Conversions between types of nsstring/nsdata/char*

Conversions between types of nsstring/nsdata/char*

Transferred from: http://www.cnblogs.com/pengyingh/articles/2341880.html

NSString converted to a Unicode String: (nsstring*) fname = @ "Test"; char fnamestr[10];memcpy (FNAMESTR, [fname cstringusingencoding:nsunicodestringencoding], ([fname length]));

Compared to strcpy, memcpy is not going to end up with ' n ', but will definitely copy the nth bytes

nsstring Conversion to char * NSString * str= @ "Test"; const char * a =[STR utf8string];

3.char * converted to NSString

NSString *str=[nsstring stringwithcstring  encoding:nsutf8stringencoding];

char * Conversion NSData method One:   char * a = (char*) malloc (sizeof (byte) *16);   NSData *data = [NSData datawithbytes:a   Length:strlen (a)]; method Two:    convert to NSString:-(ID) initwithutf8string: (const char *) bytes    nsdata Conversion char *  nsdata data;  nsdata conversion nsstring;

nsdata* data;

nsstring* astr= [NSString alloc] Initwithdata:data encoding:nsasciistringencoding];

nsstring Transforming NSData Objects nsdata* xmlData = [@ "TestData" datausingencoding:nsutf8stringencoding];http://blog.sina.com.cn/s/articlelist_ 1256141290_14_1.html

NSString Conversion Nsurl  

Nsurl *url = [Nsurl urlwithstring:[str   stringbyaddingpercentescapesusingencoding:nsutf8stringencoding];

NSString *urlstring=[@ "http://www.google.com/search?client=safari&rls=en&q= Search &ie=utf-8&oe=utf-8 [Stringbyaddingpercentescapesusingencoding:nsutf8stringencoding];

Nsurl Conversion NSString

Nsurl *url=[nsurl urlwithstring:urlstring];

NSString *s=[[url absolutestring] stringbyreplacingpercentescapesusingencoding:nsutf8stringencoding];

Nsarray *arr = [urlstr componentsseparatedbystring:@ "&"];
Nsurl *url = [Nsurl Urlwithstring:[[arr objectatindex:0] stringbyaddingpercentescapesusingencoding: Nsutf8stringencoding]];
Nsmutableurlrequest *request = [Nsmutableurlrequest Requestwithurl:url];
[Request sethttpmethod:@ "POST"];

Nsmutablearray *_array = [[Nsmutablearray alloc] initwithcapacity:0];
for (int i = 1; i < [arr count]; ++i) {
NSString *str = [arr objectatindex:i];
[_array ADDOBJECT:STR];
}
[_array componentsjoinedbystring:@ "&"];
NSData *data = [[_array componentsjoinedbystring:@ ' &] datausingencoding:nsasciistringencoding];
[Request Sethttpbody:data];

Send requests and get data from server feedback
NSData *urldata = [Aesencdecviewcontroller Get:url];

The first conversion of NSData data to char* string
char * test = (char*) [urldata bytes];
std::string old = Deaes (test);

The second conversion nsdata to the char* string in the UTF8 encoded NSString
NSString *desstr = [[NSString alloc] Initwithdata:urldata encoding:nsutf8stringencoding];
const char *desresult = [Desstr utf8string];
std::string old = Deaes (Desresult);

Decrypting a character string into clear text
NSString *oldstr = [[NSString alloc] InitWithCString:old.c_str ()];

Many times the software read the Chinese page encoding set is gb2312, so the display is garbled. You need to convert the NSString text encoding

1 Nsurl *url = [Nsurl urlwithstring:urlstr];
2 NSData *data = [NSData Datawithcontentsofurl:url];    
3 Nsstringencoding enc = cfstringconvertencodingtonsstringencoding (kcfstringencodinggb_18030_2000);    
4 NSString *retstr = [[NSString alloc] Initwithdata:data Encoding:enc];

Conversions between types of nsstring/nsdata/char*