrencesOfString:@"\""withString:@"\\\""];
NSString *tempStr3 = [[@"\""stringByAppendingString:tempStr2]stringByAppendingString:@"\""];
NSData *tempData = [tempStr3 dataUsingEncoding:NSUTF8StringEncoding];
NSString* returnStr = [NSPropertyListSerialization propertyListFromData:tempData
mutabilityOption:NSPropertyListImmutable
format:NULL
errorDescription:NULL];

return [returnStr stringByReplacingOccurrencesOfString:@"\\r\\n"withString:@"\n"];

}