Można użyć tej base64.h i base64.m klasę zdekodować do base64 ciąg.
base64.h
#import <Foundation/Foundation.h>
@interface NSData (Base64)
+ (NSData *)dataWithBase64EncodedString:(NSString *)string;
- (id)initWithBase64EncodedString:(NSString *)string;
- (NSString *) base64Encoding;
- (NSString *) base64EncodingWithLineLength:(unsigned int) lineLength;
@end
base64.m
#import "base64.h"
static char encodingTable[64] = {
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/' };
@implementation NSData (VQBase64)
- (id)initWithString:(NSString *)string {
if (self = [super init]) {
[self initWithBase64EncodedString:string];
}
return self;
}
+ (NSData *) dataWithBase64EncodedString:(NSString *) string {
return [[[NSData allocWithZone:nil] initWithBase64EncodedString:string] autorelease];
}
- (id) initWithBase64EncodedString:(NSString *) string {
NSMutableData *mutableData = nil;
if(string) {
unsigned long ixtext = 0;
unsigned long lentext = 0;
unsigned char ch = 0;
unsigned char inbuf[4], outbuf[3];
short i = 0, ixinbuf = 0;
BOOL flignore = NO;
BOOL flendtext = NO;
NSData *base64Data = nil;
const unsigned char *base64Bytes = nil;
// Convert the string to ASCII data.
base64Data = [string dataUsingEncoding:NSASCIIStringEncoding];
base64Bytes = [base64Data bytes];
mutableData = [NSMutableData dataWithCapacity:[base64Data length]];
lentext = [base64Data length];
while(YES) {
if(ixtext >= lentext) break;
ch = base64Bytes[ixtext++];
flignore = NO;
if((ch >= 'A') && (ch <= 'Z')) ch = ch - 'A';
else if((ch >= 'a') && (ch <= 'z')) ch = ch - 'a' + 26;
else if((ch >= '0') && (ch <= '9')) ch = ch - '0' + 52;
else if(ch == '+') ch = 62;
else if(ch == '=') flendtext = YES;
else if(ch == '/') ch = 63;
else flignore = YES;
if(! flignore) {
short ctcharsinbuf = 3;
BOOL flbreak = NO;
if(flendtext) {
if(! ixinbuf) break;
if((ixinbuf == 1) || (ixinbuf == 2)) ctcharsinbuf = 1;
else ctcharsinbuf = 2;
ixinbuf = 3;
flbreak = YES;
}
inbuf [ixinbuf++] = ch;
if(ixinbuf == 4) {
ixinbuf = 0;
outbuf [0] = (inbuf[0] << 2) | ((inbuf[1] & 0x30) >> 4);
outbuf [1] = ((inbuf[1] & 0x0F) << 4) | ((inbuf[2] & 0x3C) >> 2);
outbuf [2] = ((inbuf[2] & 0x03) << 6) | (inbuf[3] & 0x3F);
for(i = 0; i < ctcharsinbuf; i++)
[mutableData appendBytes:&outbuf[i] length:1];
}
if(flbreak) break;
}
}
}
self = [self initWithData:mutableData];
return self;
}
- (NSString *) base64Encoding {
return [self base64EncodingWithLineLength:0];
}
- (NSString *) base64EncodingWithLineLength:(unsigned int) lineLength {
const unsigned char *bytes = [self bytes];
NSMutableString *result = [NSMutableString stringWithCapacity:[self length]];
unsigned long ixtext = 0;
unsigned long lentext = [self length];
long ctremaining = 0;
unsigned char inbuf[3], outbuf[4];
unsigned short i = 0;
unsigned short charsonline = 0, ctcopy = 0;
unsigned long ix = 0;
while(YES) {
ctremaining = lentext - ixtext;
if(ctremaining <= 0) break;
for(i = 0; i < 3; i++) {
ix = ixtext + i;
if(ix < lentext) inbuf[i] = bytes[ix];
else inbuf [i] = 0;
}
outbuf [0] = (inbuf [0] & 0xFC) >> 2;
outbuf [1] = ((inbuf [0] & 0x03) << 4) | ((inbuf [1] & 0xF0) >> 4);
outbuf [2] = ((inbuf [1] & 0x0F) << 2) | ((inbuf [2] & 0xC0) >> 6);
outbuf [3] = inbuf [2] & 0x3F;
ctcopy = 4;
switch(ctremaining) {
case 1:
ctcopy = 2;
break;
case 2:
ctcopy = 3;
break;
}
for(i = 0; i < ctcopy; i++)
[result appendFormat:@"%c", encodingTable[outbuf[i]]];
for(i = ctcopy; i < 4; i++)
[result appendString:@"="];
ixtext += 3;
charsonline += 4;
if(lineLength > 0) {
if(charsonline >= lineLength) {
charsonline = 0;
[result appendString:@"\n"];
}
}
}
return [NSString stringWithString:result];
}
@end
Proszę sprawdzić i daj mi znać, jeśli jakiś problem.
Budowanie tablicy bajtów w pliku NSData lub NSMutableData, a następnie użycie kodu takiego jak [this] (http://stackoverflow.com/questions/392464/any-base64-library-on-iphone-sdk/4727124#4727124) to droga do przebycia. Jeśli podzielisz się tym, czego faktycznie próbowałeś, być może ktoś wskaże ci, gdzie popełniłeś błąd. – Anomie