ios – NSString cString已被弃用.什么是替代品？

我有另一个新手问题.

我写了一段代码,将Nsstring转换为NSMutableData,以模拟一个webService结果.

但事实证明,cString已被弃用.你可以帮我更换吗？
这是我的代码

Nsstring *testXMLDataString = 
@"<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
    etc....
"</SOAP-ENV:Envelope>";

//Replace webData Received from the web service with the test Data
NSMutableData *testXMLData = [NSMutableData dataWithBytes:[testXMLDataString cString] length:[testXMLDataString length]];
[webData setData:testXMLData];

解决方法

>从字符串获取原始字节.
>获取UTF8编码中这些字节的长度.
>使用dataWithBytes：length：方法创建NSData对象.

const char *rawBytes = [testXMLDataString UTF8String];
const NSUInteger length = [testXMLDataString lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
NSAssert(length > 0,@"Couldn't convert to UTF-8");

NSMutableData *testXMLData = [NSMutableData dataWithBytes:rawBytes length:length];
[webData setData:testXMLData];